Chen Honglin, Qiao Ling, Wang Lixia, Wang Suhua, Blair Matthew Wohlgemuth, Cheng Xuzhen
National Key Facility for Crop Gene Resources Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
National Key Facility for Crop Gene Resources Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China; College of Agriculture, Shanxi Agricultural University, Taigu 030801, China.
Gene. 2015 Jul 25;566(2):175-83. doi: 10.1016/j.gene.2015.04.043. Epub 2015 Apr 17.
Mung bean is an important legume crop in tropical and subtropical countries of Asia and has high nutritional and economic value. However the genetic diversity of mung bean is poorly characterized. In this study, our goal was to develop and use microsatellite simple sequence repeat (SSR) markers for germplasm evaluation. In total, 500 novel expression sequence tag EST-based SSRs (eSSRs) and genomic SSRs (gSSRs) were developed from mung bean transcriptome and genome sequences. Of these, only 58 were useful for diversity evaluation in a panel of 157 cultivated and wild mung bean accessions from different collection sites in East Asia. A total of 2.66 alleles were detected on average per locus which shows that polymorphism is generally low for the species. The average polymorphic information content (PIC) of gSSRs was higher than eSSRs and most of the polymorphic gSSRs were composed of di- and tri-nucleotide repeats (52.4% and 38.1% of all loci, respectively). The genotypes were differentiated into nine subgroups by cluster analysis, and the wild mung bean accessions separated well from the cultivated accessions. Analysis of molecular variance indicated that 22% of variance was observed among populations and 78% was due to differences within populations. Clustering, population structure analyses showed that non-Chinese cultivated and wild mung bean accessions were separated from Chinese accessions, but no geographical distinctions existed between genotypes collected in China. Interestingly, the average PIC value of cultivated mung bean (0.36) was higher than that of wild mung bean (0.25) showing that further collecting and wide crosses are necessary for mung bean improvement.
绿豆是亚洲热带和亚热带国家的一种重要豆类作物，具有很高的营养和经济价值。然而，绿豆的遗传多样性特征尚不明确。在本研究中，我们的目标是开发并使用微卫星简单序列重复（SSR）标记进行种质评估。总共从绿豆转录组和基因组序列中开发了500个基于新的表达序列标签（EST）的SSR（eSSR）和基因组SSR（gSSR）。其中，只有58个对来自东亚不同收集地点的157份栽培和野生绿豆种质的多样性评估有用。每个位点平均检测到2.66个等位基因，这表明该物种的多态性普遍较低。gSSR的平均多态信息含量（PIC）高于eSSR，并且大多数多态性gSSR由二核苷酸和三核苷酸重复组成（分别占所有位点的52.4%和38.1%）。通过聚类分析将基因型分为九个亚组，野生绿豆种质与栽培种质明显分开。分子方差分析表明，22%的方差存在于群体间，78%是由于群体内差异所致。聚类和群体结构分析表明，非中国的栽培和野生绿豆种质与中国种质分开，但在中国收集的基因型之间不存在地理差异。有趣的是，栽培绿豆的平均PIC值（0.36）高于野生绿豆（0.25），这表明为了改良绿豆，有必要进一步收集和进行广泛杂交。
