WALNUT IMPROVEMENT PROGRAM 2019 · breeding crosses. In total, 472/1,380 nuts (34%) were predicted...

WALNUT IMPROVEMENT PROGRAM 2019

Pat J. Brown, Chuck Leslie, Ilean Battraw, Wes Hackett, Steven Lee, Kristina Toporovskaya,

Janine Hasey, Katherine Jarvis-Shean, Luke Milliron, Rachel Elkins, Sudhi Sudarshana, Abhaya

Dandekar, Malli Aradhya, MingCheng Luo, Jan Dvorak, Chuck Langley, Dan Kluepfel, Greg

Browne, Andreas Westphal

ABSTRACT

The Walnut Improvement Program develops improved scion cultivars and new rootstocks with

pathogen and abiotic stress resistance for the California walnut industry, improves our

understanding of the genetics of the crop, and maintains breeding resources. Scion breeding seeks

to generate new cultivars with improved disease and insect resistance, early harvest dates, yield,

and good kernel color. Release of an additional mid-season variety with color similar to Chandler

but with better fill and earlier harvest is in progress. Wood of advanced selections was distributed

to nurseries for further increase. We continued evaluation and propagation of scion selections on

campus and in state-wide grower trials and continued early evaluations of seedling trees. DNA

markers were developed for prediction of lateral bearing in new seedlings. We continue to develop

procedures to allow more rapid and high-throughput screening for cherry leaf roll virus (CLRV)

resistance. We examined modifications to tissue culture propagation procedures, produced

additional plants of clonal rootstock candidates, and distributed these to cooperating pathologists

for disease resistance testing. We also developed lab and greenhouse procedures for use in

screening material for Armillaria resistance. Field and tissue culture germplasm collections

continue to be maintained as a breeding resource, for use in marker development, for distribution

to commercial labs and nurseries, and for use by other walnut research projects.

OBJECTIVES

The objectives of the Walnut Improvement Program are:

● To provide the California walnut industry with improved cultivars and rootstocks

● To develop and maintain germplasm with an array of useful traits for breeding

● To develop and apply new phenotypic, genomic and molecular tools for more efficient

walnut breeding

The program consists of several projects with specific goals:

● To develop and release new scion cultivars that combine precocity (high early yield) and

early harvest dates with kernel quality, in-shell traits, and disease resistance.

● To provide solutions for blackline disease (CLRV), by moving resistance from black

walnut into commercial-quality English walnut varieties, and/or by moving tolerance from

English walnut into disease-resistant BC1 hybrid rootstocks

● To develop genetic solutions to rootstock disease and pest problems including

Phytophthora, nematodes, crown gall and Armillaria, and to improve rooting and clonal

propagation methods. Both rootstock breeding and gene insertion methods are being used

to develop new genotypes that can be multiplied and grown for pathogen resistance testing.

● To exploit new technologies to increase the efficiency of the breeding process, including

genomic information, new and more quantitative phenotyping methods, and gene

modification methods such as CRISPR.

● To maintain and augment germplasm collections for future breeding use, as a source of

foundation material for commercial labs and nurseries, for use by entomology and

pathology research projects, and as a diverse resource for development of genomic tools.

SIGNIFICANT FINDINGS

● Initiated procedures for release of selection 03-001-2357. Wood for commercial increase

is established at interested commercial nurseries. Selections 03-001-1372, 03-001-1938,

07-002-5, and others continue to be evaluated on campus and in grower trials as additional

candidates for release.

● Continued implementing low-cost, genome-wide genotyping-by-sequencing (GBS) for

every seedling in the program. Collected leaf samples for DNA extraction and analysis

from all remaining germplasm in the scion breeding program, including seedling blocks

from 2015-2019. Compared overlapping SNPs between the GBS and Axiom2 array

datasets and analyzed discrepancies with the goal of reducing technical error in both

methods.

● Deployed two DNA markers for prediction of lateral bearing in 1,380 nuts from our 2018

breeding crosses. In total, 472/1,380 nuts (34%) were predicted to be terminal-bearing and

were discarded. Of the remaining 908 nuts, 288 of them (32%) are predicted to be

homozygous for the lateral-bearing allele.

● Of the 1,511 open-pollinated seedlings from microcarpa mother trees 31.01 and 31.09 that

were genotyped for the SCRI rootstock breeding project, only 869 (58%) were determined

to be hybrids, suggesting that we need to be more diligent about removing tiny J.

microcarpa catkins.

● Established an additional selection block on the Davis campus with a replicated design for

evaluation of the most recently advanced selections and completed budding of the block

established last year.

● Continued evaluating a block of putatively CLRV-resistant scion varieties planted in 2017.

Candidates selected based on DNA marker testing and horticultural traits were grafted onto

black and English rootstocks. Grafting/budding of selections onto rootstocks and budding

CLRV virus into the English rootstocks has been completed for most trees. Additional virus

patches were added this year to accelerate blackline development and evaluation is

continuing. Genotypes exhibiting virus resistance will be considered for grower trials and

retained for use as mother trees in subsequent breeding.

● Established a trial to verify the CLRV response of Vlach, VX211 and RX1

● Improved greenhouse procedures for screening and identifying seedlings with cherry leaf

roll virus resistance. Screened 174 potted seedlings as potential CLRV-resistant scion

varieties using greenhouse budding, which allows year-around testing, gives a direct

evaluation of seedlings prior to field planting to accelerate the process of virus-resistance

breeding, and will contribute to improvement of the currently used marker for CLRV

resistance. An additional 173 trees were grafted with English scions and are ready for virus

patching this spring.

● Removed two field trials with transgenic crown gall-resistant rootstocks. These transgenic

rootstock selections are still being maintained in vitro.

● Initiated development of greenhouse procedures for use in identifying Armillaria-resistant

rootstock candidates.

● Modified in vitro methods and media for rootstock propagation.

PROCEDURES

Scion cultivar breeding

Most seedlings for evaluation are generated through controlled crosses. Female flowers are bagged

prior to bloom to exclude unwanted pollen. Pollen is collected, can be stored for up to one year if

necessary, and is applied to selected female flowers when receptive. The 2019 crossing design

placed priority on introducing blight and husk fly resistance while retaining early harvest dates,

kernel quality, nut traits and yield. Some open-pollinated (OP) nuts from selected mother trees are

also collected.

Seed from these crosses is collected in the fall before nut drop, air dried before storing, and chilled

until the end of harvest season. To ensure the highest possible germination rate, nuts are chipped

open at the blossom end without damaging the embryo and immersed in cold, slowly running,

water for 2 days before planting in the greenhouse. Soon after germination, seedlings are tagged

with unique barcoded IDs, and a small (< 1 cm) disc of leaf tissue is harvested for DNA extraction.

Genotyping is then performed to determine which seedlings to discard prior to planting into

seedling blocks at UC Davis.

Seedlings are planted on relatively close spacing: 6’ within row and 20’ between rows, or

approximately 360 trees/acre. In spring 2018 we changed our seedling planting scheme from a

design that groups all seedlings from a given family together, to a design that distributes each

family equally across the seedling block. We expect that the new design should be more effective

at separating genetic variation from spatial variation. Throughout the history of the classical

breeding program, trees exhibiting terminal bearing or other early defects have been culled at age

2-4, and trees with apparent low yield or other problems have been removed by age 5. Only the

remaining precocious and laterally fruitful individuals have been fully evaluated for phenology

(leafing, flowering and harvest dates), precocity, lateral bearing, yield, blight incidence, and nut

quality traits. We expect that the greatest benefits of adding a marker-assisted selection (MAS)

component to the breeding program will be achieved by culling undesirable seedlings (e.g.: those

that are predicted to be terminal bearing, have dark pellicle color, or have very late leafing) in the

greenhouse, before planting in the field. The 2019 seedling block is the first to have been pre-

selected with MAS.

The most promising seedlings are propagated onto rootstocks in selection blocks on 20’ x 20’

spacing. Early selection blocks used seedling rootstocks and four replicate scions of each seedling

selection grafted to two adjacent rootstocks per row in each of two adjacent rows. Our recent

selection blocks use clonal rootstocks (both commercial and experimental SCRI clones) and two

replicates of each seedling selection (a single tree in each of two adjacent rows). The number of

selections is increasing but not doubling, since we are also including more commercial cultivars

(eg: Chandler, Howard, Tulare, Ivanhoe, Solano) as “checks” within our selection blocks to allow

for more direct comparison with our selections. This year we harvested larger nut samples from

selection blocks (50 nuts/individual from selection blocks versus 20 nuts/individual from seedling

blocks) to allow more detailed phenotyping of nut and kernel quality traits.

The best selections are moved to grower trials for continued evaluation. Grower field trials are an

essential component of releasing a new cultivar. We continue to evaluate current trials, seek

opportunities to expand at current locations, and attempt to identify additional growers interested

in participating. This year we welcome a new grower-cooperator, Warren Walsh from Santa Clara

County, who is testing 12 blackline-resistant (CLRV-hypersensitive) scion selections. Thank you

Warren!

The annual “crackout” meeting, which was held again in 2019 after a one-year hiatus in 2018, is a

premier opportunity to share observations and expertise between growers, processors, nurserymen,

farm advisors, and members of the breeding program. Participants inspect kernel boxes and data

sheets to identify possible selections. Data available include current year field and crack-out data,

performance data from past years, and Diamond evaluations. The meeting includes discussion of

breeding priorities and program direction as well as participants’ recommendations regarding

selections and release of varieties. The next walnut crackout meeting is scheduled for

Thursday February 20, 2020.

Providing solutions to blackline disease (cherry leaf roll virus --CLRV)

Blackline disease results when a CLRV-tolerant English scion allows virus to spread through the

graft union to a CLRV-hypersensitive rootstock. Two potential solutions to blackline disease

include the development of CLRV-hypersensitive scions and the development of CLRV-tolerant

rootstocks. For many decades the backcross breeding program has targeted the first solution by

backcrossing the hypersensitivity to blackline disease found in northern California black walnut

into commercially acceptable English walnut cultivars. Crosses are conducted using the same

methods as in conventional cultivar breeding. Seedlings are first screened for potential resistance

to the cherry leaf roll virus using a DNA marker as reported in Walnut Research Reports (1998,

2003). Retained seedlings are then culled based on screening for virus resistance as well as the

same shell, kernel, yield, and horticultural traits used for conventional scion breeding.

The DNA marker, which maps to ~6.2 Mb on chromosome 14, only has a fidelity of ~90%, so the

virus resistance of backcross selections and potential parents still must be confirmed directly.

Genotyping and phenotyping more backcross individuals for virus tolerance will help identify a

better marker and ultimately identified the gene(s) conferring hypersensitivity. The process

primarily used to date is described in previous reports and involves field grafting a backcross

selection onto both black and English rootstock (two each). After the grafts are established, bark

from a CLRV-infected tree is patched into the English rootstock and into the backcross scions

grafted onto black rootstock. If a backcross selection is resistant to the virus, it will survive on the

black rootstock because the inoculum patch will be rejected, and it will die (exhibiting a black

line) on the inoculated English rootstock. Confirmed resistant, thin-shelled individuals with the

best commercial traits are then used as parents for the next generation of backcrosses to an English

walnut parent with nut and kernel quality.

In 2018 we developed a new, more rapid, CLRV resistance screening procedure that can be carried

out year-round in the greenhouse. Backcross and English seedlings are approach-grafted when

they are only a few weeks old, with soft green stems. Once the graft union is secure, the English

seedling is cut from its root system and becomes the scion on top of the backcross seedling to be

tested. After the graft has healed further for several weeks to ensure that the graft has been

successful, buds or bark of young virus-infected plants are budded to the established English scion.

