Zalapa Juan E, Brunet Johanne, Guries Raymond P
US Department of Agriculture, Agricultural Research Service, Vegetable Crops Research Unit, Department of Horticulture, 1575 Linden Drive, University of Wisconsin, Madison, WI 53706, USA.
Genome. 2008 Jul;51(7):492-500. doi: 10.1139/G08-034.
Elm breeding programs worldwide have relied heavily on Asian elm germplasm, particularly Ulmus pumila, for the breeding of Dutch elm disease tolerant cultivars. However, the extent and patterning of genetic variation in Asian elm species is unknown. Therefore, the objective of this research was to determine the extent of genetic diversity among 53 U. pumila accessions collected throughout the People's Republic of China. Using 23 microsatellite loci recently developed in the genus Ulmus, a total of 94 alleles were identified in 15 polymorphic and 4 monomorphic loci. The average number of alleles per locus was 4.9, with a range of 1-11 alleles. Gene diversity estimates per locus ranged from 0.08 to 0.87, and the non-exclusion probability for the 15 polymorphic loci combined was 0.7 x 10(-9). Nineteen region-specific alleles were identified, and regional gene diversity estimates were moderately high (0.48-0.57). The genetic relationships among accessions and regions were estimated by UPGMA and principal coordinate analysis. Both techniques discriminated all accessions and regions. Two microsatellite markers (UR175 + UR123 or Ulm-3) were sufficient to discriminate up to 99.7% of the accessions studied. This research provides useful information for DNA-based fingerprinting, breeding, ecological studies, and diversity assessment of elm germplasm.
全球的榆树育种计划在培育抗荷兰榆树病品种时，严重依赖亚洲榆树种质，尤其是白榆。然而，亚洲榆树物种的遗传变异程度和模式尚不清楚。因此，本研究的目的是确定在中国各地收集的53份白榆种质资源的遗传多样性程度。利用最近在榆属中开发的23个微卫星位点，在15个多态性位点和4个单态性位点共鉴定出94个等位基因。每个位点的平均等位基因数为4.9，范围为1 - 11个等位基因。每个位点的基因多样性估计值在0.08至0.87之间，15个多态性位点组合的非排除概率为0.7×10⁻⁹。鉴定出19个区域特异性等位基因，区域基因多样性估计值中等偏高（0.48 - 0.57）。通过UPGMA和主坐标分析估计种质资源和区域之间的遗传关系。两种技术都能区分所有的种质资源和区域。两个微卫星标记（UR175 + UR123或Ulm - 3）足以区分高达99.7%的研究种质资源。本研究为榆树种质资源的基于DNA的指纹识别、育种、生态研究和多样性评估提供了有用信息。
