Fan L N, Deng H H, Luo Q W, He H Y, Li Y, Wang Q N, Huang Z X, Wu J T, Li Q W, Liu S M, Qi Y W
Guangdong Key Laboratory of Sugarcane Improvement and Biorefinery, Guangzhou Sugarcane Industry Research Institute, Guangzhou, China.
Genet Mol Res. 2013 Nov 26;12(4):5916-25. doi: 10.4238/2013.November.26.1.
Saccharum spontaneum is the most variable wild relative of sugarcane with potential for use in sugarcane improvement programs. In order to help preserve and exploit this species, 152 accessions from eight major geographical regions in China, including Hainan, Guangdong, Guangxi, Yunnan, Sichuan, Guizhou, Fujian, and Jiangxi provinces, were investigated by analyzing 20 simple sequence repeats (SSRs), including 11 genomic SSRs (gSSRs) and nine SSRs developed from expressed sequence tags (EST-SSRs). A total of 454 alleles were generated by the 20 SSRs, with 295 and 159 alleles detected by gSSRs and EST-SSRs respectively. The Mantel test showed significant correlation between genetic matrixes among the studied accessions revealed by gSSRs versus EST-SSRs, although the average polymorphism of EST-SSRs (17.7) was much lower than that of gSSRs (26.8). Among the eight provinces, collections from Guizhou were the most diverse and those from Guangdong were the most distinct. Clustering analysis and principal component analysis accordantly classified the accessions into four groups, which were "Southwest group", "Hainan group", "Guangdong group", and "Guangxi group", based on the geographical origin of the major accessions in each group, demonstrating that geographical factors play an important role in the pattern of genetic structure of Chinese S. spontaneum. As two (Guizhou and Yunnan) of the three provinces with highest genetic diversity are located in southwest China, we concluded that southwest China is the region with the highest genetic diversity of S. spontaneum.
甜根子草是甘蔗最具变异性的野生近缘种，在甘蔗改良计划中有潜在利用价值。为了有助于保护和利用该物种，通过分析20个简单序列重复（SSR）标记，包括11个基因组SSR（gSSR）和9个从表达序列标签（EST-SSR）开发的SSR，对来自中国八个主要地理区域（包括海南、广东、广西、云南、四川、贵州、福建和江西）的152份种质进行了研究。20个SSR共产生454个等位基因，其中gSSR和EST-SSR分别检测到295个和159个等位基因。Mantel检验表明，gSSR和EST-SSR揭示的研究种质间遗传矩阵存在显著相关性，尽管EST-SSR的平均多态性（17.7）远低于gSSR（26.8）。在这八个省份中，贵州的收集物多样性最高，广东的收集物最为独特。聚类分析和主成分分析一致地将种质分为四组，即“西南组”、“海南组”、“广东组”和“广西组”，基于每组主要种质的地理来源，表明地理因素在中国甜根子草遗传结构模式中起重要作用。由于遗传多样性最高的三个省份中的两个（贵州和云南）位于中国西南部，我们得出结论，中国西南部是甜根子草遗传多样性最高的地区。
