利用32个高粱(Sorghum bicolor L.)核基因组多态性SSR(simple sequence repeats)位点,以69份国外品种为对照,对12个地区的184份中国高粱地方品种进行了遗传多样性分析.研究结果表明,中国高粱的遗传多样性明显低于国外高粱.中国高粱和国外高粱的等位基因丰度(Rs)和基因多样性(He)分别为9.81、0.629和11.52、0.745.中国高粱的遗传多样性明显低于东非(He=0.732)、北美(He=0.707)和南亚(He=0.712)高粱,与南非高粱相当(He=0.609).不同地区中国高粱地方品种遗传变异水平存在明显差异,12个地区高粱种质等位基因丰度在3.64~4.88之间,基因多样性值在0.517~0.714之间.吉林高粱地方品种遗传变异最为丰富(He=0.714),与北美、南亚高粱相当.中国高粱与国外高粱之间遗传分化明显,而中国高粱地方品种地区间和类型间分化极弱.主成分分析(PCA)能够明显区分中外高粱种质但不能将中国高粱按地区或类犁分开.分子方差分析(AMOVA)表明,中外高粱间的遗传变异占全部参试材料遗传变异的20.43%.中国高粱遗传变异主要存在于地区内材料间(占总变异91.94%)或生态区内材料间(占总变异94.97%).在品种类型方面,中国高粱绝大部分遗传变异存在于穗型内材料间(占总变异97.93%).本研究支持中国高粱外来说的观点.
The genetic variation of 184 Chinese sorghum landraces (Sorghum bicolor L.) from a broad geographic area and representing different phenotypes, and 69 representative foreign cultivated sorghum accessions (world sorghum), was assessed using 32 nuclear SSR primer pairs. Overall, lower level of genetic diversity was detected in Chinese sorghum than in world sorghum. The allelic richness (Rs) and Nei's allele diversity (He) for Chinese sorghum and world sorghum were 9.81 and 0.629, and 11.52 and 0.745, respectively. Fewer unique alleles were detected in Chinese sorghum than in world sorghum. Chinese sorghum had a genetic diversity level lower than accessions from East Africa (He=0.732), North America (He=0.707) and South Asia (He=0.712);and was only comparable to those from South African accessions (He=0.609). Marked differences in level of genetic variation were revealed between Chinese sorghum landraces from 12 provinces, with Rs ranging from 3.64 to 4.88 and He from 0.517 to 0.714. Accessions from Jihn Province exhibited the highest level of genetic diversity among all regions in China, which was comparable to the sorghum in East Africa. The results indicated a strong divergence of Chinese sorghum from world sorghum, but a weak differentiation among Chinese sorghum both on regional and type bases. Principal component analysis (PCA) clearly separated Chinese sorghum from world accessions but could not separate Chinese sorghum into discrete geographical or phenotypic groups. Analysis of molecular variance (AMOVA) indicated that 20.43% of the total genetic variation was attributable to the difference between world and Chinese sorghum and 79.57% occurred among Chinese and world sorghum accessions. For Chinesesorghum, partitioning the total variation revealed that genetic diversity mainly existed among accessions within regions (91.94%)or eco-regions (94.97%) rather than among regions (8.06%) or eco-regions (5.03%). Similarly, a large portion (97.93%) of the total variation was found within types compared to among types (2.07%). Our study supports the view that Chinese sorghum is of African origin. Chinese sorghum may have experienced a long history of natural and human selection when largely isolated from outside world since prehistoric time. Suggestions for sorghum breeding programs were presented in the light of these data.