大白菜裂球性状的遗传与RAPD标记

Inheritance and RAPD Marker of Head-splitting Trait in Chinese Cabbage

以有裂球现象的杂交一代大白菜单株自交构建的F2群体为试材,研究了大白菜裂球性状的遗传规律及其分子标记。调查统计分析表明:延长生育期20d为大白菜裂球性状的最佳分析时期,其F2群体中不裂球与裂球植株符合3∶1分离比例,说明裂球性状是受1对隐性主基因控制的,同时发现分离后代单株间裂球的速度和程度存在差异,说明裂球性状还受到微效基因和环境条件的影响。同时以06J31×92S24产生的F2群体为材料,采用BSA法进行裂球性状RAPD标记,从600个随机引物中筛选出1个与裂球基因紧密连锁的RAPD标记S15-222。连锁分析发现,标记S15-222与裂球基因间的遗传距离为8.876cM,可用于大白菜耐裂球材料的分子标记辅助选择。

A F2 population from a single plant with obvious heading-splitting hybrid in Chinese cabbage 〔Brassica campestris L. ssp. pekinensis（Lour）Olsson〕, was applied to analyze the inheritance of head-splitting trait and to screen linkage molecular marker. The result showed that the best way for surveying head-splitting was delaying plant ripeness for 20 days. And the separated proportion of no-spliting head to splitting head is fitted to 3∶1, which means that at least there is a major recessive gene controlling the trait. In addition,minor genes and environment can also modify the head splitting degree and speed. In the meantime, the genomic DNA extracted from single plant of F2, 06J31 and 92S24 were used as template to PCR amplification. Primer S15 was selected from 600 random primers and the marker S15-222 was tightly linked with the gene of head-splitting trait. The linkage analysis showed that the distance between the marker S15-222 and head-splitting gene was 8.876 cM, which is useful to MAS of splitting-resistance in Chinese cabbage.