Diversity Analysis in Core Accessions of Upland Cotton [Gossypium htrsutum L.)

摘要

Genetic diversity amongst 94 upland cotton accessions from the set of core collection was analyzed using RAPD, SRAP, TRAP and SSR markers. A total of 55 primers (22 SSR, 14 SRAP, 8 TRAP and 11 RAPD) were employedfor screening of 94 accessions, of which 48 primers (20 SSR, 13 SRAP, 5 TRAP and 10 RAPD) were polymorphic. These 55 primers amplified a total of277fragments of which 157 were polymorphic which corresponds to 56.7 percent polymorphism across 94 accessions. The polymorphism detected by SSR, SRAP, TRAP and RAPD was 88.4, 47.25, 56.75 and 26.98 percent respectively. The size of amplified fragments ranged from 300 bp to 3 kb, 170 bp to 3kb, 120 to 920 bp and 150 to 400 bp while the similarity coefficient (SC) values ranged from 0.83 to 1,0.71 to0.98, 0.56 to 0.94, and 0.31 to 0.94 for RAPD, SRAP, TRAP and SSR respectively. The combined marker analysis revealed an overall SC rangedfrom 0.70 to 0.94 with an average of 0.82.The dendrogram analysis using RAPD+SRAP+TRAP+SSR similarity matrix data indicated total of eight major clusters and three accessions as outgroup members (Cat-3773, Cat-1911, Cat-3056). The lowest SC ofO. 70 was found between Cat-299 with Cat-3773, Cat-3846 and Cat-3904 while the highest SC of 0.94 was found between Cat-692 and Cat-1034. The most distinct genotypes were identified from the different clusters and such a diverse group of genotypes can be used in breeding programme and also for linkage disequilibrium studies.