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.