HORTSCIENCE 31(7):1187-1189. 1996.

Characteristics of Litchi SeedGerminationJ.S. Prasad, Raj Kumar, Mukund Mishra, Rajesh Kumar, A.K. Singh,and U.S. Prasad1Biosciences Research Centre, Botany Department, Tej Narain Banaili College,Bhagalpur University, Bhagalpur812 007, India

i, gibberellic acid, indole-3-butyric acid,

hinensis Sonn. cultivars (Deshi, Kasba,under various conditions, viz. in soil bedsedh4w

Early Bedana ) under various conditions at either in an open container or in a polyethyl-

control was soaked in distilled water for 1 h.The beds were thoroughly irrigated in the

morning and the evening. Germination wasdetermined daily, with radicle emergence be-ing the criterion of seed germination. Seedsthat had not germinated after 8 days weresubjected to amiability assay with 1% triphenyltetrazolium chloride (TTC) solution. Data weresubjected to three-factor randomized blockdesign analysis of variance (ANOVA) withthe help of Indostat Statistical Package ac-cording to Snedecor and Cochran(1961).

Results and Discussion

Germination conditions. Germination oflitchi seed cultivars differed significantly and

e

f35 2C and 60% RH. HOW germinationcapacity was affected by physical (holdingseed in polyethylene bags or in open contain-ers at 37C and 90% RH) and chemical (ef-fects of ethephon, IBA, or GA3 treatmentswas also studied.

Materials and Methods

Fruit samples. Fully ripe fruits ( 2000) ofDeshi, Kasba, Purbi, and Early Bedanalitchi were harvested from trees in the Collegeof Agriculture, Sabour(Bhagalpur), India. Seedfrom the four cultivars was immediately sownin soil (loam) beds exposed to sunlight or

Received for publication 12 May 1995. Acceptedfor publication 4 May 1996. We thank the Principal,T.N.B. College, Bhagalpur, India, for necessarylaboratory facilities, and the CSIR, India, for finan-cial assistance to Mukund Mishra and Rajesh Kumar.The cost of publishing this paper was defrayed inpart by the payment of page charges. Under postalregulations, this paper therefore must be hereby

ene bag for 1, 2, 3, or 4 days after removal(DAR) from the fruit and then sown in sandbeds in shade.

Seeds were placed 23 cm deep in soil orsand. For each treatment there were four rep-lications with 25 seeds per replication of eachsowing condition and cultivar.

Seeds of each cultivar were soaked in 1,10,or 100 mM of IBA, GA3, or ethephon for 1 hand then sown in a sand bed under shade. The

Table 1. Percent germination of litchi seed under thr

Sand bedCultivars under shade exDeshi 92Kasba 85Purbi 84Early Bedana 60

Source of variationConditionCultivarCondition cultivar

Analysis odf

236

ErrorAdditional index words. seed germination, litchethephon

Abstract. Seed germination of four Litchi cPurbi, and Early Bedana) was studied exposed to sunlight or in shade, in sand beds filter paper. Among all, shaded, humid sanDelaying sowing seeds after removal from tLitchi seeds held in polyethylene bags up to delayed loss of seed viability. Germination Early Bedana, by IBA in Deshi and PurbCultivars responded differently to growth rcantly better than Purbi, Kasba, or Erecalcitrant nature of litchi seeds. Chemicalbutyric acid (IBA); 2-chloroethylphosphonic

The heterogeneity of litchi propagated fromseed may offer a method to develop newcultivars (Kadman and Slor, 1974; Kumar andThakur, 1981). Litchi seed germination is sen-sitive to moisture (Fu et al., 1990; Ray andSharma, 1985). However, the causes of rapidloss of seed viability by litchi and other recal-citrant seeds and the difficulties with long-term storage have not been investigated thor-oughly (Chin, 1978; Chin et al., 1984; Fu et al.,1990; Kumari-Singh and Prasad, 1991). Weinvestigated the germination of four cultivarsof L. chinensis (Deshi, Kasba, Purbi, andmarked advertisement solely to indicate this fact.1To whom reprint requests should be addressed.

