Backiyalakshmi C, Vetriventhan Mani, Deshpande Santosh, Babu C, Allan V, Naresh D, Gupta Rajeev, Azevedo Vania C R
Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University (TNAU), Coimbatore, India.
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India.
Front Plant Sci. 2021 Aug 20;12:692463. doi: 10.3389/fpls.2021.692463. eCollection 2021.
Finger millet [ (L.) Gaertn.] is an important climate-resilient nutrient-dense crop grown as a staple food grain in Asia and Africa. Utilizing the full potential of the crop mainly depends on an in-depth exploration of the vast diversity in its germplasm. In this study, the global finger millet germplasm diversity panel of 314 accessions was genotyped, using the DArTseq approach to assess genetic diversity and population structure. We obtained 33,884 high-quality single nucleotide polymorphism (SNP) markers on 306 accessions after filtering. Finger millet germplasm showed considerable genetic diversity, and the mean polymorphic information content, gene diversity, and Shannon Index were 0.110, 0.114, and 0.194, respectively. The average genetic distance of the entire set was 0.301 (range 0.040 - 0.450). The accessions of the race (0.326) showed the highest average genetic distance, and the least was in the race (0.275); and higher genetic divergence was observed between and (0.320), while the least was between and (0.281). An average, landrace accessions had higher gene diversity (0.144) and genetic distance (0.299) than the breeding lines (0.117 and 0.267, respectively). A similar average gene diversity was observed in the accessions of Asia (0.132) and Africa (0.129), but Asia had slightly higher genetic distance (0.286) than African accessions (0.276), and the distance between these two regions was 0.327. This was also confirmed by a model-based STRUCTURE analysis, genetic distance-based clustering, and principal coordinate analysis, which revealed two major populations representing Asia and Africa. Analysis of molecular variance suggests that the significant population differentiation was mainly due to within individuals between regions or between populations while races had a negligible impact on population structure. Finger millet diversity is structured based on a geographical region of origin, while the racial structure made negligible contribution to population structure. The information generated from this study can provide greater insights into the population structure and genetic diversity within and among regions and races, and an understanding of genomic-assisted finger millet improvement.
龙爪稷[ (L.) Gaertn.]是一种重要的适应气候变化且营养丰富的作物，在亚洲和非洲作为主粮种植。充分发挥该作物的潜力主要取决于对其种质资源中广泛多样性的深入探索。在本研究中，利用DArTseq方法对314份全球龙爪稷种质资源多样性样本进行基因分型，以评估遗传多样性和群体结构。经过筛选，我们在306份样本上获得了33,884个高质量单核苷酸多态性(SNP)标记。龙爪稷种质资源表现出相当大的遗传多样性，平均多态信息含量、基因多样性和香农指数分别为0.110、0.114和0.194。整个样本集的平均遗传距离为0.301(范围为0.040 - 0.450)。 族的样本平均遗传距离最高(0.326)， 族最低(0.275)； 族和 族之间的遗传差异较高(0.320)，而 族和 族之间最低(0.281)。总体而言，地方品种样本的基因多样性(0.144)和遗传距离(0.299)高于育种系(分别为0.117和0.267)。在亚洲样本(0.132)和非洲样本(0.129)中观察到类似的平均基因多样性，但亚洲样本的遗传距离(0.286)略高于非洲样本(0.276)，这两个地区之间的距离为0.327。基于模型的STRUCTURE分析、基于遗传距离的聚类和主坐标分析也证实了这一点，这些分析揭示了代表亚洲和非洲的两个主要群体。分子方差分析表明，显著的群体分化主要是由于区域内个体之间或群体之间的差异，而种族对群体结构的影响可以忽略不计。龙爪稷的多样性是基于起源的地理区域构建的，而种族结构对群体结构的贡献微不足道。本研究产生的信息可以为各区域和种族内部及之间的群体结构和遗传多样性提供更深入的见解，并有助于理解基因组辅助的龙爪稷改良。
