吉林省新育成几个BT型不育系开花习性研究

Research on the Flowering Habit of Several BT-type Rice Male Sterile Lines Bred in Jilin Province

[目的]了解吉林省新育成BT型不育系开花习性,为提高杂交稻制种产量提供基础数据。[方法]以吉林最新育成的三系粳稻不育系为材料,田间观察不育系的开花历期、开花动态、柱头外露率和异交结实率等开花习性。[结果]6个不育系的开花习性可以分为2类,A1、A2和A3可以分为一组,即始花时间早,终花时间也较早,花期集中,开花持续时间只有3h;开花高峰集中在11:00～11:30,午前花率很高,平均为88.3%,最高达到了93.8%。其他3个不育系分为另一组,始花时间较晚,终花时间也晚,开花时间长,开花高峰晚,基本都集中在12:30～13:00,午前花率很低,平均在46.0%,最高为59.0%。不育系的异交结实率和柱头外露率、开颖时间呈极显著的正相关,相关系数为0.996和0.955。[结论]选育柱头外露率高、开颖时间长的不育系可以提高制种产量。

[Objective] The basic data for the improvement of the hybrid rice seed production was provided through the understanding of the flowering habits of new BT-type male sterile line bred in Jilin.[Method] The latest CMS line of three-line japonica rice bred in Jilin being taken as the experimental material,the flowering duration,flowering dynamics,exposed rate of stigma and out-crossing rate and other flowering habits were observed in field.[Results] The flowering behavior of 6 rice sterile lines could be divided into two types,A1,A2 and A3 were classified into Group One,which was with earlier in both initial and final flowering time,concentrated flowering time,flowering duration of only 3 hours,flowering peak concentrated from 11：00 to 11：30,and higher flowering rate before noon with an average of 88.3% and max rate of up to 93.8%.The other three male sterile lines were classified into GroupTwo,which was with later in both initial and final flowering time,long flowering duration,later in peak flowering time basically concentrated from 12：30 to 13：00,and low flowering rate before noon with average of 46.0% and max rate of only 59.0%.There was a significant positive correlation between the outcrossing rate and the exposed rate of stigma,glume-opening duration,which correlation coefficient was 0.996 and 0.955,respectively.[Conclusion] The sterile line breeding with high exposed rate of stigma and longer glume-opening duration can improve hybrid rice seeds production.