Leaf samples from both the English scion and the backcross plant are tested for the presence of

virus and genotyped, and plants are observed for blackline development. Those that develop

blackline are resistant to the virus, and are retained for field-planting, horticultural evaluation, and

further use as parents.

Rootstock breeding

Juglans microcarpa mother trees, including DJUG31.01 and DJUG31.09 (the mothers of the SCRI

project) and DJUG29.11 (the mother of RX1) and several others, were previously grafted into one

of our English seedling blocks. Each spring we remove their catkins to promote generation of J.

microcarpa x J. regia hybrid nuts. Of 1,511 seedlings generated in 2018 and genotyped in spring

2019, only 869 (58%) were determined to be hybrids, suggesting that we need to be more diligent

about removing tiny J. microcarpa catkins. These seedlings were distributed to SCRI pathologists

for Phytophthora (Browne) and crown gall (Kluepfel) screening.

RESULTS AND DISCUSSION

Cultivar breeding

The conventional scion breeding portion of the improvement program currently includes over 5500

seedlings under evaluation in our orchard and 46 selections under evaluation at Davis and in state-

wide selection blocks and grower trials (Table 1). These include crosses for blight resistance using

the best current information available for parental selection and a set of crosses for husk fly

resistance based on information from Bob Van Steenwyk. Crosses made this year and the number

of nuts resulting from each are shown in Tables 2a, and 2b. Seedlings planted in 2019 from 2018

crosses are shown in Tables 3-4. Average phenology, yield, and nut trait data for standard varieties,

recent releases, and the advanced selections under evaluation are provided in Tables 5-7b.

Descriptions and comparative data for recent releases and advancing selections, several potential

pollinizers for Chandler, and two red-kernel selections can be found in Appendices 1 & 2.

We continue to collect data and observations on performance of previously released varieties and

industry standards. Updated information for these is included in Appendix 2 and the data tables.

With the release of Ivanhoe (2010), Solano (2013), and Durham (2016), we now have three new

varieties that address early variety quality issues and fill a range of harvest dates prior to Chandler

(Table 8). We have collected and assembled descriptive data needed to move an additional

selection (03-001-2357) with mid-season harvest date and consistently light to extra-light kernel

color forward in the release process and expect to proceed with that in the coming year. Several

additional advanced selections are showing promise as new varieties and will continue to be

evaluated and moved to additional grower trials.

Current selections with the most extensive evaluation data and most promising features are

indicated with an asterisk and potential inverse-bloom pollinizers for Chandler are indicated with

a hash mark next to the descriptions in Appendix 1. An updated comprehensive list of grower trials

and nursery blocks that include new scion selections and recent releases, their locations by county,

the year each was established, and the growers involved is included in Appendix 2.

In 2019, we applied marker-assisted selection in the breeding program for the first time. Two DNA

markers on chromosome 11 (m19 and m21 in the 2018 report) were used to identify the lateral-

bearing allele from Payne (LB1a; AAA in the 2018 report) and to discard seedlings that did not

carry at least one copy. A third marker (m16 in the 2018 report) that tags a second lateral-bearing

allele of Chinese origin (Lb1b; aaa in the 2018 report) that exists at low frequency in the breeding

program was not used, since it is not carried by any of the parents of our 2018 crosses. Therefore,

it is possible that we discarded a few open-pollinated seedlings that were lateral-bearing due to the

Chinese allele. However, we expect that virtually all of the seedlings we did plant should be lateral-

bearing.

In early spring 2020 we plan to add a marker for a leafing date quantitative trait locus (QTL) on

chromosome 1 to our marker-assisted selection procedure. Chandler is heterozygous for this QTL,

carrying one copy of the late-leafing allele and one copy of the early-leafing allele. Though

Chandler has many excellent qualities, one limitation of using Chandler as a parent is that many

of its progeny tend to be very late leafing. Using the newly-developed marker for the leafing date

QTL on chromosome 1, we will be able to select only the Chandler progeny that inherited the

early-leafing allele.

Backcross breeding for resistance to cherry leaf roll virus.

We currently retain 72 individuals under evaluation from an original population of over 800 4th

generation (BC4) crosses determined using the DNA marker to likely be resistant to CLRV. The

most promising individuals have been used as parents to produce 90 BC5 seedlings now under

field evaluation, and to produce additional open-pollinated seedlings currently going through

greenhouse testing. Field-grown trees that tested positive for the DNA marker associated with

virus resistance were grafted into a field trial for virus patch test confirmation.

The standard field-testing procedure is slow and cumbersome, and we are continuing to develop a

faster greenhouse method of CLRV resistance screening. To date we have germinated roughly

1000 backcross seedlings, grafted nearly 600 of these with English scions, and patched virus into

174 seedlings, testing the virus status of 113 of these (Table 9-10). Results so far indicate that 15

parents have offspring with a high incidence (80% or more) of tolerance and 3 with

hypersensitivity. These do not have adequate repetitions to confirm tolerance or hypersensitivity,

requiring the experiment to be continued. Death of the English scion from blackline girdling

indicates that an individual backcross seedling is CLRV resistant. By working in the greenhouse,

we are able to test seedlings throughout the winter months. This procedure has the additional

benefit of determining CLRV response in young seedlings before field planting.

To date we have had the most success using an approach graft. An approach graft is done by

planting a backcross seedling and an English seedling together in one pot, skimming off a strip of

bark from each, then, while pressing these two cut surfaces together, wrapping them. After a few

weeks we cut the English from its root system, effectively making the backcross the rootstock.

Using this type of graft means we either have to periodically cut back the growing English or

disturb the root system of the backcross in order to remove the English seedling. In order to use

other grafting techniques-namely saddle grafts- with better success, we experimented with using

various hormone combinations during the grafting process. The results did not show a significant

positive difference, but this experiment will be continued (Table 13.). Considering controls were

established later in the procedure, the results may be skewed by the grafter having more

experience.

In order to focus our attention in our blackline greenhouse experiment, we are working on

confirming the previous DNA marker results on various backcross parents. To do this we are

applying a two-step process. First we have patched virus into many of the backcrosses in our fields,

usually patching multiple on each tree. Success of the virus patch will indicate the tree is tolerant

while failure could be a sign of hypersensitivity. Confirming this hypersensitivity leads to the

second step- budding English onto these backcross parents. Those with failed virus buds will have

virus patched into the English graft sometime in Spring 2020. Table 11 shows our progress and

results so far.

Though it is usually assumed that all black walnuts (section Rhysocaryon) and their hybrids are

hypersensitive to CLRV, almost all the observed cases of blackline have involved rootstocks of

Juglans hindsii or its Paradox hybrid (J. hindsii x J. regia). We therefore initiated a field

experiment to test the CLRV response of all three clonal walnut rootstocks (Vlach, Vx211, and

RX1) grafted with Chandler, chiefly to verify that RX1, and by extension J. microcarpa, are

hypersensitive (Table 12). Because the CLRV response (tolerant or hypersensitive) of Juglans

section Cardiocaryon, which contains J. ailantifolia and J. cathayensis, remains unknown, our

greenhouse CLRV screening also includes a number of open-pollinated progeny from “Dar”, a J.

ailantifolia x J. regia hybrid.

Of special concern is the fact that none of our recent virus patches in the field or greenhouse have

resulted in blackline symptoms. In the greenhouse, we have confirmed the passage of virus through

approach grafts in juvenile plants presumed to be tolerant, but individuals that do not accumulate

virus and are presumed to be hypersensitive have not yet developed blackline. In the field, many

English rootstocks known to be tolerant are not accumulating high virus titers after several rounds

of patch-budding with virus-infected bark patches. Our source of CLRV inoculum has not changed

for many years: every year we prune back these CLRV-infected English trees to remove their

catkins and prevent them from spreading the virus. We intend to establish a new source of CLRV

inoculum from a tree obviously declining due to blackline, and to maintain the virus in backcross

seedlings verified to be tolerant. These backcross seedlings will be male-sterile so the threat of

spreading virus unintentionally will be greatly reduced.

This year we terminated a multi-year project attempting to use a transgenic RNAi approach to

generate a virus-inhibiting interstock. If successful, this interstock would have blocked virus

replication and prevented movement of the virus from scion to rootstock, thereby preventing

blackline formation. In previous years, shoots of transgenic lines selected based on marker gene

expression were rooted, grown as plants in the greenhouse, and then patch budded with virus.

However, when evaluated for presence of CLRV, all lines tested positive for virus, indicating

failure to inhibit virus replication and movement. This work is now completed and we do not

anticipate that this approach will be pursued further.

Rootstock improvement

This year we completed production of the targeted 600 SCRI genotypes for pathology screening.

Final sets of plants were delivered for Phytophthora and crown gall testing. Some dormant plants

destined for nematode field trials remain on-hand pending planting at KAC in the spring of 2020.

This year we produced and distributed approximately 1400 additional clonal rootstock plants of

diverse genotypes to the three cooperating pathologists for pathogen resistance screening and

produced another 500 clonal rootstocks of test material and controls for use by Wes Hackett in

developing Armillaria resistance screening procedures in a greenhouse growth chamber.

Wes Hackett and Steven Lee continued to develop procedures for greenhouse screening of

rootstock candidates for Armillaria resistance. Procedures were developed to culture Armillaria

on walnut tissue in the lab and work is in progress to develop reliable inoculation procedures for

greenhouse use with young potted plants. This work was supported in part by IAB funding.

In additional lab work, we examined changes to the culture media and use of NaDCC as an

alternative to bleach for cleaning contaminated microshoots. We tested addition of 1, 3, or 10 mg/L

GA3 to DKW multiplication medium for use with a variety of English, J. microcarpa, J. major,

and J. hindsii genotypes that are difficult to elongate (microshoots of 31.01, Durham, AW10,

AW17, Ivanhoe, Student #1, and newly germinating Chandler somatic embryos). RX1 was

included as an easily elongated control. In all cases, GA3 was ineffective for elongation and, in

general, shoot health was adversely affected. We also tested several media used to improve

germination or to desiccate and store somatic embryos of other crops, but preliminary results with

walnut have not been promising. To test a gentler alternative to bleach for cleaning infected

material that has been useful for pistachio, walnut microshoots were soaked in 3.0g/L NaDCC

with gentle shaking for 0.5, 1, 1.5, or 2.5 hours, and then re-cultured. Sterilization time exceeding

1 hour began to cause leaf browning. The 2.5 hour soak resulted in recovery of shoots free of

bacteria and, although leaf damage was severe, these shoots recovered and initiated new growth.

We also introduced accessions of two additional species, Juglans sigillata accession DJUG951.04

and wingnut accession DPTE1.09, the parent of the wingnut population segregating for crown gall

resistance, to culture. These accessions were chosen as representative of their species and their

genomes were previously sequenced by K. Stevens and C. Langley. Introduction of these to culture

will facilitate their use in gene expression studies.

Germplasm resources and maintenance

We continue to manage collections of both field and in vitro germplasm for use by the Walnut

Improvement Program, cooperating researchers, and commercial labs and nurseries. We supply

microshoots and somatic embryos to commercial laboratories and research cooperators on request

to support a variety of projects. We maintain a collection of nearly 2,000 genotypes in tissue culture

for rootstock and other projects. Among these are licensed commercial rootstock releases, CLRV

tolerant selections, and SCRI selections for crown gall, nematode, and Phytophthora resistance.

We also maintain an in vitro nematode population for use in nematode resistance research. We

continue to maintain several populations in our orchard for genetic study, including a Chandler x

Idaho population that was used to create a genetic map and a wingnut seedling population that

segregates for crown gall resistance. Again this year we supplied graftwood to fill a variety of

research and nursery requests.

