烟草种质资源遗传多样性的IRAP和ISSR标记比较分析

采用IRAP和ISSR两种分子标记方法，对国内外28份烟草种质资源进行聚类分析，并对两种方法的结果予以比较。结果如下：（1）用IRAP方法对供试材料进行PCR扩增，共得到214条条带，其中187条具有多态性，多态性比率达87．4％。当L1取值0．495时，可将28份材料划分为3个类群；L2取值0．34时，又可将第3类群划分为3个亚类群和3个单一品种组成的独立个类；（2）用ISSR方法进行PCR扩增时，共得到334条条带，其中250条有多态性，多态性比率为75％。当L1取值0．41时，可将28份烟草种质划分为2个类群和2个独立个类Coker176、BaSmaUovina，第一类群（Ⅰ）为来自美国的两个品种RG11和K730，其它24个品种为第二类群（Ⅱ）；（3）IRAP和ISSR两种方法的相关系数为0．823（r0．01=0．478），说明这两种方法的结果高度相关，均可用来进行烟草种质资源遗传多样性的分析。用IRAP方法得到的品种间遗传相异系数（GD）平均为0．423，高于ISSR方法，而且条带更稳定、多态性比率更高，更易揭示不同品种材料的遗传差异。

Comparison and Analysis of IRAP and ISSR Molecular Methods Used for Assessment of Genetic Diversity in Tobacco

The cluster analysis of 28 tobacco accessions was assessed using IRAP and ISSR molecular methods.The results based on these two methods were compared.The results were as follow:(1) 214 bands were produced by IRAP,of which 187 bands were polymorphic,and the percentage of polymorphic bands was 87.4%.The 28 accessions could be classified into three groups at the level of L_1=0.495.The third group could be classified into 3 subgroups and 3 unique types at L_2=0.34.(2) 334 bands were produced by ISSR,of which 250 bands were polymorphic,and the percentage of polymorphic bands was 75%.The 28 tobacco accessions could be classified into two groups and 2 unique types (Coker176,BaSmaUovina) at the level of L_1 =0.41.The first group (Ⅰ) included two accessions from America (RG11 and K730),and other 24 accessions were included in the second class (Ⅱ).(3) The correlation coefficient between IRAP and ISSR analyses was 0.823(r0.01=0.478),which indicated these two methods were both fit for the study of genetic diversity in tobacco.But IRAP technique had higher GD(genetic dissimilarity coefficient),better stability,and higher polymorphic than ISSR method.The genetic diversity and relationship of tobacco germplasm could be distinguished more easily by IRAP.