白菜抽薹相关性状遗传分析

研究与白菜抽薹相关性状的遗传特性，为白菜类作物晚抽薹育种应用提供理论依据。试验以抽薹指数、开花时间和薹长5 cm时间分别作为抽薹早晚的评价标准，应用植物数量性状主基因+多基因混合遗传模型，对晚抽薹大白菜高代自交不亲和系(P1)和易抽薹欧洲白菜型油菜自交系(P2)及杂交所获得的F1、B1、B2和F2各世代群体进行联合遗传分析。结果表明，抽薹指数性状和薹长5 cm时间性状均受2对加性-显性-上位性主基因控制（B-1模型），开花时间性状受1对加性-显性主基因+加性-显性-上位性多基因控制（D模型）。与抽薹相关的3个性状各分离世代(B1、B2、F2)均未检测到多基因遗传，其主基因遗传率分别为抽薹指数96.22%(B1)、93.33%(B2)、93.55%(F2)；开花时间70.68%(B1)、70.68%(B2)、70.64% (F2)；薹长5 cm时间79.44%(B1)、79.55%(B2)、79.38%(F2)，环境条件对白菜抽薹性状影响较大。由此可知，对白菜抽薹性状的遗传改良应以主基因为主，适宜在早期世代进行选择并注意环境条件影响。

Inheritance Analysis of Bolting Correlated Traits Using Mixed Major Gene Plus Polygene Model in Brassica rapa

The mixed major-gene plus polygene inheritance model was used to analyze the inheritance of bolting correlated traits in Brassica rapa, which will provide useful information for breeding a late bolting or bolting-resistant cultivars of Brassica rapa. Three phenotypic measurements, bolting index, flowering time, days to 5 cm elongated stalk, respectively, were used for inheritance analysis with six generations of P1 (bolting resistant inbreed line) and P2 (vernalization independent type) and their F1, B1, B2 and F2. The results showed that the two traits, bolting index and days to 5 cm elongated stalk, both were controlled by two major genes with additive-dominance-epistatic effects (B-1 model) in hybrid. The flowering time was controlled by one major gene with additive-dominance effects plus poly-genes with additive-dominance-epistatic effects (D model). The heritability of the major genes in B1, B2 and F2 were 96.22%, 93.33%, 93.55% for bolting index, 70.68%, 70.68%, 70.64% for flowering time, 79.44%, 79.55%, 79.38% for days to 5-cm elongated stalk, respectively. But no polygene heritability was checked in B1, B2 and F2 segregating generations. It indicated that the bolting trait in Brassica rapa was controlled by one or tow major genes. This implied that in the genetic improvement for bolting resistant trait major gene is a main factor. It is fit for early selection and environment factor should also be mentioned.