应用SRAP与ISSR分析烟草种质资源遗传多样性及遗传演化关系

应用ISSR与SRAP两种分子标记，研究国内外96份烟草种质的遗传多样性及不同栽培类型种质的遗传演化关系。表明烟属种间具有丰富的遗传多样性，种间的遗传相似性(GS)在0.28~0.58之间，遗传分化系数(Gst)为0.83。普通栽培种品种间遗传多样性水平较低，品种间的遗传相似性在0.61~0.99之间，栽培种内的遗传多样性为烤烟>晒晾烟>白肋烟>香料烟。当相似系数在0.67作切割线时，基于2种标记的96份烟草种质资源的聚类结果为，(1)普通烟草栽培品种材料91份聚在同一大类，而黄花烟、黏烟草、浅波烟草、哥西氏烟草、香甜烟草5个种也分别为单独的个类，同普通烟草栽培种类群完全区别开来；(2)从进化上看，烤烟和晒晾烟间的遗传进化关系最近，香料烟和黄花烟之间的亲缘关系较远；普通烟草栽培种中国内外来源的烟草品种亲缘关系极其相近，遗传分化现象甚微；(3)2种分子标记虽然原理不同，但分析结果趋势相近(r=0.68，P=1.000)。

Genetic Diversity and Evolutionary Analysis of Tobacco(Nicotiana tabacum L.) Germplasm Resources Based on ISSR and SRAP Markers

In order to explore on the genetic diversity and genetic evolution among cultivated types and wild species in the genus Nicotiana,96 tobacco accessions from China and abroad were studied with ISSR and SRAP analysis.Both molecular markers revealed high genetic diversity among species of Nicotiana(genetic similarity = 0.28-0.58) and low genetic diversity among 91 cultivated tobacco lines(Genetic Similarity = 0.61-0.99).Genetic differentiation index(GST) among species of Nicotiana was 0.83.The order of genetic diversity index within different cultivated types was cured tobacco>suncured tobacco>burley tobacco>oriental tobacco.When the similarity coefficient was 0.67 as the cutting line,the cluster results of 96 tobacco accessions based on SRAP and ISSR were as follows:(1) UPGMA analysis showed that all 91 culture varieties clustered into one group separating from N.rustica,N.glutinosa,N.repanda,N.gossei,N.suaveolens.(2) The cured tobacco has close genetic relationship with suncured tobacco,and oriental tobacco was far away from N.rustica.There was little genetic differentiation between cultivated tobacco lines from China and those from other countries.(3) The correlation coefficient between genetic distance matrixes based on ISSR and SRAP was 0.68,indicating that the basic results of the two types of markers are consistent.In conclusion,ISSR and SRAP are efficient in generating more accurate information on genetic background,relationship and evolution of tobacco germplasm.The results of this research would be favorable for further practices in tobacco breeding.