In 2019 we removed two transgenic blocks that had been managed and monitored under a BRS

permit for many years: the older Yolo County block contained a one-acre field trial of transgenic

rootstock genotypes and the appropriate controls grafted to Chandler, while the Solano County

block contained a replicated field planting of the same rootstock genotypes, but ungrafted. During

the renewal of the BRS permit in spring 2019, BRS personnel added the following sentence to the

supplemental permit conditions: “Female flowers and nuts growing on all trees must be removed

and devitalized”. BRS later confirmed that this statement applied to the non-transgenic Chandler

flowers and nuts, which for the previous decade had not been subject to regulatory oversight. Since

it was not feasible to remove all flowers and nuts from these mature trees, we removed the

transgenic blocks. We continue to maintain the transgenic crown gall-resistant genotypes in vitro.

We have not evaluated nut samples from the NCGR Juglans collection in recent years, but due to

recent improvements in irrigation management, rodent control, and hedging of the collection, we

might be able to resume these evaluations as early as 2020.

New phenomic and genomic tools

We are continuing our efforts to develop and deploy markers to predict phenotypes in all new

seedlings in the breeding program, beginning with lateral bearing. Because ~30-40% of new

seedlings resulting from controlled crosses each year are terminal bearing, the ability to throw

these seedlings away before planting would confer a tremendous increase in efficiency and cost

savings to the breeding program.

We continue to explore the possibility of using unmanned aerial vehicles (UAVs) to measure

phenology and canopy volume of individual trees in our orchards. We are collecting RGB and

multispectral image data with a DJI Phantom 4 Professional equipped with a Micasense

RedEdge-MX, and are working with Aerobotics, a South African company dedicated exclusively

to tree crops, to extract useful phenotypes from the image data.

With help from Carlos Crisosto we purchased a walnut sheller and began developing a protocol

to measure the yield of kernel halves from different varieties in the breeding program. Though

we have only tested a small number of varieties, results so far are promising in that Chandler and

03-001-2357 yielded ~5X more kernel halves than Chico, a variety known to have poor shelling

qualities.

A collaboration with Dan Chitwood and Michelle Quigley at Michigan State University

generated three-dimensional image data using computed tomography (CT) scanning of 1,304

nuts from 172 trees in the breeding program. The data have not yet been analyzed, but the

hypothesis is that we will be able to correlate a variety’s performance in the sheller with its

three-dimensional arrangement of kernel, shell, and packing tissue as inferred from CT data.

This year we adopted the kernel imaging system developed by Irwin Donis-Gonsalez for our use

in the breeding program, with a few changes: a higher-resolution camera and new lens were

obtained, tray color was changed from black to blue, a color chart is included in every image,

and QR codes in each image identify the source tree of each kernel sample (Figure 1). We have

collected image data from kernel trays dating back to 2017 and are collaborating with Mason

Earles (Department of Viticulture and Enology) for image processing. We are optimistic that

three years of quantitative pellicle color data will be sufficient to begin greatly improving our

ability to predict pellicle color using DNA markers.

Because pellicle color is both economically important and genetically complex, we are adopting

a multi-pronged approach to investigate both pre-harvest and post-harvest factors that affect

variation in pellicle color in the breeding program. First, using Chandler and Howard scions on

RX1 in an orchard provided by Bruce Lampinen, we induced pre-harvest heat stress by applying

plastic bags around nut clusters and induced carbohydrate stress through removal of leaves, each

at four different time points. We are not finished collecting the data from this experiment.

Second, we tested how drying in a commercial oven dryer affects crack-out and color

characteristics. We used 8 walnut varieties and a selection we intend to release: Hartley,

Chandler, Howard, Tulare, Durham, Ivanhoe, Payne, Solano and 03-001-2357. Two sets of nuts

were collected from each; one set was air dried in a 72 F room while the other set was dried for

40 hours in a dryer at 95-105F followed by 7 days of air drying. Most varieties were little

affected by the dryer treatment, with the exception of Solano, for which the 40-hour sample was

noticeably darker (Figure 2). We will repeat this experiment next year with additional varieties.

Third, we will store all 2019 kernel trays at 30C for 6 months after the crackout meeting in

February 2020, then take an additional image of each kernel tray to be able to compare side-by-

side images of the same kernels before and after the period of the 30C storage. The hope is that

these additional experiments will provide a more nuanced genetic understanding of pellicle color

in walnut and will ultimately help us develop markers to predict which varieties, like Chandler,

have good color stability.

Appendix 1. Descriptions of varieties and advanced selections.

* indicates most promising,

# indicates potential pollinizers for Chandler with inverse bloom habit

Ivanhoe (95-011-14) (67-013 x Chico) (selected 2001): Released 2010. Ivanhoe is a protogynous

variety (females bloom first) released for its very early harvest timing and extra light color. It

harvests about a week before Payne and Serr with very strong yields and an abundance of nuts set

in 3s and 4s. Harvest in the southern valley can occur in late August. It has smooth light colored

shells and produces mostly Chandler-like extra light kernels averaging 7.3 g. The shells are

relatively thin and this variety is probably not suitable for in-shell use. The seals are adequate but

should be watched. Nuts yield 57% kernel with very easy removal of halves. Ivanhoe also leafs

and blooms early in the spring, similar in time to Payne and Serr, and has similar exposure to

blight. Trees should be planted on Paradox rootstock and closer spacing than other varieties due

to Ivanhoe’s relatively small stature and trees should be managed well to maintain tree health and

nut size.

Solano (95-011-16) (67-013 x Chico) (selected 2003): Released 2013.Solano is a protandrous

(males first) early to mid-season harvesting in-shell sibling of Ivanhoe with harvest timing similar

to Vina, about a week after Payne. Solano has good yield and color and better tree structure than

Vina. The large, light colored kernels average 7.9 g. Nuts have very solid oval shells with sufficient

strength and seal for in-shell use, contain 54% kernel, and have an attractive appearance. Growers

at several locations this year experienced issues with color. Leafing and flowering dates are about

a week after Payne and similar to Vina. Trees appear to be upright and vigorous in growth habit.

Durham (93-028-20) (Chandler x PI159568) (selected 2001): Released 2016. Durham has Tulare

or earlier timing with large, oval, very attractive nuts. It leafs a week before Chandler but harvests

about two weeks earlier with good yield and has had little blight to date in trials. The smooth, light-

colored, very solid shells have solid seals, 55% kernel and an attractive appearance. The large,

very plump kernels average 8.3 g and kernel color is consistently excellent. Its shell qualities also

make it an excellent candidate for use as a mid-season in-shell alternative to Hartley. Yield is good

on mature trees but young trees appear, like Chandler, to be less precocious than Ivanhoe and

Solano.

_____________

**03-001-2357 (Chandler x Phase II) (selected 2010): This selection has consistently exhibited

strong yields and produces attractive kernels with excellent color and easy removal of halves. The

tree is protandrous, leafs nearly a week after Payne, but harvests 12 days before Chandler. Kernels

average 8.1 g and have consistently been mostly extra light in color. Shells are well filled, have an

attractive appearance, are thin but not weak, and give 58% kernel yield. Clearly it is harvesting

well before Chandler. The excellent and consistent color, fill and yield merit release, as we have

discussed at recent crack out meetings. (Trial: Scheuring, Whitney Warren, Stolp, Crane, Norene,

Sierra Gold, Burchell, Orestimba, Gilbert).

*03-001-1372 (Chandler x Phase II) (selected 2010): This mid-season protandrous selection leafs

only a few days before Chandler but harvests between Vina and Tulare and is under consideration

for release. It has a strong yield of 7.7 g kernels and excellent kernel color. The nuts average 54%

kernel with excellent removal in halves. Kernel color is Chandler-like and almost entirely light to

extra light. (Trials: Scheuring, Whitney Warren, Suchan, Burchell, McDavid, Crane, Norene,

Stolp, Spanfelner, Sierra Gold, Burchell, Orestimba, Gilbert).

*03-001-1938 (Chandler x Phase II) (selected 2010): Selected for its huge yields and early harvest

timing similar to Vina or Solano, this protandrous selection produces 7.9 g kernels with very good

kernel color. The smooth, light colored shells have good strength. Seal strength appears to be

sufficient. The attractive, round, and well-filled nuts yield 57% kernel with easy removal of halves.

This selection is under consideration for release but the leafing date is early, close to Payne, and it

needs further observation in grower trials. (Trial: Whitney Warren, Scheuring, Crane, Burchell,

Orestimba, Gilbert).

*06-005-31 (Ivanhoe x 59-124) (selected 2013): This early harvest selection leafs and harvests a

week later after Payne, has had almost no blight, and is very productive. The large, attractive, well-

filled long-oval nuts yield 55% kernel although they have fairly thick shells. The very large, shiny,

and very plump 10.5 g kernels are mostly light or extra light in color and have good removal in

halves. This is an excellent candidate and needs to be moved to additional trials. (Trial: Scheuring,

Crane, Gilbert).

**07-002-5 (91-077-6 x 93-028-20) (selected 2012): This is a short season selection that leafs out

approximately Chandler time and harvests with Tulare. It has 8.0 g plump kernels with excellent

color and outstanding ease of removal, and nuts contain 58% kernel. Nuts have smooth, light-

colored, and fairly thin shells. This selection still needs to be watched further for consistency of

yield but nut and kernel traits, near absence of blight, and phenology make this a very interesting

late-leafing selection. One of the best for color and nut appearance. (Trial: Scheuring, Suchan,

McDavid, Crane).

*07-019-4 (Ivanhoe x 95-007-13) (selected 2016): This very high yielding, short-season selection

leafs two weeks after Payne and harvests 4 days after Payne. Nuts have light colored, solid but

slightly rough, shells, solid seals, yield very easy halves, and contain 56% kernel. Kernels average

8.1 g and have excellent extra light color. Should go to grower trials.

*08-006-12 (90-026-17 x 91-077-6) (selected 2014): This is a late leafing, early harvesting

selection with excellent yield. It leafs only a few days before Chandler and harvests a week after

Payne. The tree has a male-first bloom habit and low blight incidence. The nuts have good strength

and easy removal of halves, yielding 59% kernel. Kernels have excellent color, scored almost

entirely light or extra light, and average 8.5 g. Needs to go to grower trials.

____________

# 00-006-227 (76-080 x O.P.) (Selected 2009): This early-harvest date selection with very good

yield harvests approximately with Vina. The large, mostly extra light kernels average 7.8 g and

appear to hold color well in the field and after harvest. The tree leafs a week after Payne and

produces nuts with 58% kernel. Shells are thin but sufficiently strong, like Serr. Watch the seals.

The tree is protogynous with a bloom period that is inverse of Chandler, so it could also serve as

a pollinizer for Chandler. (Trials: Scheuring, Whitney Warren, Stolp, Suchan, Burchell, McDavid,

Crane, Norene, Orestimba, Leonard, Tos).

# 04-003-143 (Chandler x O.P) (selected 2011): This selection has very strong yield and excellent

kernel color. The tree leafs mid-season and has a protogynous bloom habit that is inverse of, and

overlaps, Chandler. The large round nuts have big plump kernels averaging 8.9 g with Chandler-

like light or extra light color. Nuts have smooth, light attractive shells that yield 54% kernel with

easy removal of halves. Harvest date is only a week before Chandler. This is probably the best of

these Chandler pollinizers. (Trial: Scheuring, Crane, Leonard).

_____________

03-001-1457 (Chandler x Phase II) (selected 2010): This large vigorous tree has good yield,

harvests mid-season, and has a protandrous bloom habit. Leafing is almost a week later than Payne.

