玉米穗库发育的不同步性与内源激素作用的研究

Unsynchronism of the Development of Ear Sinks and Effects of Endogenous Hormones in Maize

以半多育型杂交种农大高光效 1号和单育型杂交种农大 0 6 38为材料 ,研究了玉米不同穗库在穗分化进程、穗生长、内源激素等方面的差异。结果表明 ,2种育型玉米穗库间的生长发育均存在着不同步性 ,尤其在性器官分化起始时间和持续时间上优势穗库和弱势穗库存在着明显的差异 ,无论单育型或多育型玉米第 1果穗进入该期的时间早 ,且持续时间长 ;在穗长、穗鲜重、穗体积的增长上 ,单育型杂交种第 1果穗比第 2、第 3果穗也具有明显的优势 ,而半多育型品种各穗库间在穗分化阶段这 3个指标上虽有差异 ,但差异均小于单育型杂交种。研究还表明 IAA,GA3 和 ABA在库位优势和穗库发育的不同步性中起着重要的调节作用 ,在穗库生长发育进程中优势穗库的 IAA,GA3 含量明显高于弱势穗库 ,而 ABA含量的变化正好与此相反 ;激素间的平衡在穗库发育中也起着重要的调节作用 ,优势穗库具有较高的 IAA/ ABA和 GA3 / ABA值。由此认为 ,玉米穗库间竞争能力的大小或最终能否成穗与其穗分化阶段所奠定的生长发育基础和内源激素水平 (尤其是IAA)

Nongda Gaoguangxiao 1 (semi prolific hybrid ) and Nongda 0638 (non prolific hybrid) were used to study the process of differentiation, development and endogenous hormones in different ears in maize. The results showed that in both varieties the development of different ear sinks was not synchronous. Especially in the initiation and duration of sexual organ differentiation significant difference existed between the superior and inferior ears. The initiation of sexual organ differentiation was earlier and the duration was longer in the first ear than in the second and third one. And the first ear was larger in the ear length, fresh weight and volume than the second and third one, but the difference was more significant in the non^prolific hybrid than in the semiprolific hybrid. The results also showed that 1AA, GA 3 and ABA strongly affected the unsynchronism of the ear development. The concentration of IAA and GA 3 was higher and ABA lower in the superior ear sink in the whole process. It indicated that the competitive ability of maize ear sinks was related to the developmental basis in the ear differentiation and the concentration of endogenous hormones (especially IAA).