中国3大主产棉区棉花品种遗传多样性的RAPD及其与农艺性状关系的研究

 选择我国３大主产棉区不同年代有代表性的３０个陆地棉棉花品种，利用ＲＡＰＤ标记进行棉花品种之间分子标记遗传差异的研究。利用 Ｊａｃｃａｒｄ遗传相似系数计算了 ３０个品种的ＲＡＰＤ数据的遗传距离矩阵，按ＵＰＧ－ＭＡ方法进行聚类，发现３０个棉花品种之间的遗传距离在０．０５～１．５８之间。聚类分析表明，３０个棉花品种可分为３组，品种间的遗传关系与品种自身的系谱有关，大多数品种的遗传基础比较狭窄。同时，１９９９年的田间试验调查了３０个品种的１５个农艺性状。并对农艺性状数据和ＲＡＰＤ数据形成的树状图进行了初步比较，二者的相关系数为０．７６，达显著水平，并且二者获得的聚类结果是相似的，这一研究的遗传距离和遗传相似系数为育种者进行亲本选择和品种遗传变异评价提供了理论依据。

Genetic Diversity Analysis of Representative Elite Cotton Varieties in Three Main Cotton Regions in China by RAPD and Its Relation with Agronomic Characteristics

Thirty varieties belonging to Gossypium hirsutum L. were analyzed with 25 random decamer primers filtered from 130 decamer primers using the random amplified polymorphic DNA procedure (RAPD). Cluster analysis by the unweighted pair group method of arithmetic means(UPGMA) showed that 30 varieties could be placed in three groups with genetic distance from 0. 05 to 1. 58. The analysis re- vealed that the intervarietal genetic relationships of several varieties was related to their pedgree of the par- ent and most of the varieties had a narrow genetic base. Meanwhile genetic diversity of 30 varieties was in- vestigated at phenotypic level with stable and relatively high heritable agronomic characters. Fifteen agro- nomic traits were measured on the genotypes in field experimental in 1999. Dendrograms were generated for genetic distance from the RAPDs and mean taxonomic distance from the agronomic traits data. Classifi- cation of all genotypes based on the two methods gave similar results with a correlation of 0. 76 between the genetic distance and taxonomic distance. This experiment demonstrated that RAPD analysis could reli- ably determine genetic relationships within a diverse array of cotton varieties. Genetic relationships and the genetic similarity obtained from the analysis in present study can help in the selection of parents for breed- ing purposes and be used for evaluation of varieties genetic diversity.