水稻(Oryza sativa L.)亚种间杂交穗部性状的双列分析

采用6×6没有反交的完全双列杂交,对亚种间杂交穗部性状的遗传和基因作用以及配合力进行了研究。结果表明,粒长、粒宽、长宽比和粒重为不完全显性,遗传方差中以加性效应为主;穗长、二次支梗数、穗粒数为超显性,显性效应大于加性效应;一次支梗数表现有明显的上位性效应。狭义遗传力的排列顺序为粒宽>长宽比>千粒重>粒长>穗长>穗粒数>二次支梗数。二次支梗数和穗粒数具有相似的遗传基础,其余性状的基因系统具有相对的独立性。8EC1936对所有考察性状皆含有较多显性基因,而02428隐性基因偏多。约有1组显示显性的基因控制籽粒长宽比。穗长、千粒重、一次支梗数、二次支梗数和穗粒数的一般配合力和特殊配合力皆达极显著水平,粒长、粒宽、长宽比仅一般配合力达极显著。Lemont和02428对穗粒数及其相关性状的一般和特殊配合力俱佳;而对增加粒重和获得理想的籽粒形状8EC1936.CA529和矮64、Lemont是可供选择的亲源。

DIALLEL ANALYSIS IN CHARACTERS IN RELATION TO GRAIN AND PANICLE OF RICE INVOLVING INTERSUBSPECIFIC HYBRIDIZATION

Studies on inheritance, gene effects and conbining ability were made for characters in relation to grain and panicle in a six—parent diallel set(excluding reciprocals) with Indica 8EC1936 and Peiai 64, Javanica Cpslo 17 and Lemont, and Japonica O2428 and CA529. Grain lenghth, width, lenghth/width and grain weight were expressed as incomplete dominance and predominant addtive gene effect. Panicle lenghth, secondary branch, full spikelet number per panicle showed over dominance and nonadditive gene effect being of predominance. Epistasis was detected for the primary branch. The ranking of narrow—sense heritability was grain width>lenghth/width>grain weight>grain lenghth>panicle lenghth>spikelet nummber per panicle>secondary branch. Secondary branch and spikelt number per panicle bearied the similar genetic basis but independence of gene system did for other characters. 02428 possessed excessive dominant genes and instead 8EC1936 possessed excessive recessive genes for all the characxters examined. Both G. C.A. and S. C. A. were significant at 1% for panicle lenghth, grain weight, primary branch, secondary branch and sipkelet number per panicle. For grain leighth, width, leigth/width G.C.A. was significant at 1%. Lemont, 02428 was the good combiner for spikelet number per panicle and its relevent characters. 8EC1936, CA529 and Peiai64, Lemont were promising parents for increasing grain weight and attaining slender grains, respectively.