烤烟种质资源SSR核心引物的筛选及验证

摘要

The purpose of our study is screening out suitable SSR core primers which can accurately evaluate germplasm genetic diversity and genetic relationship of flue-cured tobacco. In this study, 2317 pairs of SSR primers distributed in 24 chromosomes were initially screened on 5 flue-cured tobacco cultivars with distant genetic relationship, and 70 pairs of primers were screened out. Then 20 flue-cured tobacco cultivars with different geographical origins were chosen to screen the initial selected primers. Finally, a total of 24 pairs of SSR core primers were identified. The genetic diversity of 20 flue-cured tobacco cultivars was nalyzed using these core markers. As a result, 85 polymorphism bands were acquired. The average PIC (Polymorphism information content) value is 0.52 and the mean number of alleles detected for each locus was 3.54. These 20 tobacco cultivars were conducted on both genetic diversity analysis and PCoA (Principal Coordinate Analysis) to demonstrate the effectiveness of this 24 core primers. These two methods exhibited similar phylogenesis among the tested cultivars and the results of molecular clustering largely agreed with the pedigree relationship. The results showed that the core primers were effective and accurate, and could be applied to flue-cured germplasm identification and genetic diversity study in tobacco.%为筛选到适合烤烟品种利用的核心引物，准确评价烟草种质资源遗传多样性和亲缘关系，利用5份遗传差异明显的烤烟种质对分布于烟草24条连锁群上的2317对SSR引物进行初步筛选，筛选出70对引物。再利用20份不同地理来源的烤烟种质对初筛引物进行复筛，最终确定24对核心引物。利用核心引物对20份烤烟种质进行遗传多样性分析，共得到85个多态性位点，平均PIC值为0.52，平均等位位点数为3.54。同时对这20份烤烟种质进行聚类分析和主坐标分析，验证24对核心引物的有效性。结果显示，两种研究方法结论一致，与种质亲缘关系吻合度较高。表明该 SSR 核心引物体系准确有效，可以适用于烤烟种质资源鉴定和遗传多样性分析。