【摘要】 采用8对微卫星分子标记对中国板栗(Castanea mollissima)的28个自然居群进行了遗传多样性与遗传结构分析。在849个个体上扩增得到128个等位基因,每位点平均等位基因数(A)为16。中国板栗居群的平均预期杂合度(HE)为0.678,平均观察杂合度(HO)为0.590。华中地区的中国板栗居群遗传多样性最高(A=8.112,HE=0.705,HO=0.618),其次为西北地区和华东地区,而西南地区遗传多样性最低(A=6.611,HE=0.640,HO=0.559)。基于无限等位基因模型(IAM)和基于逐步突变模型(SMM)的遗传分化系数分别为FST=0.120和RST=0.208。分子方差分析(AMOVA)结果表明中国板栗野生居群的遗传变异主要存在于居群内(87.16%)。Mantel检测揭示遗传距离与地理距离之间无显著相关性,表明基因流不是主导中国板栗居群遗传结构的关键因素。华中地区(尤其是神农架及其周边地区)是中国板栗遗传多样性的现代分布中心,因而应该得到优先保护,同时该区域的野生板栗居群可优先作为栽培板栗遗传育种的材料和基因库。更多还原

【Abstract】 Genetic diversity and population structure of 28 natural populations of Castanea mollissima were investigated by using microsatellite markers.A total of 128 alleles were identified in 849 individuals across the eight microsatellites analysed, with a mean value of 16 alleles per locus.The mean expected heterozygosity(HE) and observed heterozygosity(HO) across all populations were 0.678 and 0.590, respectively, and a higher level of diversity was found in populations from central China(A = 8.112, HE = 0.705, HO = 0.618) than those from other three regions(eastern, southwestern and northwestern China).Indices of genetic dif-ferentiation based on stepwise mutation model(SMM) and infinite allele model(IAM) were RST = 0.208 and FST = 0.120, respectively.No significant association between genetic distance and geographic distance was detected by Mantel test, suggesting gene flow is not a dominant factor shaping genetic structure of the species.The central China, particularly the area around the Shengnongjia Mountains, can be recognized as a modern center of genetic diversity of C.mollissima.Thus, natural populations of the species in this region deserve prior conservation and utilization for breeding programmes.更多还原