Within-species diversity and CWR conservation · 2016. 5. 13. · Within-species diversity –Jenny...

Within-species diversity and CWR conservation Jenny Hagenblad

How diverse are organisms?

13 MAY 2016 2 Within-species diversity – Jenny Hagenblad

Populus tremula Oryza sativa

Leffler et al, 2012

Arabidopsis thaliana

How diverse are eukaryotes?


Capsella grandiflora Populus tremula Pinus radiata

Leffler et al, 2012

Arabidopsis thaliana

How diverse are plants?


Leffler et al, 2012

Algae Monocots Dicots

Genetic diversity is correlated with genome and population size


Barton et al, 2007

Genetic diversity depends on the mode of reproduction


Leffler et al, 2012

Genetic diversity – “the clay of evolution”


Crop species contain genetic variation for adaptive traits


Vanhala et al, forthcoming

But HR alleles in Swedish landrace pea are not geographically distributed...


Vanhala et al, forthcoming

Neutral genetic diversity show latitudinal structuring in Fennoscandian landrace barley


Forsberg et al, 2015. Heredity 144: 195 - 206

But putative adaptive genes are invariant in Fennoscandian barley...


Aslan et al, 2015. Crop Sci, 55:2766-2776

Within-population diversity and adaptation


Ma et al, 2010

Plant diversity


How genetically diverse are crops?


Wild progenitor Landraces Modern cultivars

Maize 0.0059 0.0049 0.0048

Maize 0.0210 - 0.0163

Rice 0.0030 0.0024 -

Rice (Indica) 0.0077 - 0.0057

Rice (Japonica) 0.0077 - 0.0037

Foxtail millet - 0.0010 0.0009

Pearl millet 0.0036 - 0.0024

Soybean 0.0030 - 0.0019

Barley 0.0014 - 0.0016

Wheat 0.0070 - 0.0050

Average 0.0067 0.0047

Landrace crops


• Lacking formal improvement

• Locally adapted

• Dynamic population structure

• Distinct identity

• Historic origin

• Associated with traditional farming systems

• Genetically diverse

Swedish historic landraces were not always more variable than modern accessions.


00,05

0,10,15

0,20,25

0,30,35

0,4

Microsatellite diversity

Leino & Hagenblad, 2010. Mol Biol Evol, 27:964-973

Genetic diversity in historical and extant barley and rye landraces.


00,10,20,30,40,50,6

Barley

Extant

Historical

Hagenblad et al, 2012. Genet Resour Crop Evol, 59: 1185 - 199

00,10,20,30,40,50,60,7

Rye

Extant

Historical

The distribution of genetic diversity in crops will depend on mode of reproduction.


barley rye

Hagenblad et al, 2012. Genet Resour Crop Evol, 59: 1185 - 199

The distribution of genetic diversity in crops will depend on the amount of seed exchange.


Leino et al, 2013. Heredity, 110: 338–346

extant accessions

historical accessions

The distribution of genetic diversity in crops will depend on the cultivation practice.


Hagenblad et al, under review

Sampling single individuals may give different impressions of the genetic diversity.


Hagenblad et al, under review

Increased omnivore and predator, but not herbivore abundance in with increased genotypic diversity in evening primrose.


Johnson et al, 2006

Yield advantages of cultivating mixtures


Crop # comparisons Minima Maxima % yield difference mixture and components

Barley 764 -34.9 39.9 2.7 ± 0.28

Oat 558 -10.0 16.5 0.7 ± 0.17

Wheat 745 -26.6 49.7 5.4 ± 0.38

Maize 92 -20.9 16.1 1.1 ± 0.67

Sorghum 63 -8.5 14.5 1.1 ± 0.72

Groundnut 115 -26.9 29.1 1.7 ± 0.92

Soybean 432 -25.6 17.9 0.8 ± 0.29

Other crops 156 -25.6 44.7 5.4 ± 0.89

Smithson & Lenné, 1996

Disease reduction from cultivating mixtures


Crop Disease average % disease reduction

Barley Powdery mildew 38,22

Barley Scald 30,65

Barley Net Blotch 35,70

Barley Rust -23,10

Wheat Leaf Blotch 37,00

Wheat Rust 29,53

Wheat Powdery mildew 52,10

Oat BYDV 47,00

Rice Blast 58,15

Sorghum Leaf Blight 33,50

Common bean Rust 13,80

Common bean Angular leaf spot 13,53

Common bean Anthacnose 6,80

Common bean Halo-blight 16,40

Smithson & Lenné, 1996

Less severe rice blast when susceptible plants were grown together with resistant plants than when grown in monoculture.


Zhu et al, 2000

monoculture

mixture

What do we know about plant within-species diversity?


• Lots of genetic diversity not visible to the naked eye.

• Plant genetic diversity span over a similar range as animal genetic diversity.

• Genetic diversity is correlated with population size.

• Outcrossing plants are more genetically diverse than selfing plants.

• Domestication is associated with a reduction in genetic diversity as is plant improvement.

What do we know about plant within-accession diversity?


• Variable within-accession genetic diversity in landraces.

• Amount of diversity and distribution of diversity depends on

– mode of reproduction

– amount of seed exchange

– cultivation practices

– ...

Why we should care about within-species diversity when it comes to CWR?


• Within-species diversity is a valuable resource in itself!

• Of interest to understand the species’ evolutionary history.

• “The clay of evolution”.

• Allows for adaptation.

• A source of phenotypic variation.

• Can lead to increased production and disease reduction.

Acknowledgements


• People

– Matti Leino

– Tytti Vanhala

– Nils Forsberg

– Selçuk Aslan

– Jenny Zie

– Erik Boström

– Hugo Oliveira

• Funding

– Formas

– Lagersbergs stiftelse

– The Swedish Board of Agriculture

– The Royal Swedish Academy of Agriculture and Forestry (KSLA)

– Carl Tryggers Foundation

– The Nilsson-Ehle foundation

– The Helge Ax:son Johnsson foundation.

www.liu.se

https://people.ifm.liu.se/jehag/HSG/

Within-species diversity and CWR conservation · 2016. 5. 13. · Within-species diversity –Jenny...

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