玉米籽粒性状的遗传模型研究

用１０个遗传上和籽粒形态性状上具有差异的玉米自交系，依多种可能的交配方法获得亲本Ｐ１、Ｐ２、Ｆ１（Ｐ１× Ｐ２）、Ｆ２、Ｂ１（Ｆ１×Ｐ１）、Ｂ２（Ｆ１× Ｐ２）及其相应反交ＲＦ１、ＲＦ２、ＲＢ１、ＲＢ２共１０个种子世代。种植２年。依广义遗传模型建立包括种子胚乳加性、胚乳显性、母体加性、母体显性和细胞质效应的遗传模型，运用种子数量性状的精细鉴别法［１］和混合模型分析法［２，３］，对粒长、粒宽、粒长宽比、粒厚及百粒重作了性状表达遗传机制的鉴别与探讨。单个组合的遗传模型精细测验表明，５个籽粒性状的遗传主要受母体显性和胚乳基因型（包括加性和灵性）的控制，一个组合的粒宽、粒厚和百粒重上还检测到细胞质效应。对２５对 Ｆ１正反交组合世代均值依ＭＩＮＱＵＥ法分析的结果表明，５个籽粒性状的遗传方差中，母体遗传方差占６０％以上，胚乳基因型方差低于４０％，粒长和百粒重还有细胞质效应，约占１０％～３０％。可见，籽粒性状的遗传特点是受多套遗传系统控制，其中以母体基因型的作用最大。

Study of Genetic Models of Maize Kernel Traits

Two sets of NCII mating design including 21 different maize inbreds were used to study the genetic models of five maize kernel trait-kernel length, width, ratio of kernel length and width, kernel thickness and weight per 100 kernels. Ten generations including P1, P2, F1, F2, B1, B2 and their reciprocal crosses RF1, RF2, RB1, RB2, were obtained. Three years. data were obtained and analyzed using mainly two methods: (1) precision identification for single cross and (2) mixed liner model MINQUE approach for diallel design. Method 1 showed that kernel traits were primarily controlled by maternal dominance, endosperm additive and dominance effect (maternal dominance > endosperm additive > endosperm dominance). Cytoplasmic effect was detected in one of the two crosses studied. Method 2 revealed that in the total variance of kernel traits, maternal genotypic effect contributed more than 60%, endosperm genotypic effect contributed less than 40%. Cytoplasmic effect only existed in kernel length and 100 kernel weighs with the range of 10% to 30%. The results indicated that kernel genetic Performance was quite largely controlled by maternal genotypic effect.