The nuts have excellent shell appearance, yield 58% kernel, and shells are thin but have sufficient

strength. The 7.8 g kernels have good color and are very easily removed in halves. Although this

selection has very strong yield, the shells can be a bit too thin, the leafing is earlier than 03-001-

1372and color is not as consistently good as that selection, which will probably be the better

choice.(Trial: Whitney Warren, Scheuring, Stolp, Crane, Orestimba).

03-001-2434 (Chandler x Phase II) (selected 2010): This protandrous tree has very good kernel

color and mid-season yield about ten days before Chandler. The plump 8.6 g kernels have been

entirely light or extra light. The well-filled nuts have hard shells and produce 56% kernel. The tree

leafs early, approximately with Payne. This selection leafs earlier than 03-001-2357 and also

harvests a few days earlier, kernel color is light but not as light as that selection. This selection

consistently shows some June drop, nuts are often a bit too well filled for easy removal, and nuts

more readily drop on the ground after hull split than03-001-2357 which tends to hold them in the

canopy. We will continue to watch this selection but 03-001-2357 is the better choice. (Trial:

Scheuring, Whitney Warren, Stolp).

03-001-2440 (Chandler x Phase II) (selected 2010): This selection is notable for its consistently

outstanding extra light kernel color and is usually among the best selections evaluated for color. It

is also one of the latest leafing of this set, leafing about 9 days after Payne and 12 days before

Chandler. The nuts yield 55% kernel, kernels are very plump and easily removed, kernel weight

averages 8.4 g, and it harvests mid-season in the Vina-Tulare period. Concerns with this selection

are blight incidence in several years, yield has never quite been up to expectations, and shells were

very thick this year. This should at least continue to be used as an outstanding color parent. (Trial:

Whitney Warren, Burchell, Orestimba, Gilbert).

05-001-94 (Ivanhoe x O.P.) (selected 2014): This selection has kernels with excellent color,

consistently extra light, and 8.3 g average weight. The tree harvests a week after Payne. Nuts have

good removal of halves and 57% kernel. It has a females-first bloom habit and leafs just after

Payne. Blight has been low and yield and color have been excellent. Watch this selection further

in the grafted block and it should be moved to grower trials.

06-017-14 (Forde x 59-124) (selected 2014): This is a large vigorous tree with outstanding yield

that leafs and harvests a week later than Payne and Ivanhoe and has not exhibited blight. It has a

male-first bloom habit. The large plump kernels average 8.2 and have very good color. Nuts have

solid seals, good strength, and yield 60% kernel.

07-021-6 (95-007-13 x Durham) (selected 2014): This is a very high yielding selection with a

Tulare time harvest date about 12 days before Chandler. The kernels have consistently excellent

color with all light or extra light scoring and average 8 g. Trees leaf a week after Payne. Previous

year’s hulls tend to stay on the tree during the dormant season. Nuts yield 59% kernel and have

thin shells but with good strength. Consider this one as an excellent color and yield replacement

for Tulare. Needs to go to grower trials.

07-029-1 (94-019-29 x 91-077-6) (selected 2012): An early harvesting selection with great yield

and 7.5 g nuts yielding 55% kernel weight and kernels with fairly good color. The early harvest

date is within a few days of Payne but the leafing is a week later. The tree has a male-first bloom

habit and has had outstanding yield. Put in grower trials.

07-029-15 (94-019-29 x 91-077-6) (selected 2014): This short-season selection is a relatively small

tree that has consistently shown outstanding yield. It leafs a week after Payne, has a male-first

bloom habit, and harvests with Payne. In spite of its heavy yields, this tree continues to exhibit

excellent nut and kernel size. Kernel weight averages 9.5 g and nuts yield 56% kernel with mostly

light and extra light color and very easy extraction in halves. However, it appears to be susceptible

to blight and has a tendency to have blanks. It should be watched further.

08-002-4 (91-090-41 x 90-031-12) (selected 2014): This is a mid-season harvesting selection that

leafs ten days after Payne with excellent yield. The outstanding kernel color has been entirely light

and extra light. Nuts average 61% kernel and contain kernels averaging 8.2 g with very easy

removal of halves. Shells are rather thin but strength and seals are good. Move it to grower trials.

08-008-28 (94-019-45 x 91-077-6) (selected 2014): Leafing 10 days after Payne and harvesting

more than two weeks before Chandler, this vigorous protogynous short-season selection has very

good yield and canopy appearance. The 8.2 g kernels have excellent color. Nuts have good shell

and seal strength, are a bit rough and yield 56% kernel. Continue watching.

08-014-3 (95-018-3 x 990-031-12) (selected 2014): This short-season selection leafs with

Chandler and harvests within 5 days of Payne. This is a vigorous tree with excellent yield, nut

size and nut appearance. The 8.3 g kernels have been entirely light to extra light in color. Shells

have good strength and seal, yielding 59% kernel with easy removal. A promising selection that

needs to go to additional trials (Trial: Crane).

08-030-11 (95-026-16 x 95-007-13) (selected 2014) This is a protandrous selection that leafs about

a week after but harvests near Payne time. The large kernels averaging 9.5 g and 56% kernel are

generally over 70% extra light in color. Hull russetting and above average shell roughness are both

potential pitfalls for this selection that will need to be watched further.

09-002-22 (91-077-6 x 94-019-29) (selected 2015) Light, smooth shells give this selection an

aesthetically pleasing appearance. This selection leafs out and harvests a whole two weeks from

Payne. Another protandrous selection with 7.9 g kernels and 56% kernel, this tree has a

consistently good yield. Kernels are on average mostly extra light in color.

09-007-22 (91-096-3 x Ivanhoe) (selected 2014): This early harvesting Ivanhoe offspring leafs ten

days after Payne, has a female-first bloom habit, and good yield within a week of Payne. The nuts

are well-filled, yielding 58% kernel. This selection has outstanding kernel color, all consistently

scoring in the extra-light category, but nut size has been consistently decreasing. Watch this one

but nut size now appears to be an issue.

09-014-13 (95-007-13 x Ivanhoe) (selected 2014): This protandrous early-harvest selection leafs

and harvests a few days after Payne with excellent yield. The nuts are light and smooth with

excellent appearance and the 7.3 g kernels have excellent shiny color with most scoring as extra

light. Nuts have good seal and shell strength, yield 56% kernel.

10-024-22 (03-001-97 x Ivanhoe) (selected 2017) Notable for its huge, light colored kernels, this

selection is protogynous. Leaf out date is 2 weeks after Payne and about a week before Chandler.

It is an inverse Chandler pollinizer. The kernel color is generally extra light, kernels weigh 9.1 g

and account for 60% of the total nut weight. It is a recent selection and will endure more years of

data collection before moving up in the charts.

Red kernel selections

95-014-3 (J. purpurea (RA1088) x Chandler) (selected 2002): A red selection with a uniform dark

red color tone and potentially easier extraction of halves than Robert Livermore. Kernels average

7.5 g and nuts yield 56% kernel. (Trial: CSU Chico, Warren, Bertagna, Sierra Gold, Silva, Conant).

Harvest date averages a few days after R. Livermore.

04-007-20 (90-027-21 x Robert Livermore) (selected 2016). This red selection has 7.8 g kernels

and nuts averaging 54% kernel weight. Nuts are well filled but kernels removal is good. Evaluate

further for uniformity of color. Shell is thinner than R. Livermore. Yield and harvest date are

expected to be better than Robert Livermore. (Trial: Sierra Gold).

