Udupa S M, Robertson L D, Weigand F, Baum M, Kahl G
International Center for Agricultural Research in the Dry Areas, Aleppo, Syria.
Mol Gen Genet. 1999 Mar;261(2):354-63. doi: 10.1007/s004380050976.
A set of 12 randomly selected (TAA)n microsatellite loci of the cultivated chickpea (Cicer arietinum L.) were screened in a worldwide sample comprising 72 landraces, four improved cultivars and two wild species of the primary gene pool (C. reticulatum and C. echinosperum) to determine the level and pattern of polymorphism in these populations. A single fragment was amplified from all the accessions with each of 12 sequence-tagged microsatellite site markers, except for one locus where no fragment was obtained from either of the two wild species. There was a high degree of intraspecific polymorphism at these microsatellite loci, although isozymes, conventional RFLPs and RAPDs show very little or no polymorphism. Overall, the repeat number at a locus (excluding null alleles) ranged from 7 to 42. The average number of alleles per locus was 14.1 and the average genetic diversity was 0.86. Based on the estimates obtained, 11 out of the 12 frequency distributions of alleles at the loci tested can be considered to be non-normal. A significant positive correlation between the average number of repeats (size of the locus) and the amount of variation was observed, indicating that replication slippage may be the molecular mechanism involved in generation of variability at the loci. A comparison between the infinite allele and stepwise mutation models revealed that for 11 out of the 12 loci the number of alleles observed fell in between the values predicted by the two models. Phylogenetic analysis of microsatellite polymorphism in C. arietinum showed no relationship between accession and geographic origin, which is compatible with the recent expansion of this crop throughout the world.
在一个包含72个地方品种、4个改良品种以及两个初级基因库野生种（网脉鹰嘴豆和刺籽鹰嘴豆）的全球样本中，对栽培鹰嘴豆（鹰嘴豆属）的一组12个随机选择的（TAA）n微卫星位点进行了筛选，以确定这些群体中的多态性水平和模式。除了一个位点在两个野生种中均未获得片段外，12个序列标签微卫星位点标记中的每一个都从所有材料中扩增出了单一片段。尽管同工酶、传统RFLP和RAPD显示出很少或没有多态性，但这些微卫星位点存在高度的种内多态性。总体而言，一个位点的重复数（不包括无效等位基因）范围为7至42。每个位点的平均等位基因数为14.1，平均遗传多样性为0.86。根据获得的估计值，所测试位点的12个等位基因频率分布中有11个可被认为是非正态的。观察到平均重复数（位点大小）与变异量之间存在显著正相关，这表明复制滑动可能是这些位点产生变异的分子机制。无限等位基因模型和逐步突变模型之间的比较表明，12个位点中有11个观察到的等位基因数落在两个模型预测的值之间。鹰嘴豆微卫星多态性的系统发育分析表明，材料与地理起源之间没有关系，这与该作物最近在全球的扩张情况相符。
