State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Yangling 712100, China.
Phytopathology. 2022 Feb;112(2):278-289. doi: 10.1094/PHYTO-07-20-0312-R. Epub 2022 Feb 1.
Wheat stripe rust, caused by f. sp. , is one of the most important diseases of wheat worldwide. In China, Longnan (LN) and Longdong (LD) in the south and east of Gansu province, respectively, are important f. sp. oversummering areas and are a source of f. sp. inoculum for the major wheat-growing regions in eastern China. Central Shaanxi (CS) is a wheat-growing region that acts as an important bridge zone for stripe rust epidemic development between LN and LD in the west and the Huanghuai wheat-growing region in the east, and thus, it plays an essential role in f. sp. epidemics in China. To study the relationships among f. sp. populations in the three regions (LN, LD, and CS), we sampled 284 isolates from different geographic locations. Based on 10 simple sequence repeat markers, the results demonstrated high genetic diversity in all three regions, although diversity did vary among regions, with LN > LD > CS. Genetic differentiation was lower, with more extensive gene flow between LD and CS. f. sp. populations in the CS region were genetically closer to those from LD than those from LN, which may be a result of geographical proximity and topography. A positive and significant correlation existed between linearized fixation index () and the log of geographical distances among all subpopulations. Linkage disequilibrium analysis showed that subpopulations of f. sp. from Qinzhou, Qincheng, Beidao, and Maiji from LN and Qianyang and Longxian from CS were in equilibrium ( > 0.05), suggesting that somatic hybridization and/or sexual reproduction may exist in these subpopulations.
小麦条锈病由 f. sp. 引起，是全球范围内最重要的小麦病害之一。在中国，甘肃省南部的陇南（LN）和东部的陇东（LD）是重要的 f. sp. 越夏区，是中国东部主要小麦种植区 f. sp. 接种体的来源。陕中（CS）是一个小麦种植区，它作为 LN 和 LD 西部与黄淮小麦种植区东部之间条锈病流行发展的重要桥梁地带，在中国 f. sp. 流行中起着重要作用。为了研究三个地区（LN、LD 和 CS）的 f. sp. 种群之间的关系，我们从不同地理位置采集了 284 个分离物。基于 10 个简单序列重复标记，结果表明所有三个地区都具有高度遗传多样性，尽管地区间存在多样性差异，LN > LD > CS。遗传分化较低，LD 和 CS 之间的基因流更为广泛。CS 地区的 f. sp. 种群在遗传上与 LD 地区的种群更为接近，而与 LN 地区的种群则较为疏远，这可能是由于地理位置和地形的接近。线性固定指数（）与所有亚种群之间地理距离的对数之间存在正显著相关性。连锁不平衡分析表明，来自 LN 的秦州、秦城、北道和麦积以及 CS 的千阳和陇县的 f. sp. 亚种群处于平衡状态（> 0.05），这表明这些亚种群中可能存在体细胞杂交和/或有性生殖。
