甘蓝型冬油菜抗寒性评价及遗传多样性分析

针对不同品种甘蓝型冬油菜抗寒性和遗传多样性存在差异等特点，于2021年采用随机区组设计，结合系统聚类分析法及SSR标记对32份甘肃省生产应用甘蓝型冬油菜与9份陕西中部及江苏省现推广应用甘蓝型冬油菜品种的越冬率及春化特性差异和遗传多样性进行分析，探究其抗寒性差异,分析品种间遗传多样性及亲缘关系。结果表明：甘肃省生产应用甘蓝型冬油菜越冬率高于80%，陕西中部及江苏省甘蓝型冬油菜品种越冬率均小于25%，且抗寒性强弱差异明显；根据春化率高低，参试材料可分为强冬性、冬性、半冬性、弱冬性等4个级别；强冬性材料未现蕾的植株占比高，春播后难以抽薹现蕾进入生殖生长，加权平均薹高随之偏低，抗寒性强；春化率越高，成熟期的加权平均株高越高且抗性越弱，越冬率与春化率呈负相关关系；筛选出的98对多态性高的引物组合共扩增出976个总位点,其中多态性条带750个,多态位点比率达72%,说明其分子遗传水平上的多态性丰富度高，陕西中部及江苏省甘蓝型冬油菜遗传多样性整体高于甘肃省生产应用甘蓝型冬油菜；通过聚类分析，可将甘蓝型冬油菜划分为9类；根据群体遗传结构分析及主成分分析可分为3大类，与抗寒性分类趋于一致。研究成果有望为鉴别甘蓝型冬油菜品种、构建指纹图谱及选择不同生态区适宜品种等研究奠定基础。

Cold tolerance evaluation and genetic diversity analysis of winter Brassica napus

In view of the differences in cold resistance and genetic diversity among different varieties of Brassica napus, a randomized block design was adopted in 2021. The differences in overwintering rate, vernalization characteristics and genetic diversity between 32 varieties of Brassica napus in Gansu Province and 9 varieties of Brassica napus in central Shaanxi and Jiangsu Province were analyzed. The systematic cluster analysis and SSR markers were used to explore the differences in cold resistance. The results showed that the overwintering rate of winter Brassica napus varieties in Gansu Province was higher than 80%, and the overwintering rate of winter Brassica napus varieties in central Shaanxi and Jiangsu areas were less than 25% with the significant differences in cold resistance. According to the vernalization rate, the tested materials were divided into four levels: strong winter, winter, semi winter and weak winter. The proportion of plants without buds in strong winter materials was high. It was difficult to bolt and bud into reproductive growth after spring sowing. The weighted average bolt height was low, which had strong cold resistance. The higher the vernalization rate, the higher the weighted average plant height at maturity and the weaker the resistance. The overwintering rate was negatively correlated with the vernalization rate. A total of 976 loci were amplified by 98 pairs of primer combinations with high polymorphism, of which 750 were polymorphic bands, and the ratio of polymorphic loci was 72%, indicating that the polymorphism richness at the molecular genetic level was high. The genetic diversity of winter Brassica napus in central Shaanxi and Jiangsu areas was higher than that of winter Brassica napus in Gansu Province. Through cluster analysis, winter Brassica napus were divided into 9 categories. According to the analysis of population genetic structure and principal component analysis, it was divided into three categories, which were consistent with the classification of cold resistance. The research results could lay a foundation for the further study of variety identification, fingerprint construction and selection of suitable varieties in different ecological areas of Brassica napus.