不同环境下籼型杂交稻穗干物质重的发育遗传分析

选用穗干物质重性状差异较大的 4个籼型不育系 (A)和相应的保持系 (B)以及 5个籼型恢复系(R) ,按不完全双列杂交设计 (4× 5 ) ,配成一套亲本和F12个世代的遗传群体 .采用包括基因型×环境互作的加性 显性发育遗传模型 ,分析了两年的籼型杂交稻不同发育时期穗干物质重的遗传表现 .结果表明 ,穗干物质重的发育全过程均受到遗传主效应和基因型与环境互作效应的控制 .在穗干物质重发育的前、中期 (15d前 )主要由显性效应控制 ,显性效应基因的表达量最大 ,环境因素的正向影响也较明显 ,可通过采取适当的栽培管理措施为稻穗发育创造良好的环境条件 ,促进杂种优势潜力的充分发挥 ;在发育的中后期 (15d后 )加性效应转为主要作用 ,加性效应基因的表达也呈最活跃状态 ,这一时期对穗重进行遗传选择会获得较好的遗传进度 .

Developmental genetic analysis of panicle dry weight of indica hybrid rice Oryza sativa under different environmental conditions

Four indica sterile lines (A) and corresponding maintainer lines (B) as well as five indica restorer lines, which varied in panicle dry weight, were used to create genetic populations of two generations according to incomplete diallel cross design (4 x 5). Analysis on panicle dry weight at different developmental stages based on tow-years experimental data was conducted by using additive-dominant developmental genetic models with genotype effects and genotype x environment interaction effects. The results showed that panicle dry weight was controlled by both genetic main effects and genotype x environment interaction effects in the whole developmental process. During the early-middle developmental periods (15 days after flowering), panicle dry weight was mainly governed by dominant effects, and dominant genes expressed with large amount. The meanwhile, positive effects produced by environmental factors appeared to be significant. Proper cultivation measure to create good external environment conditions for rice panicle was helpful to promote the expression of heterosis potential completely. Within the middle-late developmental periods (from the fifteenth day to the thirtieth days after flowering), additive effects played major role, and its genes expresed in the most active state. Genetic selection for panicle conducted in this period was expected to gain better genetic advancement.