Appendix 2. List of Current Field Trials of Scion Selections

Field Trials of CLRV-Resistant Selections

San Benito -

Bonturi

2003: 87-041-2, 87-262-4, 92-016-1, 93-045-1

2007: 94-022-24, 94-026-20, 95-027-19

2010: 95-027-23, 95-030-10, 03-019-9, 03-019-10

2011: 06-032-18

2013: 95-030-10, 06-003-1, 06-032-6, 06-032-13, 07-047-4, 07-047-39,

07-051-6, 07-052-2, 07-056-29, 07-058-7, 07-063-20

Corotto

2005: 93-045-1, 94-022-24, 95-027-11, 95-027-23, 95-029-4

2006: 92-016-11, 93-045-1, 95-027-19, 95-027-38, 95-029-4, 96-017-12,

96-027-8, 97-027-24, 97-027-55, 98-017-44

Contra Costa – Aram

Tennant

92-016-1, 94-022-24, 97-027-55

Walsh

2019: 95-030-10, 06-032-13, 07-036-39, 07-036-164, 07-044-4, 07-045-36,

07-047-4, 07-047-6, 07-051-49, 07-059-27, 07-063-20, 09-030-2

San Joaquin - Nouri

Barton

92-016-1, 93-045-1, 94-026-20, 95-027-19

Field Trials and Nursery Blocks of Standard Selections

Tehama - Milliron

Spanfelner-Anderson

2008: Solano

2016: 03-001-1372

H. Crain

Blight resistant variety trial

Butte –Milliron

Chico State Farm

Chico State Selection Block

Chico State Farm Trial

2004: Sexton, 91-090-41, 95-026-22

Forde block, Solano Block

Stolp

2003: 94-020-5, 94-020-35, Forde

2007: Ivanhoe, 95-026-16

2008: Solano, 00-006-54, 00-006-179, 00-011-88, 01-004-2, 01-016-11, 02-

005-870, 03-001-1098, 03-001-1747

2010: Solano, 98-002-129, 00-006-227, 01-007-1, 02-005-671, 02-005-999,

03-001-1457, 03-001-1649, 03-110-2357, 03-001-2434, 03-001-2824,

03-001-2825, 03-001-3382, 03-001-3395, 03-001-3441, 03-001-4097,

03-005-4, 04-001-390, 04-003-403, 04-007-48

2011: Durham

2016: 03-001-1372

2017: 03-001-1372

2013: Durham, 03-001-1457

Bertagna - red kernels

2006: 91-084-6, 90-024-3, 95-014-3

B. Crain

2013: Durham

Moffitt

2014: Durham

Lake – Elkins

Suchan

2007: 95-018-23, 96-014-12, 00-002-27, 00-006-48

2010: 00-006-48, 00-006-227, 03-001-977, 03-001-1098, 03-001-1372, 03-

001-3441

2011: 00-006-54, 04-003-107, 04-004-58, 04-006-92

2013: 07-002-5

Glenn – Milliron

Carriere

2007: Ivanhoe

2013: Solano, Durham, 95-007-13

Colusa - Hasey

Nickels Trial - pruning

2008: Gillet, Forde, Tulare, Chandler

Sutter-Yuba - Hasey

Whitney Warren Ranch

2001-2010: 91-077-40, 91-090-41, 92-070-12, 93-026-6, Durham, 94-016-33,

94-019-85, 94-020-35, 94-028-20, 95-007-13, Ivanhoe, Solano, Gillet,

Forde, 98-001-415, 98-001-520, 98-002-129, 00-004-44, 00-005-15,

00-005-30, 00-005-44, 00-005-144, 00-005-153, 00-006-227,

00-011-107, 01-007-2, 01-016-33, 02-005-870, 03-001-507,

03-001-665, 03-001-943, 03-001-977, 03-001-1372, 03-001-1457,

03-001-1938, 03-001-2357, 03-001-2434, 03-001-2440, 03-001-2822,

03-001-3383, 03-001-3395, 03-001-3446, 03-001-3701, 03-001-4097,

04-001-56

Gilbert

2008: Sexton, Gillet, Forde

2016: 03-001-1372, 03-001-1938, 03-001-2357, 03-001-2440, 06-005-31

2017: Durham

Sierra Gold

2011: Durham, 95-007-13, Solano, 95-026-16, 00-006-227, 00-011-107, 03-

001-977, 03-001-1372, 03-001-2556

2016: 03-001-1372, 03-001-2357, 95-014-3, 04-007-20

2017: Durham

Noreen

2001: 91-096-3, 93-026-6, 94-017-69, 94-019-29, 95-017-47

2014: Solano, Durham, 03-001-2357

2015: 03-001-1372

Leonard

2016: 00-006-227, 03-001-977, 04-003-143

Fickewirth

2016: Durham

Conant

2019: Red selections 95-014-3, 04-007-20

Yolo - Jarvis-Shean

Scheuring

2002, 2004, 2008: 90-027-21, Gillet, Forde, Sexton, Ivanhoe, Solano,

Durham, 95-007-13, 91-096-3, 04-003-143, 03-001-977, 00-006-227,

03-001-2357, 03-001-2434, 03-001-1372

2011: 00-006-54, 03-001-507, 03-001-977, 03-001-1457, 03-001-1938,

03-001-2556, 03-001-3382, 03-001-3446, 03-001-3682, 04-004-58

2012: Durham, 03-001-475, 03-001-665, 03-001-958, 03-001-985,

03-001-3701, 04-001-390, 04-003-293, 04-008-28, 05-002-233,

07-002-5, 07-005-17, 07-019-16, 07-022-30

2013: 03-001-1457, 05-002-393, 05-005-295, 05-034-11, 06-004-2,

06-005-31, 06-012-21, 06-013-20, 06-025-21, 06-026-19, 06-027-16

Martinez

2013: Solano, Durham

UCD Selection Blocks

San Joaquin - Nouri

Taylor

2005: Sexton. Gillet, Forde, 95-026-22

Calaveras - Wunderlich

McDavid

2010: 00-006-227, 00-006-48, 03-001-977, 03-001-1098, 03-001-1372, 03-

001-3441

2013: 07-002-5

Stanislaus - Arnold

MJC

2004: Sexton, Gillet, Forde, Tulare

Deardorff

2006: 91-077-6, 94-020-28, Ivanhoe, 97-003-208, 97-003-311, 97-003-319

2007: 91-090-41, 91-077-6, Durham, 94-019-85, 94-020-5, 94-020-35,

Ivanhoe, 95-026-16

Orestimba Nursery

2013: Durham, 03-001-1457

2016: 00-006-227, 03-001-1372, 03-001-1938, 03-001-2357, 03-001-2440

Burchell Nursery

2010: 00-005-30, 03-001-977

2011: 95-007-13, 95-026-16, 00-006-227, 00-011-107, 03-001-1372,

03-001-2556

2016: 00-006-227, 03-001-1372, 03-001-1938, 03-001-2357, 03-001-2440

2017: Durham

Dave Wilson Nursery

2013: Durham, 03-001-1457

2017: 03-001-2357

Merced –

Crane

2002: Sexton, 90-023-11, 90-023-37, 91-094-18, 91-096-3, Tulare

2003: 92-070-12

2004: Sexton, Forde, 95-022-26

2010: 03-001-977

2012: Solano, Durham, 03-001-1372, 00-006-227, 03-001-977, 04-003-143

2014: 03-001-1457, 03-001-1938, 03-001-2357, 05-002-233, 06-013-20,

06-005-18, 06-005-31, 06-005-36, 06-025, 21, 07-002-5, 08-011-26,

08-014-3

Fresno - Culumber

KAC

2009: KAC Blight resistant variety block: Payne, Serr, PI159568, Gillet,

Ivanhoe, Solano, 91-096-3, 95-026-11

Kings - Fichtner

Headrick

91-077-6, 94-020-28, 94-020-35, Ivanhoe, Forde, Gillet

Tulare –Fichtner

Moore

2004: Ivanhoe

2012: Solano

2013: Durham, 03-001-1457

2016: R. Livermore

Table 1. Number of individual crosses completed, seedlings planted, number of selections

retained, and trees remaining under evaluation by year of cross.

Year Crosses Original

seedlings Selections Under

Evaluation

(n) (n) (n) (n)

1990 15 591 - -

1991 18 493 - -

1992 15 243 - -

1993 14 116 - -

1994 15 587 - -

1995 15 758 - -

1996 7 333 - -

1997 13 611 - -

1998 5 1759 - -

1999 1 993 - -

2000 12 2503 1 -

2001 16 210 - -

2002 5 1200 - 3

2003 11 4608 4 13

2004 7 6000 1 4

2005 9 3332 2 18

2006 22 954 3 27

2007 27 1045 5 17

2008 33 929 7 25

2009 32 1187 12 86

2010 32 1081 8 99

2011 37 761 - 90

2012 60 758 - 183

2013 83 1550 3 479

2014 58 899 - 899

2015 25 2191 2191

2017 11 668 668

2018 2019

22 30

1016 2166*

1016

Total 609 39542 46 5818

*Number of nuts from this year’s crosses shown in table 2.

Table 2a. Seed generated from 2019 crosses. OP = open pollinated.

Cross # Female Parent Male Parent Number of nuts

1 05-001-94 03-001-1938 52

2 05-001-94 OP 50

3 03-001-1938 05-001-94 273

4 03-001-2440 03-001-3395 37

5 03-001-3395 03-001-2440 184

6 03-001-3395 OP 101

7 92-068-2 91-031-8 115

8 92-068-2 OP 124

9 08-008-28 07-002-5 6

10 08-008-28 OP 43

11 09-002-22 10-024-41 20

12 07-002-5 09-025-62 124

13 07-002-5 OP 93

14 07-029-15 91-031-8 22

15 07-029-15 OP 21

16 09-007-31 07-029-15 14

17 09-007-31 OP 105

18 12-051-4 07-029-15 1

19 00-006-227 91-031-8 78

20 00-006-227 OP 102

21 R. Livermore Solano 23

22 R. Livermore 09-002-22 30

23 R. Livermore OP 102

24 91-084-2 Solano 22

25 91-084-2 09-002-22 26

26 91-084-2 OP 100

27 90-024-3 Solano 13

28 90-024-3 09-002-22 16

29 90-024-3 OP 69

30 Chandler OP 200

Total 2166

Table 2b. Open pollinated seed from J. microcarpa mother trees from which catkins were

removed.

Cross # Female Parent

Male Parent Block Row Tree

Number of nuts

31 29.11 OP 2013SB 21 3 431

32 31.01 OP 2012SB 14 57 3,281

33 31.01 OP 2012SB 8 45 576

34 31.01 OP 2016SB 8 41 8

35 31.03 OP 2011Sbb 4 42 230

36 31.03 OP 2012SB 9 21 2,319

37 31.05 OP 2012SB 2 15 2,178

38 31.09 OP 2011Sbb 3 63 36

39 31.09 OP 2012SB 8 52 925

40 31.11 OP 2012SB 19 21 7

41 31.12 OP 2012SB 14 28 190

Total 10,182

Table 3. Seedlings planted on orchard spacing spring and fall 2019.

Male Parent

Female Parent

Earliest 03-001-2357 Solano 06-005-31 06-026-20 OP

Durham 30 27 189

Earliest 2

Sinensis #5 9

03-001-2357 26 174

03-001-3395 50 86

06-005-31 8 78 56

06-026-20 7 79

07-012-7 11 24

08-008-28 33

09-007-31 55

10-024-41 48

Table 4. Cross identification number of crosses made in spring of 2018 and

number of seedlings of each planted in the spring and fall 2019.

Cross # Female Parent Male Parent No. of

nuts

1 Durham Earliest 88

2 Durham 03-001-2357 31

3 Durham OP 306

4 Earliest Solano 9

5 Earliest OP 100

6 Sinensis #5 06-005-31 13

7 03-001-2357 06-026-20 52

8 03-001-2357 OP 359

9 03-001-3395 06-026-20 65

10 03-001-3395 OP 104

11 06-005-31 Earliest 14

12 06-005-31 06-026-20 100

13 06-005-31 OP 85

14 06-026-20 06-005-31 8

15 06-026-20 OP 105

16 07-012-7 06-005-31 22

17 07-012-7 OP 96

18 08-008-28 OP 37

19 09-007-31 06-005-31 1

20 09-007-31 OP 87

21 10-024-41 OP 102

22 11-011-12 OP 49

Total 1833

Table 5. Cultivar and Selection Evaluations at Davis – (Average Phenology and Yield 2009-2019)

Grafted or Leafing Pollen Shedding Pistillate Bloom % Harvest

Seedling Date DAPa 1st Peak Last Abund.b 1st Peak Last

Lateral Yield b Date DAPc

a Days after Payne leafing date at Davis; b1=low, 9=high; c Days after Payne harvest date at Davis

Cultivars Payne G 3/20 1 3/24 4/8 3/30 7 4/1 4/4 4/11 100 7 9/11 1

Hartley G 4/5 16 4/2 4/19 4/10 7 4/16 4/19 4/23 17 6 10/2 22

Idaho G 3/20 0 4/4 4/16 4/9 7 3/24 3/28 4/2 0 6 9/9 -1

Vina G 3/28 8 3/27 4/11 4/3 7 4/7 4/11 4/16 100 7 9/19 9

Serr G 3/20 0 3/24 4/5 3/28 8 3/31 4/4 4/9 23 7 9/17 7

Chandler G 4/9 20 4/4 4/24 4/13 7 4/17 4/21 4/29 100 7 10/6 25

Howard G 4/7 18 4/2 4/16 4/9 7 4/16 4/20 4/24 100 7 9/28 18

Tulare G 4/4 15 4/3 4/21 4/12 7 4/14 4/18 4/21 100 7 10/1 21

Durham G 3/28 9 3/27 4/15 4/5 7 4/12 4/15 4/19 100 7 9/20 10

Ivanhoe G 3/17 -2 3/30 4/15 4/7 8 3/17 3/23 3/30 100 8 9/4 -6

Solano G 3/26 6 3/25 4/13 4/1 8 4/4 4/10 4/17 100 8 9/20 10

Gillet G 3/21 3 4/3 4/18 4/10 8 3/26 3/31 4/5 100 8 9/27 17

Selections 00-006-227 G 4/14 17 4/22 5/3 4/27 7 4/13 4/18 4/21 100 6 9/27 7

03-001-1372 G 4/7 18 4/6 4/20 4/13 7 4/16 4/20 4/24 100 7 9/26 15

03-001-1457 G 3/26 6 3/27 4/5 3/31 7 4/7 4/11 4/15 100 8 9/20 9

03-001-1938 G 3/22 2 3/24 4/6 3/30 7 4/4 4/8 4/12 100 7 9/20 10

03-001-2357 G 3/28 9 3/30 4/11 4/6 7 4/12 4/14 4/17 100 8 9/27 18

03-001-2434 G 3/20 1 3/25 4/9 3/31 7 4/4 4/7 4/11 100 7 9/23 13

03-001-2440 G 4/1 13 4/2 4/15 4/7 7 4/13 4/16 4/19 100 7 9/23 14

04-003-143 G 3/29 9 4/7 4/20 4/13 7 4/1 4/4 4/8 100 7 9/25 15

05-001-94 G 3/27 5 4/5 4/15 4/13 6 3/29 4/1 4/6 100 7 9/21 12

05-001-97 G 3/25 3 3/28 4/5 4/1 4 4/3 4/6 4/9 100 7 9/24 14

06-005-31 G 3/27 6 3/29 4/13 4/3 6 4/6 4/10 4/14 100 7 9/17 7

06-015-7 G 3/28 7 3/28 4/4 3/31 5 4/8 4/11 4/15 100 6 9/16 5

06-015-15 G 3/30 8 4/1 4/11 4/5 5 4/8 4/13 4/17 100 7 9/21 11

07-002-5 G 4/4 14 4/2 4/14 4/8 6 4/13 4/16 4/19 100 6 9/21 11

Table 5. Cultivar and Selection Evaluations at Davis – (Average Phenology and Yield 2009-2019)