HORTSCIENCE, VOL. 31(7), DECEMBER 1996xposed to sunlight or in shade, and on moist at 35 2C gave the highest germination.e fruit significantly reduced germination. days at 37 2C at 90% relative humidityas improved by ethephon in Deshi and

i, and by 100 mM GA3 in all litchi cultivars.egulators, with Deshi responding signifi-arly Bedana. These studies point to thenames used: gibberellic acid (GA3); indoleacid (ethephon).

under shade, in sand beds exposed to sunlightor under shade, and on moist filter paper atambient conditions (35 2C). Additional freshseeds were used to test several treatmentsbefore sowing: 1) seeds were held in a 40-m-thick polyethylene bag sealed with a rubberband, or were held in an open container, bothat room temperature in a humidity-controlledchamber (35 2C and 60% 4% RH asdetermined with a psychrometer); 2) seedswere sown 2,4,6, or 8 h after removal (HAR)from the fruit, in sand beds under shade; 3)seeds were held at 37C and 90% 4% RH,24zSeed germination was absent in the soil bed under shranged from 92% in Deshi to 60% in EarlyBedana sown in the sand bed under shade at35C (Table 1 ). When the soil bed was exposedto sunlight, germination never exceeded 16%.While there was a marked improvement ingermination of seeds on moist filter paper,seeds failed to germinate in the sand bedexposed to sunlight and shaded soil bed underany of these conditions. Optimum germina-tion occurred in seeds sown immediately afterremoval from the fruit. There was already asubstantial decline in the germination percent-age of all cultivars 2 h after removal from thefruit (Fig. 1). Seed held in a polyethylene bagmostly had a slower loss of germination abilitythan those held in an open container. Deshilitchi seed held in bags lost germinabilityminimally during storage, irrespective of stor-age method; in contrast, Early Bedana hadlost its capacity to germinate within 8 h afterremoval from the fruit.

Seeds of all litchi cultivars, whether held ina polyethylene bag or not at 37C and 90% RH,lost germinability to various degrees (Fig. 2).Loss in Early Bedana was the fastest. Therewas a rapid decline in germination with theincrease in days after removal, with the de-cline being mostly less for seeds held in poly-ethylene bags (Table 2). Ray and Sharma(1985) reported greater retention of viabilityin seeds stored in water rather than in air. Rayand Sharma (1987) also reported 42% viabil-ity up to 24 days when seeds had been left inthe fruit that was held in polyethylene bagsfollowing treatment with 0.05% methyl 1,2-benzimidazole carbamate (benomyl) and 6%

e conditions.z

Germination (%)Soil bed On moist filter paper

posed to sunlight under ambient conditions0 2316 5016 400 16

varianceMS F probability

16152.25 0.0011055.52 0.0001222.44 0.001

0.88875ade and sand bed exposed to sunlight.1187

S EED TE C H N O L O G Y

wax emulsion. Cull and Paxton (1982) wereable to retain viability for 1 or 2 weeks whenstored in the fruit or in moist peatmoss in afreezer. Litchi seeds in intact fruit remainviable for 4 weeks (Menzel, 1985), losingviability within a day after separation from thefruit. However, adequate soil moisture andaeration were among principal requirementsfor optimum litchi seed germination (Xia etal., 1992a, 1992b). In our study, none of theseed of any cultivar germinated in a soil bedunder shade (favoring retention of moisture,

but less aeration) or in a sand bed exposed tosunlight (favoring more aeration but rapid lossof moisture), reaffirming Xia et al. ( 1992a).Further, germination of litchi seeds was highin a sand bed under shade with regular morn-ing and evening irrigation. This high rate maybe due to the better bed aeration and theshading, which reduced water loss from the bed.

Growth regulators. Soaking litchi seedsfor 1 h in ethephon improved germinability ofDeshi at 10 mM and for Early Bedana at 1and 100 mM (Table 3). Reduced germinability

Fig. 1. Germination of litchi seeds held up to 8 h at 35C, 60% RH ( o = Deshi; m = Kasba; D = Purbi;l = Early Bedana).

Fig. 2. Germination of litchi seeds held up to 4 days atl = Early Bedana).118837C, 90% RH ( o = Deshi; m = Kasba: D = Purbi:H Owith 10 mM may be due to chance. However,1, 10, or 100 mM ethephon reduced germina-tion in Kasba and in Purbi. The improvingeffect of IBA on Deshi seed was similar tothat of ethephon. In Purbi, 10 or 100 mM IBAimproved germination. In Kasba and EarlyBedana, 1 and 10 mM IBA reduced germina-tion. GA3 at 1 mM reduced germination inDeshi, Kasba, Purbi, and Early Bedana.GA3 at 10 mM slightly improved germinationin three cultivars, the exception being Kasba.GA3 at 100 mM increased the germination ofall cultivars (Table 3), suggesting that GA3plays an important role in litchi germination.Sharma and Dhillon ( 1986) noted a decline inendogenous levels of gibberellin in litchi seedsat maturity. Such a decline may be a limitingfactor in maintenance of seed viability and/orgermination. Their results agree with those ofXia et al. (1992a) of a similar response to GA3by longan (Euphoria longan Steud.) seeds.The effect of the three growth regulators onlitchi seeds differed among cultivars.

Thus, litchi seed germination can be bestachieved on a humid sand bed under shadeimmediately after removal of the seed fromthe fruit. With an increase in time after re-moval, germination capacity is lost, reflectingthe recalcitrant nature of litchi seed. Its ger-minability can be improved by ethephon, IBA,and GA3 applications, among which GA3 plays agreater role than the other two growth regulators.

