Abstract:

To reveal the genetic relationship among different mid-matured cotton germplasms, select parent materials for superior hybrid combinations, and finally obtain the target superior germplasms and approved varieties, the genetic diversity of 87 cotton varieties or lines was studied using SRAP markers. The polymorphic SRAP primers were selected from 80 pairs of primer combinations for PCR amplification among the test materials. The results showed that a total of 168 loci were detected using 17 pairs of polymorphic SRAP primers, 90 of which were polymorphic, with an average of 5.29 polymorphic loci per primer, and the polymorphic rate was 53.57%. Data analysis by NTSYS-pc2.11 software showed that the genetic similarity coefficient of 87 cotton materials ranged from 0.61 to 1.00, with an average of 0.82. When the genetic similarity coefficient was given as 0.73, 87 cotton materials could be clustered into two groups, of which the first group included 65 materials and the second group included 22 materials. The genetic diversity analysis suggests that the genetic basis of mid-matured cotton is relatively narrow, and the materials with distant genetic relationship should be selected as hybrid parents to create new mid-matured cotton germplasm resources in future.

Key words: mid-matured cotton, germplasm resources, SRAP, genetic relationship, genetic diversity