Grafted or Leafing Pollen Shedding Pistillate Bloom % Harvest

Seedling Date DAPa 1st Peak Last Abund.b 1st Peak Last

Lateral Yield b Date DAPc

a Days after Payne leafing date at Davis; b1=low, 9=high; c Days after Payne harvest date at Davis

07-003-9 G 4/1 11 4/1 4/16 4/8 5 4/11 4/15 4/20 100 7 9/22 11

07-004-15 G 4/6 16 4/18 4/24 4/26 7 4/7 4/11 4/17 100 7 9/26 16

07-029-1 G 3/26 4 3/28 4/8 4/3 7 4/5 4/10 4/15 100 8 9/16 7

08-001-30 G 4/3 13 4/9 4/19 4/12 5 4/4 4/7 4/15 100 7 9/24 14

08-005-10 G 4/1 10 4/2 4/3 4/6 3 4/9 4/14 4/19 100 7 9/21 10

08-006-12 G 4/1 11 4/3 4/14 4/9 5 4/9 4/13 4/18 100 7 9/21 10

08-030-11 G 3/28 6 3/30 4/6 4/3 4 4/6 4/9 4/16 100 7 9/19 8

08-034-1 G 3/27 7 3/25 4/5 3/31 7 4/7 4/11 4/15 100 7 9/21 11

08-034-2 G 3/17 -2 3/16 4/2 3/24 7 3/29 4/3 4/9 100 7 9/15 4

09-002-22 S 4/5 17 4/2 4/15 4/9 6 4/13 4/17 4/21 100 7 9/23 14

09-004-18 S 3/27 9 3/28 4/8 4/2 5 4/8 4/12 4/17 90 6 9/18 8

09-004-39 S 3/27 8 3/26 4/4 3/30 4 4/4 4/8 4/10 100 7 9/21 12

09-004-44 S 3/31 13 3/31 4/8 4/7 4 4/6 4/10 4/15 100 6 9/19 10

09-007-22 S 3/29 10 4/3 4/16 4/9 5 3/31 4/3 4/6 100 7 9/11 2

09-007-31 S 4/3 15 4/11 4/28 4/19 6 4/4 4/9 4/14 100 7 9/14 6

09-014-4 S 3/21 3 4/1 4/11 4/9 6 3/24 3/27 4/1 100 7 9/14 5

09-014-13 S 3/24 6 3/25 4/3 3/29 4 4/4 4/8 4/12 100 7 9/12 3

09-014-14 S 3/20 2 3/28 4/9 4/4 7 3/23 3/26 3/30 92 6 9/5 -4

09-014-17 S 3/22 3 3/20 3/31 3/25 5 4/2 4/5 4/6 96 6 8/29 -12

09-025-78 S 3/25 6 3/24 4/5 3/30 6 4/3 4/6 4/11 100 7 9/16 8

10-005-3 S 3/24 5 3/26 4/4 3/31 5 4/1 4/5 4/9 100 6 9/22 12

10-006-4 S 3/27 8 3/29 4/5 4/1 3 4/5 4/10 4/14 100 6 9/18 8

10-008-63 S 3/30 11 4/1 4/14 4/6 7 4/9 4/13 4/17 100 7 9/16 6

10-020-3 S 3/27 8 4/8 4/20 4/14 4 3/30 4/2 4/6 100 6 9/17 7

10-020-17 S 3/27 8 4/6 4/21 4/12 5 3/30 4/2 4/5 100 7 9/16 6

10-020-40 S 3/27 8 4/3 4/22 4/9 6 3/30 4/3 4/9 100 6 9/17 7

10-024-22 S 4/3 15 4/16 4/22 4/22 6 4/6 4/9 4/14 100 7 9/20 10

Table 6. Cultivar and Selection Harvest Date, Nut, and Kernel Evaluations at Davis (Average 2009-2019)

Harvest Shell Average Wt. Color %

Date

bDAP

Seas Lgth

cSeal

dStrgth Thick mm

Nut (g)

Kernel (g)

% Kernel

eKernel Fill

fEase of Removal

Extra Light

Light Light Amber

Amber

d=Shell strength: 3 - poor, 5 - good, 7 - very strong b=“DAP” denotes “Days after Payne harvest at Davis e=Kernel fill: 3 - poor, 7- well c=Shell seal: 3 - poor, 5 - good, 7 - very strong f=Ease of Removal: 3 - easy, 7 - difficult

Cultivars

Payne 9/15 2 178 5 5 1.3 13.51 6.99 51.72 5 5 3 80 17 0

Hartley 10/4 22 183 5 6 1.5 15.19 7.01 46.15 4 5 19 64 18 0

Idaho 9/15 1 177 4 6 1.7 23.14 9.12 39.23 4 6 0 6 88 6

Vina 9/22 9 178 5 5 1.3 13.87 7.06 50.88 5 5 3 47 47 2

Serr 9/18 6 180 5 5 1.2 15.23 8.96 58.90 6 5 11 63 23 2

Chandler 10/8 25 182 5 5 1.3 13.98 6.87 49.11 5 4 76 22 3 0

Howard 10/1 18 177 5 6 1.4 14.56 7.40 50.74 5 5 21 59 19 1

Tulare 10/1 19 180 5 5 1.1 14.95 8.24 55.10 5 5 6 82 11 1

Durham 9/24 13 178 5 5 1.3 15.73 8.92 56.73 5 4 49 50 1 1

Ivanhoe 9/8 -4 173 5 5 1.2 13.87 7.74 55.81 5 5 41 54 5 0

Solano 9/23 11 180 5 5 1.3 15.89 8.72 54.89 6 5 41 57 2 0

Forde 10/7 24 191 5 6 1.5 16.82 8.83 52.53 6 5 29 57 12 1

Selections

95-030-10 9/20 8 178 5 5 1.2 14.36 7.59 52.73 5 5 57 41 2 0

00-006-227 9/23 9 171 5 5 1.2 13.50 7.79 57.44 5 5 53 40 7 0

03-001-1372 9/24 12 173 5 5 1.3 15.44 8.39 54.24 5 4 52 45 2 0

03-001-1457 9/21 8 179 5 5 1.2 13.80 8.04 58.29 5 4 35 60 5 0

03-001-1938 9/22 9 182 5 5 1.3 13.97 7.99 57.15 6 5 25 63 12 1



Date

bDAP

Seas Lgth

cSeal

dStrgth Thick mm

Nut (g)

Kernel (g)

% Kernel

eKernel Fill

fEase of Removal

Extra Light

Light Light Amber

Amber


03-001-2357 9/27 15 184 5 5 1.2 14.08 8.09 57.25 6 5 70 29 1 0

03-001-2434 9/24 12 186 5 6 1.3 16.00 8.91 55.63 6 5 29 66 4 0

03-001-2440 9/23 12 178 5 5 1.3 15.38 8.39 54.53 6 5 81 18 1 0

03-001-3615 9/26 12 172 5 5 1.3 13.33 7.31 54.79 5 4 100 0 0 0

03-019-9 9/15 2 178 4 4 1.0 10.95 6.97 63.61 5 4 14 76 5 5

04-003-143 9/26 13 180 5 5 1.2 16.75 8.95 53.44 5 4 27 65 7 1

05-001-94 9/18 7 177 5 5 1.2 14.53 8.32 57.20 5 4 62 35 3 0

05-001-97 9/23 10 181 5 5 1.2 13.54 7.70 56.93 6 5 48 43 6 3

06-004-5 9/25 12 180 5 5 1.3 14.65 7.62 52.02 5 4 19 81 0 0

06-005-31 9/17 5 173 5 6 1.3 19.00 10.4 55.02 6 5 31 63 4 2

06-012-21 9/20 7 177 5 5 1.3 15.42 8.33 54.08 5 5 46 36 16 2

06-015-7 9/17 4 171 5 5 1.2 13.46 7.76 57.65 5 5 45 49 5 1

06-015-15 9/21 9 177 5 5 1.1 12.20 7.28 59.63 5 5 68 27 4 1

06-017-14 9/18 5 175 5 5 1.2 13.53 8.18 60.46 6 5 16 80 4 0

06-032-27 9/24 12 174 5 5 1.2 11.45 6.24 53.55 5 4 32 41 8 18

07-002-5 9/21 9 167 5 5 1.1 13.83 8.14 58.80 5 4 49 45 6 0

07-003-9 9/24 11 176 5 5 1.1 15.03 8.30 55.16 5 5 63 29 7 1

07-004-15 9/22 9 168 5 6 1.4 16.61 8.80 52.98 6 5 20 62 15 3

07-019-4 9/16 4 166 5 5 1.2 14.43 8.13 56.38 5 5 58 39 2 1

07-021-6 9/24 11 181 5 5 1.1 13.55 7.98 58.80 5 5 52 43 2 3

07-029-1 9/16 3 172 5 5 1.2 13.44 7.45 55.39 5 5 35 55 5 4



Date

bDAP

Seas Lgth

cSeal

dStrgth Thick mm

Nut (g)

Kernel (g)

% Kernel

eKernel Fill

fEase of Removal

Extra Light

Light Light Amber

Amber


07-029-15 9/11 -1 166 5 5 1.2 16.81 9.48 56.37 5 4 43 52 5 0

07-031-4 9/18 5 173 5 5 1.2 16.03 8.69 54.23 5 5 39 49 11 1

07-044-4 10/5 23 196 5 5 1.2 15.58 9.19 58.92 6 5 9 71 19 0

07-047-4 9/29 16 190 5 5 1.2 13.60 7.68 56.44 6 5 25 63 12 0

07-047-6 9/24 11 185 5 5 1.1 11.61 6.66 57.32 5 4 29 66 5 0

07-051-49 9/25 13 179 5 5 1.2 11.93 6.43 53.96 5 4 52 45 3 0

07-063-20 9/14 2 182 5 5 1.3 14.49 7.98 54.97 6 5 23 53 24 0

07-064-4 10/1 19 172 5 6 1.3 17.23 8.68 50.31 5 4 20 68 9 3

07-068-1 10/5 22 195 5 6 1.4 13.17 7.03 53.40 7 5 26 68 6 0

08-001-30 9/22 10 171 5 5 1.2 13.19 7.65 57.95 5 5 41 53 7 0

08-002-4 9/25 12 176 5 4 1.1 13.48 8.20 60.83 5 4 66 27 6 1

08-005-10 9/18 6 171 5 5 1.2 13.87 7.66 55.20 5 5 53 45 2 0

08-006-12 9/19 7 168 5 5 1.2 14.36 8.48 59.04 5 5 26 64 7 4

08-008-28 9/21 9 168 5 5 1.2 14.58 8.16 55.92 5 5 47 50 3 0

08-014-3 9/19 6 163 5 5 1.1 14.08 8.32 58.91 5 5 42 50 8 0

08-019-11 9/20 9 165 5 4 1.0 15.30 9.44 61.65 4 4 62 35 1 1

08-030-11 9/16 3 172 5 5 1.2 16.88 9.49 56.21 5 5 77 22 1 0

08-034-1 9/21 10 178 5 5 1.2 12.94 7.90 61.00 6 5 39 56 5 0

08-034-2 9/15 4 181 5 5 1.2 15.93 9.02 56.54 5 5 42 46 11 0

09-002-22 9/23 13 171 5 5 1.3 14.63 7.90 53.96 5 5 70 26 4 0

09-004-18 9/19 7 174 5 5 1.2 14.28 7.83 54.82 5 4 62 33 5 0



Date

bDAP

Seas Lgth

cSeal

dStrgth Thick mm

Nut (g)

Kernel (g)

