Pandian Subramani, Satish Lakkakula, Rameshkumar Ramakrishnan, Muthuramalingam Pandiyan, Rency Arockiam Sagina, Rathinapriya Periyasamy, Ramesh Manikandan
Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, Tamil Nadu 630 003, India.
Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, Tamil Nadu 630 003, India.
Gene. 2018 May 5;653:80-90. doi: 10.1016/j.gene.2018.02.018. Epub 2018 Feb 8.
Finger millet (Eleusine coracana (L.) Geartn.) is one of the important small millets serves as a food security crop because of its high nutritional values. The complex tetraploid genome of finger millet requires a large number of informative, functional DNA markers for different applications in genetics and breeding. Yet, less number of simple sequence repeat (SSR) markers have been developed from expressed sequence tags in finger millet. In the present study, 56 new genic SSR markers were developed from publicly available drought related ESTs. The 43 polymorphic markers were used to evaluate polymorphism, revealed a range of PIC value 0.41 to 0.79. Our results suggest that, analyzed genotypes have high genetic diversity with an average gene diversity (h) of 0.176 and Shannon's information index (I) of 0.315. We conclude that there was a higher gene exchange within populations, by the value of overall gene flow (Nm) of 0.7721. The unweighted pair group method with arithmetic mean and neighbor joining dendrogram generated three main clusters to differentiate genotypes and these results were also confirmed by PCA and PCoA analysis. The high genetic diversity (77%) was found within the populations in the analysis of molecular variance. A Bayesian model-based cluster analysis evidenced a high extent of admixture between the gene pools from the different geographical origins. Population based cluster analyses pointed out a strong pattern of 'isolation by distance'. Overall, these results underscored that this study showed a significantly high level of polymorphism, adequate genetic diversity and population structure which expand the modern genetic resources and its utility in various applications in genetics and genomics including association mapping and breeding.
龙爪稷（Eleusine coracana (L.) Geartn.）是重要的小杂粮之一，因其高营养价值而成为粮食安全作物。龙爪稷复杂的四倍体基因组需要大量信息丰富的功能性DNA标记，以用于遗传学和育种的不同应用。然而，从龙爪稷的表达序列标签中开发的简单序列重复（SSR）标记数量较少。在本研究中，从公开可用的干旱相关EST中开发了56个新的基因SSR标记。43个多态性标记用于评估多态性，其PIC值范围为0.41至0.79。我们的结果表明，分析的基因型具有高遗传多样性，平均基因多样性（h）为0.176，香农信息指数（I）为0.315。我们得出结论，通过总体基因流（Nm）值0.7721可知，种群内存在较高的基因交换。采用算术平均的非加权配对组方法和邻接法树状图产生了三个主要聚类以区分基因型，主成分分析（PCA）和主坐标分析（PCoA）也证实了这些结果。分子方差分析发现种群内具有高遗传多样性（77%）。基于贝叶斯模型的聚类分析表明，来自不同地理起源的基因库之间存在高度混合。基于种群的聚类分析指出了强烈的“距离隔离”模式。总体而言，这些结果强调，本研究显示出显著高水平的多态性、足够的遗传多样性和种群结构，这扩展了现代遗传资源及其在遗传学和基因组学的各种应用中的效用，包括关联作图和育种。
