用SSR标记揭示部分烤烟种质资源的遗传差异

Accessment of Genetic Difference among Some Flue-cured Tobacco Germplasms Using SSR Markers

【目的】利用SSR分子标记技术,分析59份烤烟种质的遗传差异。【方法】利用分布于烟草基因组21条连锁群上的56对SSR引物,揭示59份烤烟种质的遗传差异。【结果】共检测到241个多态性位点数,每对引物可检测到的多态性位点数为1~9个,平均为4.3个;引物的多态信息含量(PIC)为0.532~0.931,平均为0.793;中国烤烟种质间平均遗传距离最大为0.239;中国地方品种间的平均遗传距离最大为0.289。59份烤烟种质间的遗传距离变化范围为0.029~0.419,平均遗传距离为0.214。聚类分析表明,在L_1(GD=0.13)处可将59份烤烟种质划分为1个大类群、2个小类群和1个由单一烤烟种质形成的独立个类;在L_2(GD=0.09)处可将54份烤烟种质进一步划分为2个大类群、3个小类群和9个由单一烤烟种质形成的独立个类。【结果】59份烤烟种质资源间遗传差异相对较小,中国种质间的遗传差异均大于美国和津巴布韦种质间的遗传差异;地方品种间的遗传差异大于选育品种间的遗传差异。

【Objective】59 flue-cured tobacco varieties were analyzed by SSR technique to study theirgenetic difference.【Method】In order to investigate the genetic difference of flue-cured tobacco germp-lasms, 59 flue-cured tobacco varieties were analyzed by 56 SSR primer pairs distributed on 21 linkagegroups.【Result】A total of 241 polymorphic loci were amplified using the 56 SSR primer pairs, and thenumber of polymorphic loci detected by each SSR primer ranged from 1 to9, with 4.3 polymorphic lociper marker on average. The PIC （polymorphism information content） values of primers ranged from 0.532to 0.931, an average of 0.793. Genetic distance（GD）among the 59 flue-cured tobacco germplasmsranged from 0.029 to 0.419, with an average of 0.214. The maximum genetic distance among China flue-cured tobacco germplasms is 0.239. The maximum genetic distance among China landraces is 0.289. Theresult of cluster analysis based on SSR markers showed that 59 varieties could be clustered intoa biggroup, two small groups and an independent classes formed bya single flue-cured tobacco germplasm atthe level of GD=0.13; 54 varieties could be further classified into two big groups, three small groups andnine separate classes formed by a single flue-cured tobacco germplasm.【Conclusion】The geneticdifferences among 59 flue -cured tobacco germplasms were relatively small; The genetic differencesamong China germplasms was greater than the genetic differences among the America and Zimbabwegermplasms; The genetic differences among landraces were greater than the genetic differences amongvarieties.