Genetic Diversity Analysis and Identification of Insect-Resistant Cottons Based upon SSR Markers

Genetic diversity analysis and identification of 14 different germplasm varieties(lines) from insect-resistant cotton by the simple sequence repeats(SSR) amplified polymorphic DNAs techniques were reported.A total 126 pairs of SSR primers were used to the 14 different germplasm varieties(lines) using SSR techniques and finally 22 pairs of primers could produce steady polymorphisms.A total of 97 DNA fragments were scored among all materials,averaging 4.5 for each pair of primer,of which,69(71.1%) bands were polymorphic.Cluster analysis by the unweighted pair group method of arithmetic means(UPGMA) showed that 14 varieties(lines) could be divided into two groups with genetic distance from 0.035 to 1.056.Cluster analysis revealed that 14 lines could be divided into two groups and the first group that included 11 varieties mainly were transgenic pest-resistant cotton,and the second group that included 3 varieties,were the nectariless pest-resistant cotton.This experiment demonstrated that SSR analysis could reliably determine genetic relationships within a diverse array of cotton varieties.The analysis revealed that it was corresponding to the geographical distribution and most of the lines had a narrow genetic base.