激素对白菜GMS系不同育性外植体再生植株的影响

 以白菜核雄性不育两用系的可育株和不育株带有子房及花柄的花托为外植体, 比较了不同育性外植体再生体系的异同; 并结合内源激素含量测定, 探讨了内源激素、外源植物生长调节剂间的相互作用对不同育性外植体再生的影响。结果表明: 不育和可育再生体系所需的最佳NAA浓度分别为0.2 mg·L^-1和0.1 mg·L ^-1; 在最适的NAA浓度下补给不同浓度的6-BA, 不育外植体不定芽诱导率差异不大, 而可育外植体不定芽诱导率则随62BA浓度的增加表现不规律的变化。不同育性的外植体内源激素含量测定结果表明, 可育外植体内源GA₃、IAA和ZT含量分别比不育外植体高出37.8%、28.0%和224.9%; ABA含量则是不育外植体比可育外植体高出20.4%。花柄及花托再生得到的不定芽在不继代或继代次数少的情况下生根培养时高频现蕾, 生根率极低; 随着继代培养时间的延长, 生殖生长趋势逐渐减弱, 生根率明显提高。

Effect of Hormones on the Regeneration of Different Explants of GMS Line in Brassica campestris L. ssp. chinensis

Receptacles with ovary and pedicel used as explants, the regeneration systems of different fertility explants of genic recessive male sterility A/B lines in Chinese cabbage-pak-choi (Brassica campestris L. ssp. chinensis Makino) were compared. Moreover, itwas analysed that the effect on different fertility explants regeneration of interaction between endogenous hormone of exp lant itself and exogenous app lication. Results showed that the best exogenous NAA concentrations for adventitious shoots induction of the sterile and the fertile explantswere 0.2 mg·L ^{- 1} and 0.1 mg·L ^{- 1} , respectively. With the optimal NAA concentrations, shoot induction rate of sterile explants was not significantly affected by 6-BA, however, that of fertile showed erratically change with different 62BA concentration. The result of endogenous hormone determination showed that the endogenous contents of GA₃ , IAA and ZT in fertile explants were 37.8% , 28.0% and 224.9% higher than in that of the fertile, but ABA content is sterile exp lantswas 20;4% higher than that of the fertile. The shoots regenerated from this kind of floral explants showed high frequency bolting rate without subculture or with few times subculture. But with the times of subculture increasing, the tendency of rep roductive growth declined whereas the rooting rate enhanced significantly.