RAPD-based assessment of genetic diversity in cotton (Gossypium hirsutum L.) race stock accessions

Twenty-five cotton (Gossypium hirsutum) accessions from Africa, Australia, USA and India were sUbjected to RAPD analysis using 86 random oligonuceotide primers. The major objectives of the study were to study the extent of genetic variation and find out the duplicates if any. Sixty three primers detected polymorphism. A total ot 296 DNA fragments were generated by the 63 primers, of which 113 were polymorphic. The accessions revealed genetic divergence ranging from 0.13 to 0.33 among themselves. RAPD analysis using SIMQUAL-Dice Coefficient of NTSYS-pc showed that the 25 accessions could be split into 2 groups of 24 and 1 accessions at 67% similarity. The first group of 24 accessions could be divided into cluster A consisting of 20 accessions and cluster 8 consisting of 4 accessions. Accessions AC 53 and AR 43 were found to be 100 percent similar based on molecular analysis, but could not be considered as duplicate, because of very low reproducibility of the RAPD markers.