汕优63及其亲本穗发芽若干特性初探

Characteristics of the Pre—harvest Sprouting of hybrid rice“Shanyou 63”and Its parents

1989～1991年对杂交水稻汕优63制、繁种田的穗发芽研究表明,除恢复系明恢63的穗发芽率低于5%外,其余包括不育系珍汕97A、保持系珍汕97B和杂交种汕优63的穗发芽均高于20%,后3个品种的穗发芽均随着籽粒的发育而逐渐提高。至始穗后24天出现一急剧上升时期,这种穗发芽的田间变化趋势与品种本身潜在发芽率的变化一致,杂交稻制繁种过程中的穗发芽主要与保持系的胎萌特性有关。GA可提高结实率50%,同时也促进了穗发芽(为对照2倍),在被调查品种中裂谷率与穗发芽的程度并非是简单的正比关系。

The investigations in 1989—1991 on the hybrid rice“shanyou 63”in production and malesterile line multiplication fields revealed the facts as follows:First,only the fertility restore line(Minghui 63)percentage of pre—harvest sprouting is lower than 5%,and the rests (including themole sterile line zhengshan 97A,the maintainer line zhengshan 97B and the hybrid shanyou 63 ofzhenshan 97A×Minghui 63) up to higher than 20%;secound,the level of pre—harvest sproutingof the three varieties rose gradually with the grain developing,but abruptly after 24th days ofheading,which was well concordant with the characteristic changes of the germination protenialof the corresponding varieties.It was genatically reduced that the viviparity in the system of pro-duation and multiplication of hybrid rice seeds is mainly controled by the maintainer line withthe high germination protenial.Fuhermore,the application of the hormone GAs could promotethe higher setting percentage (about 150% of the cantrol),and stimulate the level of pre—har-vest sprouting up to twice as much as the control simultaneously.however,there was a complict-ed rather than a simply direct proportional relation betweem the ration of the deft hull grainsand the percentage of the germination on the ears of the varieties investigated.