玉米低磷耐性性状的主基因＋多基因遗传分析

Genetic Analysis of Tolerance to Low-phosphorous Stress in Maize Using Mixed Model of Major Gene Plus Polygene

以玉米缺磷症状叶为指标,应用植物数量性状主基因+多基因混合遗传模型多世代联合分析方法,对1个耐低磷玉米自交系T和2个低磷敏感玉米自交系S1、S2及其组配的杂交、回交群体的6个世代材料进行遗传分析,研究玉米耐低磷性状的遗传机制。结果表明,玉米低磷耐性遗传在2个组合中都是由1对加性+加性-显性多基因控制;主基因遗传率(F2)平均为60.85%和60.29%,多基因遗传率(F2)平均为22.02%和23.47%;T×S1组合的遗传变异占表型变异值为83.79%,T×S2组合的遗传变异占表型变异值为82.34%,表明耐低磷性状以主基因遗传为主。

In order to estimate the genetic model and genetic parameters of maize tolerance to low-phosphorous using the number of leaf with low phosphorous symptom in six generations（P1, P2, F1, BI, B2 and F2） derived from two crosses of T（tolerance to lowphosphorous stress） × S1（sensitivity to low-phosphorous stress） and T ×S2 in maize. The results showed that tolerance to low-phosphorous stress in maize was dominated by one major gene with addi- tive effects plus poly-genes with additive-dominance effects（D-2 model） in two cross. The additive effects of two major genes in two crosses were more powerful than poly-genes. On average, hereditability of major genes was 60.85%, 60.29% in F2 population, and that of poly-genes（h2pg） in F2 population was 22.02%, 23.47%. It indicated that the tolerance to low- phosphorous stress in maize was dominated by major genes. In addition, the genetic vari- ance accounted for 82.34%and 82.34% of the phenotypic variance in each population respectively, indicating high- er hereditability of major genes.