Working group session:
Germplasm and Genetic Stocks
Presentation type:
poster
Authors:
ZHAO, YUNLEI; GUO, ZHIJUN; CHEN, WEI; WANG, HONGMEI
Presenter:
Correspondent:
WANG, HONGMEI
Abstract:
Assessing genetic diversity of Gossypium hirsutum L. cultivars used in breeding contributed to studying genetic relationships among diverse cultivars, and detecting SSR markers associated with agronomic traits contributed to molecular assisted selection in breeding, both of which can improve the efficiency of traditional breeding. In this study, 172 upland cotton cultivars used in recent years of breeding practice were genotyped using 74 microsatellite markers. Genetic cluster and population structure were estimated using NTSYSpc-2.20 and Structure2.3.4 software, respectively. Association analysis between SSR markers and 3 agronomic traits were performed using TASSEL 2.1（general linear model, GLM）program. The results showed that 74 SSR markers revealed 246 alleles belonging to 148 loci, ranging from 2 to 7 with the average of 3.32 alleles per SSR marker. The polymorphic information content（PIC）for per marker is 0.0281—0.3733,with the average of 0.2730. The genetic similarity ranged from 0.2816—1,with the mean of 0.5369. The cluster analysis showed that all the accessions could be divided into twelve subgroups, which was in agreement with pedigree but not with origin. No significant correlation between geographic distance and genetic distance was observed. Low levels of genetic diversity for upland cotton in China were observed, with an average genetic similarity of 0.5369. However, some materials from America and Xinjiang region of China showed abundant genetic variation, which implying the necessarity of strengthening the exchange of gemplasms between different regions and expanding the genetic basis of upland cotton of China by introducing new resources from foreign countries. Structure analysis divided the whole cotton panel into three subpopulation. Association analysis detected 30 SSR loci associated with boll weight, lint, and Verticilium wilt resistance, respectively. These results have provided valuable information for the association mapping of important agronomic traits, as well as for the breeding and exploit of new cotton germplasms.
Key words: upland cotton; associate analysis; SSR; genetic diversity; population structure