Mengistu Dejene Kassahun, Kidane Yosef Gebrehawaryat, Catellani Marcello, Frascaroli Elisabetta, Fadda Carlo, Pè Mario Enrico, Dell'Acqua Matteo
Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
Department of Dryland Crop and Horticultural Sciences, Mekelle University, Mekelle, Ethiopia.
Plant Biotechnol J. 2016 Sep;14(9):1800-12. doi: 10.1111/pbi.12538. Epub 2016 Feb 8.
Durum wheat (Triticum turgidum subsp. durum) is a key crop worldwide, and yet, its improvement and adaptation to emerging environmental threats is made difficult by the limited amount of allelic variation included in its elite pool. New allelic diversity may provide novel loci to international crop breeding through quantitative trait loci (QTL) mapping in unexplored material. Here, we report the extensive molecular and phenotypic characterization of hundreds of Ethiopian durum wheat landraces and several Ethiopian improved lines. We test 81 587 markers scoring 30 155 single nucleotide polymorphisms and use them to survey the diversity, structure, and genome-specific variation in the panel. We show the uniqueness of Ethiopian germplasm using a siding collection of Mediterranean durum wheat accessions. We phenotype the Ethiopian panel for ten agronomic traits in two highly diversified Ethiopian environments for two consecutive years and use this information to conduct a genome-wide association study. We identify several loci underpinning agronomic traits of interest, both confirming loci already reported and describing new promising genomic regions. These loci may be efficiently targeted with molecular markers already available to conduct marker-assisted selection in Ethiopian and international wheat. We show that Ethiopian durum wheat represents an important and mostly unexplored source of durum wheat diversity. The panel analysed in this study allows the accumulation of QTL mapping experiments, providing the initial step for a quantitative, methodical exploitation of untapped diversity in producing a better wheat.
硬粒小麦(Triticum turgidum subsp. durum)是全球一种关键作物,然而,其精英种质库中所含等位基因变异数量有限,这使得它的改良以及适应新出现的环境威胁变得困难。新的等位基因多样性可能通过对未开发材料进行数量性状基因座(QTL)定位,为国际作物育种提供新的基因座。在此,我们报告了数百份埃塞俄比亚硬粒小麦地方品种和几个埃塞俄比亚改良品系的广泛分子和表型特征。我们检测了81587个标记,对30155个单核苷酸多态性进行评分,并利用它们来调查该群体的多样性、结构和基因组特异性变异。我们使用地中海硬粒小麦种质的旁系收集品展示了埃塞俄比亚种质的独特性。我们连续两年在两个高度多样化的埃塞俄比亚环境中,对埃塞俄比亚群体的十个农艺性状进行表型分析,并利用这些信息进行全基因组关联研究。我们鉴定出了几个支撑感兴趣农艺性状的基因座,既证实了已报道的基因座,也描述了新的有前景的基因组区域。这些基因座可以通过现有的分子标记有效地进行靶向,以便在埃塞俄比亚和国际小麦中进行标记辅助选择。我们表明,埃塞俄比亚硬粒小麦是硬粒小麦多样性的一个重要且大多未被探索的来源。本研究中分析的群体允许积累QTL定位实验,为在培育更好的小麦过程中定量、系统地利用未开发的多样性提供了第一步。