Analysis of the Cluster and Principal Component of Cotton Germplasm by ISSR Markers

The genetic diversity among 48 lines of cotton germplasm was analyzed by ISSR(inter-simple sequence repeat) markers.From 36 pairs of primers,10 pairs of polymorphic primers were selected.A total of 112 bands were amplified from 10 pairs of primers by ISSR,of which 101 bands(about 90.18%) were polymorphic.Each primer amplified 4 to 21 polymorphic bands with the average of 10.10.The average value of allelic polymorphism information content(PIC) and the percentage of polymorphic bands(PPB) were 0.76 and 87.88%,respectively.The 48 lines of cotton germplasm were clustered into two groups at GS(genetic similarities) = 0.66 and the link map was set up by UPMGA method in NTSYSpc 2.1.Principal component analysis(PCA) for ISSR data showed that PCA supported UPGMA clustering result.The results indicated that lower genetic diversity and narrow genetic basis were presented in the 48 lines of cotton germplasm.