Sustainable Field Crops Programme, Institute for Food and Agricultural Research and Technology (IRTA), Lleida, Spain.
PLoS One. 2019 Jul 15;14(7):e0219867. doi: 10.1371/journal.pone.0219867. eCollection 2019.
Assessment of genetic diversity and population structure in crops is essential for breeding and germplasm conservation. A collection of 354 bread wheat genotypes, including Mediterranean landraces and modern cultivars representative of the ones most widely grown in the Mediterranean Basin, were characterized with 11196 single nucleotide polymorphism (SNP) markers. Total genetic diversity (HT) and polymorphic information content (PIC) were 0.36 and 0.30 respectively for both landraces and modern cultivars. Linkage disequilibrium for the modern cultivars was higher than for the landraces (0.18 and 0.12, respectively). Analysis of the genetic structure showed a clear geographical pattern for the landraces, which were clustered into three subpopulations (SPs) representing the western, northern and eastern Mediterranean, whereas the modern cultivars were structured according to the breeding programmes that developed them: CIMMYT/ICARDA, France/Italy, and Balkan/eastern European countries. The modern cultivars showed higher genetic differentiation (GST) and lower gene flow (0.1673 and 2.49, respectively) than the landraces (0.1198 and 3.67, respectively), indicating a better distinction between subpopulations. The maximum gene flow was observed between landraces from the northern Mediterranean SPs and the modern cultivars released mainly by French and Italian breeding programmes.
对作物的遗传多样性和群体结构进行评估对于育种和种质资源保护至关重要。本研究利用 11196 个单核苷酸多态性（SNP）标记，对包括地中海地方品种和现代品种在内的 354 个面包小麦基因型进行了分析，这些现代品种代表了地中海盆地广泛种植的品种。地方品种和现代品种的总遗传多样性（HT）和多态信息含量（PIC）分别为 0.36 和 0.30。现代品种的连锁不平衡高于地方品种（分别为 0.18 和 0.12）。遗传结构分析显示，地方品种具有明显的地理模式，可分为代表地中海西部、北部和东部的三个亚群（SP），而现代品种则根据其育种计划进行了结构划分：CIMMYT/ICARDA、法国/意大利和巴尔干/东欧国家。现代品种的遗传分化（GST）高于地方品种（分别为 0.1673 和 0.1198），基因流（Nm）低于地方品种（分别为 2.49 和 3.67），表明亚群之间的区分更好。在北方地中海 SP 的地方品种和主要由法国和意大利的育种计划培育的现代品种之间观察到最大的基因流。
