Comparative Analysis of Genetic Diversity of Chinese and American Sugarcane(Saccharum spp.)Using SSR Markers

Sugarcane(Saccharum spp.)germplasm introduced from U.S.A.was an important type of parental materials and played a key role in Chinese sugaracane breeding program.In this study,genetic diversity of 48 accessions including 36 from China and 12 from U.S.A.was assessed by SSR markers.In 18 loci,a total of 257 alleles were detected with an average of 16.8.For most loci,there was no obvious difference in the allele numbers between the Chinese and American accessions.Difference was only found at several loci such as SSCIR36,SSCIR43,SSCIR32.Jaccard's similarity coefficient among the accessions was ranged from 0.3913 to 0.742 6 and that among the accessions from the same country was higher than that among the accessions between the two countries.Clustering based on Jaccard's coefficient using UPGMA showed the total 48 accessions could be clustered into three groups.Thirty-four Chinese accessions and four America accessions were clustered into a group.Eight American accessions were clustered into the second group and two accessions from crosses of "Yuenan niuzhe"(Saccharum officinarum L.)and Saccharum spontaneaum L.into the third group.The clustering analysis showed there were significant differences in the genetic base of the accessions from the two countries.It would be helpful to improve the genetic diversity of sugarcane varieties by using more American accessions in Chinese breeding program.It was also shown that there was considerable genetic difference between the offsprings from "Yuenan niuzhe" Saccharum officinarum L.)and other cultivars.It is recommended to use more germplasm of Saccharum officinarum L.in future breeding program.