Acta Horticulturae Sinica ›› 2021, Vol. 48 ›› Issue (9): 1731-1742.doi: 10.16420/j.issn.0513-353x.2020-0855

• Research Papers • Previous Articles     Next Articles

Effect of Endogenous Hormone Levels and Ratios in Explants of Ten Genotypes of Cucumber on Their Regeneration in Vitro

WANG Tuantuan, GOU Chenxing, XIA Lei, ZHU Pinyu, LI Ji*(), CHEN Jinfeng   

  1. State Key Laboratory of Crop Genetics and Germplasm Enhancement,College of Horticulture,Nanjing Agricultural University,Nanjing 210095,China
  • Received:2020-11-25 Revised:2021-03-05 Online:2021-09-25 Published:2021-09-30
  • Contact: LI Ji


In order to reveal the key factor influencing the regeneration vigor of different cucumber (Cucumis sativus L.)and optimize the cucumber in vitro regeneration system. The effect of endogenous hormone levels and exogenous hormone treatments on the differentiation rate,the number and morphology of adventitious buds were investigated in cotyledon node explants of 10 different genotypes. The results showed that the differentiation rate of the 10 materials was significantly different in the absence of exogenous hormones,and the endogenous CTK level was positively correlated with the differentiation rate,with correlation coefficients were 0.4544 (0 d incubation)and 0.6110(14 d incubation),respectively. The differentiation rates of different genotypes were increased from 5.95% ~ 20.45% to 42.39% ~ 80.43% by 1.5 mg · L-16-BA treatment. Morphology observation showed there were two different types of adventitious buds,typeⅠbuds:leaf blade stretching and visible culm,typeⅡbuds:deformity bud with leaf blade and no visible culm. The proportion of the formation of typeⅠand typeⅡadventitious buds were significantly different in different genotypes. The regeneration rates of the genotypes with a high ratio of typeⅠ/Ⅱadventitious buds were significantly higher than that of the genotypes with a low ratio. Correlation analysis showed that the typeⅠ/Ⅱexplant ratio was closely correlated with the IAA/ABA ratio(R2= 0.4214),and the ratio of typeⅠ/Ⅱadventitious buds was obviously positive correlation with the rate of regeneration seedings(R2= 0.5623). For the genotype C5 and C6,which had a low typeⅠ/Ⅱexplant ratio(0.52 and 0.46),adventitious buds ratio and low rate of regeneration seedings,different proportion of exogenous NAA and ABA was added to the induction medium,it was found that typeⅠ/Ⅱexplants ratio(1.65 and 1.15),adventitious buds ratio(1.81 and 1.17)and the regeneration rate(48.57% and 53.33%)were significantly improved when the NAA/ABA ratio was 0.01/0.1.

Key words: cucumber, regeneration in vitro, hormonal factor, system optimization

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