% Kernel

eKernel Fill

fEase of Removal

Extra Light

Light Light Amber

Amber


09-004-39 9/21 11 177 5 5 1.2 12.42 7.73 62.10 6 4 66 27 5 2

09-004-44 9/21 9 172 5 5 1.1 13.25 7.98 60.14 5 4 43 48 8 0

09-005-33 9/20 8 173 5 5 1.2 13.71 7.41 54.07 5 5 60 30 8 2

09-007-31 9/15 4 164 5 5 1.2 14.38 7.56 52.44 4 5 82 17 2 0

09-014-4 9/14 4 176 5 5 1.2 14.92 8.38 56.14 5 5 41 56 3 0

09-014-9 9/2 -9 166 5 5 1.2 13.37 7.27 54.18 5 5 74 19 6 1

09-014-12 9/24 14 179 5 5 1.2 13.67 8.06 58.82 5 5 62 37 1 0

09-014-13 9/12 2 171 5 5 1.2 12.97 7.30 56.17 5 4 70 29 1 0

09-014-14 9/5 -5 167 5 5 1.3 13.04 6.83 52.32 6 5 70 21 7 1

09-014-17 8/30 -12 160 5 5 1.2 12.34 6.95 56.40 5 5 65 28 5 2

10-001-9 9/11 -1 168 4 5 1.3 17.19 9.69 56.43 5 5 62 36 2 0

10-020-40 9/17 5 173 5 5 1.1 12.60 7.67 60.77 5 5 67 29 4 0

10-024-19 9/24 13 175 5 5 1.0 11.04 6.82 61.72 5 4 88 8 2 2

10-024-22 9/20 8 167 5 5 1.1 15.02 9.06 60.21 5 5 90 7 3 0

10-024-41 9/9 -3 177 5 5 1.2 15.30 8.66 56.60 5 5 47 48 5 0

11-033-2 9/14 -1 151 5 5 1.2 15.33 8.55 55.75 5 5 40 45 5 10

11-035-4 9/13 1 167 5 5 1.1 11.16 6.85 61.29 6 5 74 24 0 2

Table 7a. Average leafing, male and female bloom, and harvest dates of Cultivars at UC Davis

from 2009-2019 (in harvest date order).

Male Bloom ---------------Female Bloom___________

Table 7b. Leafing, male and female bloom, and harvest dates of cultivars and selections at UC

Davis during 2019 (in harvest date order).

Table 7b (continued). Leafing, male and female bloom, and harvest dates of cultivars and

Leaf March April May HarvestDate 27 29 31 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Date

CultivarsPayne 3/30 9/21

Vina 4/5 9/24

Solano 4/4 9/24

Howard 4/12 10/4

Tulare 4/11 10/4

Chandler 4/14 10/9

Selections10-024-41 3/22 9/6

09-014-9 3/29 9/8

09-014-14 3/29 9/8

09-014-17 4/1 9/8

09-014-13 3/31 9/13

07-019-4 4/4 9/16

10-020-40 4/1 9/16

06-015-7 4/2 9/17

selections at UC Davis during 2019 (in harvest date order).

Table 7b (continued). Leafing, male and female bloom, and harvest dates of cultivars and


08-030-11 3/29 9/17

09-014-4 3/30 9/17

05-001-94 3/29 9/18

06-005-31 3/29 9/18

07-002-5 4/10 9/18

05-001-97 3/28 9/20

06-015-15 3/30 9/20

07-003-9 3/29 9/20

07-029-1 4/2 9/20

08-001-30 4/4 9/20

08-005-10 3/30 9/20

08-034-1 3/30 9/20

08-034-2 3/24 9/20

00-006-227 4/8 9/22

03-001-1372 4/7 9/22

03-001-1457 4/3 9/22

selections at UC Davis during 2019 (in harvest date order).


03-001-1938 3/31 9/22

03-001-2434 3/28 9/22

03-001-2440 4/2 9/22

06-015-7 4/1 9/22

09-004-18 4/6 9/22

09-004-39 4/2 9/22

07-004-15 4/9 9/23

04-003-143 4/2 9/24

06-005-31 4/2 9/24

06-015-15 4/1 9/24

03-001-2357 4/1 9/25

08-008-28 4/9 9/25

08-001-30 4/10 9/26

06-017-14 3/29 9/27

09-002-22 4/8 9/29

Table 8. Average nut traits and phenology of newer varieties relative to older varieties at Davis

2009-2019.

Variety Nut wt. Kernel

wt. % kernel Ex Light Light Leaf Date Harvest

date

Ivanhoe 13.9 7.7 56 41 54 3/17 9/8

Serr 15.2 9.0 59 11 63 3/20 9/18

Vina 13.9 7.1 51 3 47 3/28 9/22

Solano 15.9 8.7 55 41 57 3/26 9/23

Durham 15.7 8.9 57 49 50 3/28 9/24

Howard 14.6 7.4 51 21 59 4/7 10/1

Tulare 14.9 8.2 55 6 82 4/4 10/1

Chandler 14.0 6.9 49 76 22 4/9 10/8

Table 9. Total backcross seedlings germinated, grafted, and budded with virus.

Parent genotype

Seedlings Germinated

Seedlings grafted to

English

Virus budded on English

Scion

07-044-4 143 52 0

07-045-36 120 81 0

07-047-39 77 33 0

87-041-2 36 20 6

87-262-4 24 20 6

91-016-1 2 2 1

92-016-1 12 9 6

93-045-1 2 2 1

94-026-20 9 8 4

95-027-19 12 8 5

03-016-1 9 5 5

03-019-1 3 3 2

03-019-9 17 11 9

05-016-2 2 2 1

05-018-2 4 3 1

06-003-1 7 1 0

07-036-39 2 2 2

07-036-212 1 1 1

Table 9 (continued). Total backcross seedlings germinated, grafted, and budded with virus.

Parent genotype

Seedlings Germinated

Seedlings grafted to

English

Virus budded on English

Scion

07-037-61 6 6 5

07-038-2 1 1 1

07-038-3 8 8 8

07-040-2 11 11 11

07-045-22 1 1 0

07-047-6 10 8 5

07-047-39 17 10 6

07-051-46 1 1 1

07-051-49 39 26 17

07-051-66 4 2 2

07-061-1 8 5 3

07-063-20 24 14 9

07-064-4 4 4 1

07-064-41 2 2 2

07-068-1 25 10 6

07-073-23 8 4 4

07-073-28 1 0 0

07-080-3 5 4 2

09-028-5 78 61 0

09-028-7 25 22 15

09-028-8 10 10 4

09-028-16 58 43 0

09-029-2 1 1 1

09-029-3 5 4 3

09-030-2 31 14 5

09-031-2 10 7 4

09-031-3 4 4 2

09-031-5 15 9 7

Total 1476 962 340

Table 10. Cumulative CLRV testing results for backcross (BC) seedlings grafted with an English

scion and budded with virus into the scion.

Parent genotype

Leaf samples tested for

CLRV

Number of English tested

w/o BC testing

Number of Seedlings + Eng/+ BC

Number of Seedlings +Eng/-BC

% Tested Tolerant

% Tested Hypersensitive

03-016-1 5 2 2 1 67 33

03-019-1 3 0 1 2 33 67

03-019-9 9 4 5 0 100 0

05-018-2 2 0 1 1 50 50

07-036-39 2 0 2 0 100 0

07-037-61 4 3 0 1 0 100

07-038-3 8 3 4 1 80 20

07-040-2 7 2 4 1 80 20

07-047-39 5 2 1 2 33 67

07-047-6 5 2 3 0 100 0

07-051-46 1 0 1 0 100 0

07-051-49 12 3 7 2 78 22

07-051-66 2 0 2 0 100 0

07-061-1 2 0 1 1 50 50

07-063-20 6 1 2 3 40 60

07-064-41 1 0 1 0 100 0

07-068-1 4 0 1 3 25 75

07-073-23 1 0 1 0 100 0

07-080-3 2 1 0 1 0 100

09-028-8 4 1 2 1 67 33

09-029-2 1 0 1 0 100 0

09-029-3 3 0 3 0 100 0

09-030-2 3 2 1 0 100 0

09-031-2 3 0 3 0 100 0

09-031-3 3 0 1 2 33 67

09-031-5 3 0 3 0 100 0

92-016-1 5 1 2 2 50 50

94-026-20 3 2 0 1 0 100

95-027-19 4 2 2 0 100 0

Totals 113 31 57 25

Table 11. DNA marker and virus patch success for backcross selectins currently in the UC Davis

orchard

BC Parent Block

Location Row Tree

DNA Marker

English graft

No. virus patched

No. Successful

No. Failed

% Successful

07-051-6 BC2009 3 2 2 No 2 2 0 50

07-051-46 BC2009 3 42 3 Yes 3 3 0 50

07-051-52 BC2009 3 48 2 Yes 2 2 0 50

07-073-23 BC2009 5 23 2 No 3 0 3 100

07-064-41 BC2009 4 54 2 No 3 0 3 100

07-040-2 BC2009 1 36 2 No 3 0 3 100

07-036-164 BC2009 4 110 2 No 3 0 3 100

07-045-36 BC2009 5 132 2 No 3 0 3 100

10-029-1 2012SB 6 40 5 No 3 0 3 100

09-031-5 2011SBb 6 42 5 No 3 0 3 100

09-031-3 2011SBb 6 44 5 No 3 1 2 75

09-031-2 2011SBb 6 45 5 Yes 3 0 3 100

09-030-2 2011SBb 6 47 5 No 3 2 1 60

09-030-1 2011SBb 6 48 5 Yes 3 3 0 50

09-029-5 2011SBb 6 49 5 No 3 2 1 60

09-029-4 2011SBb 6 50 5 No 4 3 1 57

09-029-3 2011SBb 6 51 5 Yes 3 3 0 50

09-029-2 2011SBb 6 52 5 Yes 4 4 0 50

09-029-1 2011SBb 6 53 5 No 2 0 2 100

09-028-16 2011SBb 6 54 5 Yes 4 1 3 80

09-028-15 2011SBb 6 55 5 Yes 3 3 0 50

09-028-14 2011SBb 6 56 5 No 3 1 2 75

09-028-13 2011SBb 6 57 5 No 3 0 3 100

09-028-12 2011SBb 6 58 5 No 4 1 3 80

09-028-9 2011SBb 6 61 5 No 4 2 2 67

09-028-8 2011SBb 6 62 5 Yes 3 0 3 100

09-028-7 2011SBb 6 63 5 No 4 1 3 80

09-028-5 2011SBb 6 65 5 No 3 0 3 100

09-028-2 2011SBb 6 68 5 No 4 2 2 67

03-019-9 BC 2017 37 1 2 Yes 3 0 3 100

03-019-9 BC 2017 37 2 2 Yes 3 0 3 100

07-047-39 BC 2017 37 3 2 No 0 0 0 0

07-047-39 BC 2017 37 4 2 Yes 3 0 3 100

07-051-49 BC 2017 37 5 2 Yes 3 0 3 100

07-051-49 BC 2017 37 6 2 Yes 3 1 2 75

Table 11 (continued). DNA marker and virus patch success for backcross selections currently in

