中熟抗病晚粳品种选育中抽穗期的遗传及基因效应分析

本试验选用４个晚粳品种（系）．采用了Ｈａｙｍａｎ和Ｍａｔｈｅｒ法对其双亲本杂交（含回交）组合的抽穗期的世代平均数进行了遗传变异分析及基固效应评估。结果表明：抽穗期呈部分显性或不完全显性表型，其显性方向（早熟或迟熟）则固组合而异。抽穗期的遗传方式符合加性一显性模型；基固的加性效应极显著，而显性效应和上位性效应则皆不显著。在抽穗期的遗传变异中，虽然加性方差和显性方差都存在，但仍以加性遗传方差为主；其狭义遗传率和广义遗传率分别高达７７％和９５％。以有效因子数目估计值推断，至少有一时显性熟期基因起作用。本文就中熟抗病晚粳类型品种选育中生育期的育种选择及熟期与白叶枯病抗病反应的关联性等问题作了初步讨论。

Iuheritance and Gene Effects Analysis of Heading Date in Breeding Late-season Japonica Rice with Mid-maturation Disease-resistant

This study was undertaken to investigate the genetic variation of heading date. and to analyzethe gene effects based on its generation means following Haynian & Mather's method. The inhertance of headingdste was found to be partial or incomplete dominant ,while its direction (earlier/or late-maturing) varied with bi-porental crosses tested. The mode of heading dste quite fitted the additive-dominance model with highly significantadditive gene effects and non-significant dominance and epstotic gene effects. Results also showed that the additivegenetic variance played the lesding role comparing with dominance genetic variance. It can be inferred from the ef-fective factor that there exists at least one poir of bominant genes responsible for the character. A discussion wasmade on the selection and breeding of growing duration and its relationship with resistant reactions to BLB (Bacteri-al leaf blight) in the brerding programme of late-season japonica rice varieties with mid -maturation disease-resis-tant.