GENETIC DIVERSITY STUDIES AMONG COLOURED COTTON GENOTYPES BY USING RAPD MARKERS

Estimation of genetic diversity and the relationship between varieties are valuable sources of cotton breeding. Present study employed 11 colored cottons (10 genotypes belonging to Gossypium hirsutum and one to Gossypium arboreum) and five white-linted genotypes (4 of these belonging to Gossypium hirsutum and one to Gossypium arboreum) collected from different research stations of Pakistan for genetic diversity assessment via RAPDs. Out of 45 decamer randomly sequenced primers applied for RAPD analysis, 25 showed polymorphism. All of the 25 primers produced 205 fragments, out of which 144 were polymorphic accounting for 70.24% of the total number of fragments. Cluster analysis showed clear-cut separation of the Gossypium hirsutum and Gossypium arboreum genotypes while, narrow genetic base was observed among colored cottons. Four clusters were formed (I, II, III and IV). All the cotton genotypes except 'CIM-446' and 'NIAB-801' clustered together. Cluster IV contained Gossypium arboreum. The study demonstrated the efficient and reliable use of RAPDs for analyzing genetic variation in colored and white-linted genotypes of cotton.