水稻雄性核不育系5个抽穗性状的遗传分析

Genetic Analysis of Five Heading Traits of Male Sterile Lines in Rice

不育系的抽穗性状是影响杂交水稻制种产量的重要性状。为改良水稻雄性核不育系抽穗性状提供理论指导,本研究调查了粳型光敏核不育系7001S和籼型光温敏核不育系超818S及其杂交F1、F2群体在湖南常德和海南三亚等2个环境下的5个抽穗相关性状,分析了这5个性状间的相关性,同时利用主基因+多基因混合遗传模型对该5个抽穗相关性状进行分析。结果表明,穗抽出度与穗剑高度差、剑叶长与剑叶宽之间呈极显著正相关;穗剑高度差与剑叶长、剑叶宽呈显著或极显著负相关。除海南三亚环境中的剑叶宽外,其余性状均表现出受2对主基因控制,2对主基因的作用方式因性状而异。穗抽出度、剑叶角度和穗剑高度差3个性状以主基因遗传为主;剑叶长和剑叶宽2个性状以多基因遗传为主。育种中,对于剑叶长和剑叶宽等以多基因遗传为主的性状,可通过聚合杂交的方法在高世代根据育种需要进行选择,而对于穗抽出度、剑叶角度和穗剑高度差等以主基因遗传为主的性状,可通过杂交、回交和系谱选择的方法在低世代进行改良。

Heading traits play an important role in achieving a high yield of hybrid rice seed production. To provide scientific basis for improving the heading traits of male sterile lines in rice, five heading traits of 7001 S(a photo-and thermo-sensitive genic male sterile line of japonica rice, P1) and Chao 818 S(a thermo-sensitive genic male sterile line of indica rice, P2) and their F1, F2 were investigated in two environments of Changde, Hunan and Sanya, Hainan. The analysis was conducted on the correlation among the heading traits and the genetic behavior by the major gene and polygene mixed inheritance models. The results showed that there existed a very significant(P<0.01) positive linear correlation of the panicle exsertion degree(PED) to the height difference between the tips of panicle and flag leaf(DPFT), flag leaf length(FLL) and flag leaf width(FLW);there existed a significant(P<0.05) or very significant negative linear correlation of DPFT to FLL or FLW, respectively. Except for FLW in E2, the others were controlled by two major genes in E1 and E2, but the interaction of two major genes varied with the trait. The traits of PED, flag leaf angle(FLA) and DPFT were mainly controlled by major genes while FLL and FLW were mainly governed by polygenes. In breeding, FLL and FLW can be selected by polymeric hybridization in higher generations while PED, FLA and DPFT can be improved by means of hybridization, backcross and pedigree selection in lower generations.