ABA与GA_3对黄瓜离体子叶和石刁柏茎生根的影响

较高比值的内源ABA/GA_S有利于黄瓜黄化子叶和石刁柏茎不定根的发生。外源ABA具有增加组织内ABA含量并降低GA_S含量而促进生根的作用,而外源GA_S则与ABA效果相反。外源GA_S浓度为10~(-5)mol/L时,外源ABA对黄瓜子叶生根的诱导被明显抑制。子叶内GA_S含量较高的黄瓜1101品系其父本发根能力明显低于母本。ABA与GA_3对不定根发生的调控作用在黄瓜子叶离体培养的第一天最明显。

Effects of ABA and GA_3 on Root Initiation of Cucumber Gotyledon and Asparagus Shoot in Vitro

Effects of ABA and GA_3 on the rooting of cucumber cotyledon and asparagus shoot were studied. The results indicated that exogenous ABA (around 10~(-7) mol/L) promoted root initiation, but GA_3 inhibited it (Fig. 1, 5. Table 2). Radioimmunoassay (~3H) showed that exogenous ABA increased the content of endogenous ABA and decreased that of GA_S in tissue. The ratio of ABA/GA_S in cucumber cotyledon and asparagus shoot induced by ABA (10~(-7) mol/L) respectively was 2.44 and 5.31 times of control (Fig. 4, Table 2). In addition, higher level of endogenous GA_S inhibited rooting, the rooting percentage of 1101 monoecious cotyledon involving higher content of GA_S was markedly smaller than that of 1101 gynoecious (Table 1). In general, a relatively higher ratio of ABA/GA_S in tissue was beneficial to the root initiation. The roles of ABA and GA_3 were most obvious at the first day of root initiation of cucumber cotyledon. The interaction of ABA and GA_3 was discussed and the balance of endogenous plant hormones in the process of rooting was analyzed.