Literature Cited

Chin, H.F. 1978. Production and storage of recalci-trant seeds in the tropics. Acta Hort. 83:1721.

Chin, H.F., Y.L. Hor, and M.B.M. Lassim. 1984.Identification of recalcitrant seeds. Seed Sci. &Technol. 12:429436.

Cull, B.W. and B.F. Paxton. 1982. Litchi (Litchichinensis). Yearbook Western Austral. Nut TreeCrop Assn. 7:1321.

Fu, J.R., B.Z. Zhang, X.P. Wang, Y.Z. Qiao, andX.L. Huang. 1990. Physiological studies ondesiccation, wet storage and cryopreservation ofrecalcitrant seeds of three fruit species and theirexcised embryonic axes. Seed Sci. & Technol.18:743754.

Kadman, A. and E. Slor. 1974. Experiments withpropagation of the litchi (Litchi chinensis) inIsrael. Indian J. Hort 31:2833.

Kumar, R. and S. Thakur. 1981. Evolving new litchicultivars for Bihar (in Hindi). Adhunik KisanPatrika 11:3133.

Kumari-Singh, A. and U.S. Prasad. 1991. Dehydra-tion pattern and viability loss in seed of twocultivars of litchi (Litchi chinensis Sonn.). SeedRes. 19:4143.

Menzel, C.M. 1985. Propagation of lychee: A re-view. Scientia Hort. 25:3148.

Ray, P.K. and S.B. Shanna. 1985. Viability of Litchichinensis seeds when stored in air and in water.J. Agr. Sci. (Cambridge) 104:247248.

Ray, P.K. and S.B. Sharma. 1987. Growth, maturity,germination and storage of litchi seeds. ScientiaHort. 33:213221.

Sharma, S.B. and B.S. Dhillon. 1986. Endogenouslevel of gibberellins in relation to fruit crackingin litchi (Litchi chinensis Sonn.). J. Res. PunjabAgr. Univ. 23:432434.

Snedecor, G.W. and W.G. Cochran. 1961. Statisti-cal methods. Allied Pacific Private Limited.Bombay. p. 359-360.

Xia, Q.H., R.Z. Chen, and J.R. Fu. 1992a. Effect ofR TSCIENCE, VO L. 3 1(7), DECEMBER 1996

Table 2. Statistical analysis of germination data (ANOVA) presented in Figs. 1 and 2. Seeds A) were heldup to 8 h at room temperature (35C, 60% RH) and B) were held up to 4 days at 37C, 90% RH.

Source of variation df MS F probabilityA) Hours after removal of seed from the fruit

Replication 1 0.62 0.599Hours (H) 4 3932.30 0.000Storage method (SM) 1 1280.00 0.002Cultivars (C) 3 12826.80 0.000H SM 4 132.75 0.005H C 12 202.80 0.002SM C 3 47.33 0.002H SM C 12 31.25 0.025Error 39 2.22

B) Days after removal of seed from the fruitReplication 1 1.51 0.269Days (D) 4 12267.25 0.000Storage method (SM) 1 10035.20 0.000Cultivars (C) 3 5933.40 0.000D SM 4 674.45D

0.001

SDE

T

CDKPE

S

H C 12M C 3 SM C 12rror 39able 3. Effect of soaking in ethephon, IBA, and GA3cultivars.

GGro

Ethephonultivars Control 1 10 10eshi 92 94 100 94asba 85 73urbi 84 80arly Bedanna 60 70

ource of VariationReplicationChemical (Chem)Concentration (Con)Cultivar (C)Chem ConChem CCon CChem Con CError

47 4773 8050 80

Analysis ofdf

1233669

1847

desiccation, temperature and other factors on thegermination of lychee (Litchi chinensis Sonn.)and longan (Euphoria longan Steud.) seeds.Seed Sci. & Technol. 20: 119127.

O R TSCIENCE , VO L. 31(7), DECEMBER 199223.48 0.0251363.06 0.001

119.48 0.0251.20 (in mM) for 1 h on percent germination of four litchi

ermination (%)wth regulators (mM)

IBA GA30 l 10 100 1 10 100

93 100 94 87 94 100 54 67 80 73 73 94 80 94 94 80 87 94 40 50 60 80 70 90

varianceMS F probability

4.16 0.105661.16 0.002413.81 0.002

4282,15 0.000314.11 0.001400.44 0.001261.22 0.005111.90 0.005

1.52

Xia, Q.H., R.Z. Chen, and J.R. Fu. 1992b. Moiststorage of lychee (Litchi chinensis Sonn.) andlongan (Euphoria longan Steud.) seeds. SeedSci. & Technol. 20:269279.

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