Abstract:

In order to study the genetic variation of salinity related cotton germplasm, 47 upland cotton accessions including 23 salinity tolerant materials and 24 salinity sensitive materials were explored using 88 simple sequence repeat (SSR) markers. We detected a total of 338 alleles at 88 SSR loci with an average of 3.841 alleles per locus, 333 of these alleles were detected in salinity tolerant germplasm and 312 alleles in salinity sensitive germplasm. Mean polymorphism information content (PIC), the average effective numbers of alleles (Ne) and the average genotype diversity index (H′) were 0.613, 2.929 and 1.083 in salinity tolerant germplasm, and 0.605, 2.883 and 1.071 in salinity sensitive germplasm, respectively. The similarity coefficients were similar between salinity tolerant germplasm and salinity sensitive germplasm. They varied from 0.530 to 0.979 in salinity tolerant germplasm, with a wider range than in salinity tolerant germplasm (from 0.525 to 0.878). The varieties were clustered into one major group and two small groups. The high genetic similarity coefficients we observed in Chinese salinity tolerant germplasm indicated narrow pedigrees within the group. Our results are useful for assessing cotton pedigrees, improving cotton hybrids, and ultimately allowing for the improved utilization of salinity tolerant germplasm.

Key words: upland cotton, salinity tolerance, SSR, genetic similarity, breeding for salinity tolerance