College of Plant Protection, Southwest University, Chongqing 400715, China.
Sericulture Station of Chongqing, Chongqing 400020, China.
Plant Dis. 2022 Jan;106(1):93-100. doi: 10.1094/PDIS-04-21-0750-RE. Epub 2022 Jan 21.
Rice false smut caused by is one of the most devastating fungal diseases of rice panicles worldwide. In this study, two novel molecular markers derived from single nucleotide polymorphism-rich genomic DNA fragments and a previously reported molecular marker were used for analyzing the genetic diversity and population structure of 167 . isolates collected from nine areas in the Sichuan-Chongqing region, China. A total of 62 haplotypes were identified, and a few haplotypes with high frequency were found and distributed in two to three areas, suggesting gene flow among different geographical populations. All isolates were divided into six genetic groups. Groups I and VI were the largest, with 61 and 48 isolates, respectively. The pairwise values showed significant genetic differentiation among all compared geographical populations. Analysis of molecular variance showed that intergroup genetic variation accounted for 40.17% of the total genetic variation, while 59.83% of genetic variation came from intragroup genetic variation. The unweighted pair-group method with arithmetic means dendrogram and population structure revealed that the genetic composition of isolates collected from Santai, Nanchong, Yongchuan, and Wansheng dominated by the same genetic subgroup was different from those collected from other areas. In addition, genetic recombination was found in a few isolates. These findings will help to improve the strategies for rice false smut management and resistance breeding, such as evaluating breeding lines with different isolates or haplotypes at different elevations and landforms.
由稻绿核菌引起的水稻假黑粉病是世界范围内稻穗最具破坏性的真菌病害之一。在本研究中，使用两种源自富含单核苷酸多态性的基因组 DNA 片段的新分子标记和先前报道的分子标记，对来自中国川渝地区 9 个地区的 167 个 分离株进行了遗传多样性和种群结构分析。共鉴定出 62 个单倍型，发现并分布在两个到三个地区的少数高频单倍型表明不同地理种群之间存在基因流。所有分离株被分为六个遗传群。群 I 和群 VI 是最大的，分别有 61 和 48 个分离株。成对的 值表明所有比较地理种群之间存在显著的遗传分化。分子方差分析表明，组间遗传变异占总遗传变异的 40.17%，而组内遗传变异占 59.83%。非加权组间平均法聚类和种群结构分析表明，来自三台、南充、永川和万胜的分离株的遗传组成与来自其他地区的分离株不同，主要由同一遗传亚群组成。此外，在少数分离株中发现了遗传重组。这些发现将有助于改善水稻假黑粉病管理和抗性育种策略，例如在不同海拔和地形下评估具有不同分离株或单倍型的育种品系。