the UC Davis orchard

Accession Block

Location Row Tree

DNA Marker

English graft

No. Virus patch

No. Successful

No. Failed

% Successful

07-059-28 BC 2017 37 7 2 Yes 3 1 2 75

07-059-28 BC 2017 37 8 2 Yes 3 1 2 75

07-063-20 BC 2017 37 9 2 Yes 3 3 0 50

07-063-20 BC 2017 37 10 2 Yes 3 3 0 50

07-064-4 BC 2017 37 11 2 No 0 0 0 0

07-064-4 BC 2017 37 12 2 Yes 4 1 3 80

07-068-1 BC 2017 37 13 2 Yes 3 2 1 60

07-080-3 BC 2017 37 14 2 Yes 3 3 0 50

07-080-3 BC 2017 37 15 2 Yes 2 2 0 50

95-030-10 BC 2017 37 16 2 Yes 3 1 2 75

95-030-10 BC 2017 37 17 2 No 0 0 0 0

03-016-1 BC 2017 37 18 3 Yes 3 3 0 50

03-016-1 BC 2017 37 19 3 Yes 0 0 0 0

06-032-27 BC 2017 37 20 2 Yes 3 3 0 50

06-032-27 BC 2017 37 21 2 Yes 3 3 0 50

07-044-4 BC 2017 37 24 2 Yes 3 0 3 100

07-044-4 BC 2017 37 25 2 Yes 3 3 0 50

07-047-4 BC 2017 37 26 2 Yes 3 2 1 60

07-047-4 BC 2017 37 27 2 Yes 3 1 2 75

07-051-35 BC 2017 37 28 2 No 0 0 0 0

07-051-35 BC 2017 37 29 2 Yes 1 0 1 100

07-068-1 BC 2017 37 30 2 Yes 4 0 4 100

07-068-1 BC 2017 37 31 2 Yes 3 0 3 100

07-064-4 BC 2017 37 32 2 Yes 2 0 2 100

07-064-4 BC 2017 37 33 2 Yes 3 0 3 100

07-052-2 BC 2017 37 34 2 Yes 3 0 3 100

07-052-2 BC 2017 37 35 2 Yes 3 0 3 100

07-059-28 BC 2017 37 36 2 Yes 2 0 2 100

07-080-59 BC 2017 37 37 2 Yes 0 0 0 0

07-080-3 BC 2017 37 38 2 Yes 2 0 2 100

07-080-3 BC 2017 37 39 2 Yes 3 0 3 100

07-059-27 BC 2017 37 40 2 Yes 1 0 1 100

07-059-27 BC 2017 37 41 2 Yes 2 0 2 100

07-047-6 BC 2017 37 42 2 Yes 3 0 3 100

DNA Marker: 1- Patch hypersensitive, 2- DNA hypersensitive, 3- Tolerant by patch test, 4- Tolerant by DNA, 5- untested Table 12. Testing commercial rootstock for hypersensitivity or tolerance to CLRV

Rootstock No. of trees No. Successful

No failed

% Successful

RX1 11 6 5 55

Vlach 11 8 3 73

VX211 16 5 11 31

Table 13. Use of growth regulators to callus grafts on greenhouse plants.

Treatment No.

Grafted No.

Successful % Successful

Kinetin 250 mg/L 46 27 58.7

BAP 250 mg/L 43 15 34.9

BAP 10 mg/L, IBA 5 mg/L 47 26 55.3

BAP 10 mg/L, IBA 2 mg/L 45 25 55.6

Control 18 10 55.6

Table 14. 2019 UCD Variety/Selection Evaluations by Diamond.

Location

Variety or

Selection

Sample

Wt.

Nuts per

sample

Avg nut

wt. (g)

% Jumbo

Sound

% Large

& Jumbo

Sound

% Mid

& Baby

Sound

%

Stain

%

Broken

% Adh

Hull

%

External

Damage

Davis GB Payne 1000 76 13.16 100% 100% 0% 0% 0% 0% 0%

Davis NS Payne 1000 89 11.24 61% 75% 12% 0% 0% 0% 0%

Davis GB Hartley 1000 75 13.33 92% 96% 1% 1% 0% 0% 1%

Davis NS Vina 1000 81 12.35 81% 90% 4% 2% 0% 0% 2%

Davis GB Chandler 1000 79 12.66 92% 99% 0% 0% 0% 0% 0%

Davis NS Chandler 1000 84 11.90 82% 92% 7% 0% 0% 0% 0%

Davis D Durham 1000 64 15.63 100% 100% 0% 0% 0% 0% 0%

Davis GB Howard 1000 78 12.82 99% 100% 0% 0% 0% 0% 0%

Davis GB Tulare 1000 77 12.99 91% 94% 0% 0% 0% 0% 0%

Davis GB Ivanhoe 1000 77 12.99 88% 91% 0% 0% 0% 0% 0%

Davis D Solano 1000 73 13.70 88% 95% 0% 0% 0% 0% 0%

Davis C Solano 1000 68 14.71 97% 97% 0% 0% 0% 0% 0%

Davis F 91-031-8 1000 46 21.74 100% 100% 0% 0% 0% 0% 0%

Davis F 95-030-10 1000 83 12.05 95% 95% 0% 0% 0% 0% 0%

Davis D 00-006-227 1000 84 11.90 94% 94% 5% 0% 0% 0% 0%

Davis D 03-001-1457 1000 90 11.11 61% 78% 19% 0% 0% 0% 0%

Davis D 03-001-2357 1000 73 13.70 96% 100% 0% 0% 0% 0% 0%

Davis D 03-001-2440 1000 73 13.70 84% 93% 4% 1% 0% 0% 1%

Davis F 04-003-143 1000 62 16.13 98% 98% 0% 0% 0% 0% 0%

Davis F 05-001-94 1000 70 14.29 100% 100% 0% 0% 0% 0% 0%

Davis F 06-005-31 1000 54 18.52 98% 100% 0% 0% 0% 0% 0%

Davis F 06-012-21 1000 69 14.49 94% 96% 0% 3% 0% 0% 3%

Davis F 06-015-15 1000 84 11.90 100% 100% 0% 0% 0% 0% 0%

Davis F 06-015-7 1000 76 13.16 99% 99% 0% 0% 0% 0% 0%

Table 14. (continued.) 2019 UCD Variety/Selection Evaluations by Diamond.

Location

Variety or

Selection

Sample

Wt.

Nuts per

sample

Avg nut

wt. (g)

% Jumbo

Sound

% Large

& Jumbo

Sound

% Mid

& Baby

Sound

%

Stain

%

Broken

% Adh

Hull

%

External

Damage

Davis F 07-002-5 1000 78 12.82 82% 99% 0% 0% 0% 0% 0%

Davis F 07-002-5 1000 75 13.33 97% 100% 0% 0% 0% 0% 0%

Davis F 07-003-9 1000 78 12.82 100% 100% 0% 0% 0% 0% 0%

Davis F 07-004-15 1000 62 16.13 98% 98% 0% 0% 0% 0% 0%

Davis F 08-001-30 1000 80 12.50 98% 98% 0% 0% 0% 0% 0%

Davis F 08-005-10 1000 84 11.90 96% 98% 1% 0% 0% 0% 0%

Davis F 08-014-3 1000 79 12.66 100% 100% 0% 0% 0% 0% 0%

Davis F 08-030-11 1000 66 15.15 98% 98% 0% 0% 0% 0% 0%

Davis Locations: GB=Germplasm Block; NS=New Stuke Block; B, C, D, E, & F = Selection Blocks B, C, D, E, & F


Location

Variety or

Selection

%

Insect

%

Mold

%

Shrivel

%

Offgrade

%

Edible

Yield

%

Total

Yield

Extra

Light Light

Light

Amber Amber RLI

Relative

Value

Davis GB Payne 0% 0% 0% 0% 57% 57% 21% 72% 8% 0% 53.8 1.11

Davis NS Payne 2% 1% 9% 5% 49% 51% 9% 24% 61% 6% 48.9 0.86

Davis GB Hartley 3% 0% 0% 2% 46% 47% 41% 28% 31% 0% 54.3 0.89

Davis NS Vina 1% 1% 2% 3% 48% 49% 6% 23% 69% 2% 46.1 0.79

Davis GB Chandler 0% 0% 1% 0% 49% 49% 82% 14% 4% 0% 57.8 1.02

Davis NS Chandler 0% 0% 1% 0% 46% 46% 81% 19% 0% 0% 59.1 0.98

Davis D Durham 0% 0% 0% 0% 57% 57% 92% 6% 3% 0% 59.6 1.21

Davis GB Howard 0% 0% 0% 0% 51% 51% 75% 20% 5% 0% 56.7 1.03

Davis GB Tulare 0% 0% 6% 1% 53% 54% 66% 34% 0% 0% 56.9 1.09

Davis GB Ivanhoe 4% 1% 4% 5% 54% 57% 66% 16% 18% 0% 55.9 1.09

Davis D Solano 3% 0% 3% 3% 53% 55% 26% 67% 7% 0% 54.0 1.03

Davis C Solano 0% 0% 3% 0% 54% 54% 23% 56% 21% 0% 53.5 1.03

Davis F 91-031-8 0% 0% 0% 0% 48% 48% 71% 12% 17% 0% 57.2 0.98

Davis F 95-030-10 0% 0% 5% 1% 52% 53% 64% 23% 13% 0% 58.5 1.10

Davis D 00-006-227 0% 0% 4% 1% 56% 56% 75% 20% 5% 0% 56.6 1.14

Davis D 03-001-1457 0% 0% 3% 1% 52% 52% 75% 22% 3% 0% 57.0 1.06

Davis D 03-001-2357 0% 0% 0% 0% 59% 59% 76% 17% 6% 0% 57.2 1.21

Davis D 03-001-2440 0% 1% 0% 1% 54% 55% 88% 10% 1% 0% 59.3 1.16

Davis F 04-003-143 0% 0% 2% 0% 53% 53% 33% 56% 11% 0% 52.7 1.00

Davis F 05-001-94 0% 0% 0% 0% 58% 58% 75% 18% 6% 0% 58.5 1.23

Davis F 06-005-31 0% 0% 0% 0% 58% 58% 70% 30% 0% 0% 56.5 1.19


Davis Locations: GB=Germplasm Block; NS=New Stuke Block; B, C, D, E, & F = Selection Blocks B, C, D, E, & F

Location

Variety or

Selection

%

Insect

%

Mold

%

Shrivel

%

Offgrade

%

Edible

Yield

%

Total

Yield

Extra

Light Light

Light

Amber Amber RLI

Relative

Value

Davis F 06-012-21 0% 0% 1% 0% 55% 56% 26% 69% 4% 1% 54.8 1.09

Davis F 06-015-15 0% 0% 0% 0% 61% 61% 78% 19% 3% 0% 59.0 1.30

Davis F 06-015-7 0% 0% 1% 0% 58% 59% 36% 54% 10% 0% 55.1 1.16

Davis F 07-002-5 0% 0% 0% 0% 61% 61% 80% 20% 0% 0% 59.2 1.30

Davis F 07-002-5 0% 0% 0% 0% 62% 62% 84% 14% 2% 0% 60.6 1.35

Davis F 07-003-9 0% 0% 0% 0% 58% 58% 61% 29% 9% 1% 57.8 1.20

Davis F 07-004-15 0% 0% 2% 0% 54% 54% 27% 38% 34% 1% 53.7 1.04

Davis F 08-001-30 0% 0% 3% 1% 58% 58% 71% 25% 4% 0% 57.9 1.20

Davis F 08-005-10 0% 0% 1% 0% 60% 60% 87% 13% 0% 0% 59.1 1.27

Davis F 08-014-3 0% 0% 0% 0% 58% 58% 70% 25% 5% 0% 57.1 1.18

Davis F 08-030-11 0% 2% 0% 1% 60% 61% 67% 25% 8% 0% 57.3 1.24

Figure 1. An example of an image generated using the new kernel imaging system

Figure 2. Comparison of Ivanhoe and Solano kernels from nuts that were previously air-dried or

dried in a dryer for 40 hours.

WALNUT IMPROVEMENT PROGRAM 2019 · breeding crosses. In total, 472/1,380 nuts (34%) were predicted...

Documents

Transcript of WALNUT IMPROVEMENT PROGRAM 2019 · breeding crosses. In total, 472/1,380 nuts (34%) were predicted...