Mazzucotelli Elisabetta, Sciara Giuseppe, Mastrangelo Anna M, Desiderio Francesca, Xu Steven S, Faris Justin, Hayden Matthew J, Tricker Penny J, Ozkan Hakan, Echenique Viviana, Steffenson Brian J, Knox Ron, Niane Abdoul A, Udupa Sripada M, Longin Friedrich C H, Marone Daniela, Petruzzino Giuseppe, Corneti Simona, Ormanbekova Danara, Pozniak Curtis, Roncallo Pablo F, Mather Diane, Able Jason A, Amri Ahmed, Braun Hans, Ammar Karim, Baum Michael, Cattivelli Luigi, Maccaferri Marco, Tuberosa Roberto, Bassi Filippo M
Council for Agricultural Research and Economics-Research Centre for Genomics and Bioinformatics, Fiorenzuola d'Arda, Italy.
Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy.
Front Plant Sci. 2020 Dec 21;11:569905. doi: 10.3389/fpls.2020.569905. eCollection 2020.
Representative, broad and diverse collections are a primary resource to dissect genetic diversity and meet pre-breeding and breeding goals through the identification of beneficial alleles for target traits. From 2,500 tetraploid wheat accessions obtained through an international collaborative effort, a Global Durum wheat Panel (GDP) of 1,011 genotypes was assembled that captured 94-97% of the original diversity. The GDP consists of a wide representation of ssp. modern germplasm and landraces, along with a selection of emmer and primitive tetraploid wheats to maximize diversity. GDP accessions were genotyped using the wheat iSelect 90K SNP array. Among modern durum accessions, breeding programs from Italy, France and Central Asia provided the highest level of genetic diversity, with only a moderate decrease in genetic diversity observed across nearly 50 years of breeding (1970-2018). Further, the breeding programs from Europe had the largest sets of unique alleles. LD was lower in the landraces (0.4 Mbp) than in modern germplasm (1.8 Mbp) at = 0.5. analysis of modern germplasm defined a minimum of 13 distinct genetic clusters (), which could be traced to the breeding program of origin. Chromosome regions putatively subjected to strong selection pressure were identified from fixation index ( ) and diversity reduction index () metrics in pairwise comparisons among decades of release and breeding programs. Clusters of putative selection sweeps (PSW) were identified as co-localized with major loci controlling phenology ( and ), plant height () and quality (gliadins and glutenins), underlining the role of the corresponding genes as driving elements in modern breeding. Public seed availability and deep genetic characterization of the GDP make this collection a unique and ideal resource to identify and map useful genetic diversity at loci of interest to any breeding program.
具有代表性、广泛且多样的种质资源库是剖析遗传多样性以及通过鉴定目标性状的有益等位基因来实现预育种和育种目标的主要资源。通过国际合作获得了2500份四倍体小麦种质，在此基础上组建了一个由1011个基因型组成的全球硬粒小麦群体（GDP），该群体涵盖了原始多样性的94%-97%。GDP包括广泛的ssp.现代种质和地方品种，以及经过挑选的二粒小麦和原始四倍体小麦，以实现最大程度的多样性。使用小麦iSelect 90K SNP芯片对GDP种质进行基因分型。在现代硬粒小麦种质中，来自意大利、法国和中亚的育种项目具有最高水平的遗传多样性，在近50年（1970-2018年）的育种过程中，遗传多样性仅出现适度下降。此外，欧洲的育种项目拥有最大数量的独特等位基因。在阈值为0.5时，地方品种的连锁不平衡（LD）（0.4 Mbp）低于现代种质（1.8 Mbp）。对现代种质的分析确定了至少13个不同的遗传簇（），这些簇可以追溯到其起源的育种项目。通过在不同发布年代和育种项目的成对比较中，利用固定指数（）和多样性降低指数（）指标，确定了可能受到强烈选择压力的染色体区域。确定了推定选择清除（PSW）簇与控制物候（和）、株高（）和品质（醇溶蛋白和谷蛋白）的主要基因座共定位，突出了相应基因在现代育种中的驱动作用。GDP的公共种子可获得性和深入的遗传特征使其成为一个独特且理想的资源，可用于识别和定位任何育种项目感兴趣位点的有用遗传多样性。
