Salem Khaled F M, Sallam Ahmed
Plant Biotechnology Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), University of Sadat City, P. O. Box 79, Sadat City, Egypt.
Department of Genetics, Faculty of Agriculture, Assiut Univeristy, Assiut 71526, Egypt; Department of Agronomy & Horticulture, University of Nebraska-Lincoln, NE 68683-0915, USA.
C R Biol. 2016 Jan;339(1):1-9. doi: 10.1016/j.crvi.2015.11.003. Epub 2015 Dec 23.
Understanding the population structure and genetic diversity is a very important goal to improve the economic value of crops. In rice, a loss of genetic diversity in the last few centuries is observed. To address this challenge, a set of 22 lines from three different regions - India (two), and Philippines (six), and Egypt (14) - were used to assess the genetic diversity and the features of population structure. These genotypes were analyzed using 106 SSR alleles that showed a clear polymorphism among the lines. Genetic diversity was estimated based on the number of different alleles, polymorphism information content (PIC), and gene diversity. A total of 106 SSR alleles was identified from the 23 SSR loci and used to study the population structure and carry out a cluster analysis. All SSR loci showed a wide range of the number of different alleles extended from two (one loci) to seven alleles (three loci). Five and eight loci showed high PIC and gene diversity (≥0.70), respectively. The results of population structure are in agreement with cluster analysis results. Both analyses revealed two different subpopulations (G1 and G2) with different genetic properties in number of private alleles, number of different alleles (Na), number of effective alleles (Ne), expected heterozygosity (He), and Shannon's Information Index (SII). Our findings indicate that five SSR loci (RM 111, RM 307, RM 22, RM 19, and RM 271) could be used in breeding programs to enhance the marker-assisted selection through QTL mapping and association studies. A high genetic diversity found between genotypes which can be exploited to improve and produce rice cultivars for important traits (e.g. high agronomic features and tolerance to biotic or/and abiotic stresses).
了解种群结构和遗传多样性是提高作物经济价值的一个非常重要的目标。在水稻中，观察到过去几个世纪遗传多样性有所丧失。为应对这一挑战，使用了来自三个不同地区的22个品系——印度（2个）、菲律宾（6个）和埃及（14个）——来评估遗传多样性和种群结构特征。利用106个SSR等位基因对这些基因型进行分析，这些等位基因在品系间表现出明显的多态性。基于不同等位基因的数量、多态性信息含量（PIC）和基因多样性来估计遗传多样性。从23个SSR位点共鉴定出106个SSR等位基因，并用于研究种群结构和进行聚类分析。所有SSR位点显示出不同等位基因数量的广泛范围，从两个（一个位点）到七个等位基因（三个位点）。分别有五个和八个位点显示出高PIC和基因多样性（≥0.70）。种群结构的结果与聚类分析结果一致。两种分析都揭示了两个不同的亚群（G1和G2），它们在私有等位基因数量、不同等位基因数量（Na）、有效等位基因数量（Ne）、期望杂合度（He）和香农信息指数（SII）方面具有不同的遗传特性。我们的研究结果表明，五个SSR位点（RM 111、RM 307、RM 22、RM 19和RM 271）可用于育种计划，通过QTL定位和关联研究来加强标记辅助选择。在基因型之间发现了高遗传多样性，可利用其来改良和培育具有重要性状（如高农艺性状以及对生物或/和非生物胁迫的耐受性）的水稻品种。
