-

In this study, Random Amplified Polymorphic DNA (RAPD) analysis was used to investigate the polymorphisms of upland cotton genotypes. Twenty six genotypes were analyzed with 90 random decamer primers using the Polymerase Chain Reaction (PCR). Twenty one primers detected polymorphism in all the 26 cotton genotypes. A total of 237 bands were amplified, 219 of which (92.4%) were polymorphic. Thirteen primers, clearly polymorphic, were used to estimate the genetic distances between genotypes. Cluster analysis by unweighted pair group method of arithmetic means (UPGMA), after multivariate analysis using Jaccard's similarity coefficients, showed that 26 genotypes could be placed in six groups. Similarity matrix data revealed that genotypes 82203-189 and Siokra-324 are 10.4% similar while
Early Mutagenesis and Bakhtegan are 43.6% similar.
The coefficient of
similarity of most of the other genotypes ranges between 15 and 35%. Results indicated a genetic relationship between genotypes of different origins including American and control Sahel cultivar. This relationship was probably due to similarity of the center of origin of these genotypes. In general, results
indicated that the RAPD analysis is a powerful tool in detecting the genetic relationships between cotton genotypes.