期 刊 ：植物遗传资源学报 2016年 17卷 4期
Keywords:flue-cured tobacco(Nicotiana tabacum), aroma components, SSR, association analysis,
摘 要 ：了解烤烟品种的遗传多样性，寻找与烤烟致香物质含量关联的分子标记，挖掘高致香物质含量的优异等位变异与种质，对香气品质分子标记辅助育种具有重要意义。本研究检测了山东和四川两生态区60份烤烟种质中76种致香物质的含量；筛选覆盖全基因组的1914个SSR标记，利用得到的390对多态性引物扩增供试群体。用基于Nei’s（1983）遗传距离的邻接法（Neighor-joining, NJ）进行聚类分析。在分析群体结构的基础上，利用混合线性模型进行关联分析，并进一步发掘极显著关联标记的优异等位变异和种质。结果检测到928个等位变异，平均每个位点2.38个等位变异，变化范围为2-5个。PIC值的变化范围分别为0.141-0.733，平均值0.332。这说明供试群体遗传多样性较丰富。聚类分析将该群体划分为两个亚群，划分结果体现了烤烟品种间的亲缘关系；群体结构分析与聚类结果基本一致。关联分析结果显示：在P＜0.05水平下，共有56个SSR标记位点与41种致香物质同时在两个生态区显著关联。P＜0.01水平下，共5个标记与6个性状在两个生态区极显著关联，6种致香物质为草酸、肉豆蔻酸、2，4-庚二烯醛、芳樟醇、a-松油醇和gamma-壬内酯，关联标记分别为PT50662、PT60191、PT52263、PT60597、PT60597和PT52722。关联位点表型解释率为12.54%-42.20%。进一步分析发掘了14种致香物质的优异等位变异,并筛选出含增效等位变异较多的种质：净叶黄、抗9201、单育二号、满屋香、金星6007、秦烟95等。这对香气品质分子标记辅助选择育种以及亲本材料选配等奠定了基础。
Abstract:The objective of this study is to understand genetic diversity about flue-cured tobacco, find valuable molecular markers associated with aroma constituents, and excavate excellent alleles and germplasms, which is beneficial for the study of molecular marker assisted breeding of tobacco aroma quality. In this study, 76 kinds of aroma constituents were identified from 60 kinds of flue-cured tobacco germplasms from two areas. Test population were amplificated using 390 pairs of polymorphic primers screened from 1914 SSR markers covering the whole genome. Nei’s genetic distance and neighbour-joining were adoped in cluster analysis. Based on the detection of population structure, we used the mixed linear models to analysis the relations between phenotype and genotype and finded some excellent alleles and germplasms. The 390 pairs of polymorphic primers displayed 928 allelic variation, the average of polymorphism information content (PIC) was 0.332, which ranged from 0.141-0.733, which showed high genetic diversity. The test group was dicided into two subgroups based on Nei’s genetic distance, which reflected the genetic relationship among tobacco cultivars. Genetic structure analysis mainly consist with Nei’s genetic distance analysis. Correlation analysis showed that: at the level of P < 0.05, 41 kinds of aroma constituents were associated with 56 kinds of SSR markers. At the level of P <0.01, there were 5 markers significantly associated with 6 kinds of aroma constituents including oxalic acid, myristate acid, a-terpineol, linalool, 2,4-Heptadienal and gamma-amylbutyrolactone, the percentage of phenotypic variation explained ranged from 12.54%-42.20%. Besides, excellent alleles about fourteen aroma constituents were finded, future study obtained some germplasms with more positive alleles: Jingyehuang, 9201, Danyu 2, Manwuxiang, Jinxing6007, Qinyan 95, et al. These results may provide useful information for molecular marker assisted breeding in tobacco quality breeding and screening of parents.