Characterization of Genetic Diversity and Variation in Pathogenicity of the Rice False Smut Pathogen Ustilaginoidea virens from a Single Source
Characterization of Genetic Diversity and Variation in Pathogenicity of the Rice False Smut Pathogen Ustilaginoidea virens from a Single Source
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DOI：
10.1094/pdis-11-21-2546-re
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发表时间：
2022-09-08
期刊：
影响因子：
4.5
通讯作者：
Fang, Anfei
中科院分区：
文献类型：
--
作者：
Tan, Ze;Bai, Zhenxu;Fang, Anfei
稻曲病是由稻曲病菌（Ustilaginoidea virens）引起的水稻主要病害之一。本文对乌藨子的遗传多样性、进化和致病性进行了研究。virens可以为病害防治和品种选育提供更多的信息。与以往对不同地理居群的遗传多样性研究不同，本研究结果与文献报道的一致。本研究分析了绿僵菌的遗传变异。利用单核苷酸多态性分子标记技术对云南省某水稻品种不同穗部的病毒进行了分析。127个菌株的1,350 bp的DNA片段共鉴定出183个多态位点和5种单倍型hap_1 ~ hap_5，显示出一定的遗传多样性。Hap_1和Hap_3出现频率最高，是田间的优势单倍型。进一步分析表明，大多数水稻穗可以被不同的单倍型共感染，甚至少数小穗可以被多个单倍型共感染。聚类分析结果表明，所有菌株可分为5个遗传群。第I、II、III类聚在一起，区别于第IV、V类。根据F-ST值，在5个穗群体的两两比较中发现了显著的遗传变异，占总变异的72.45%。这种变异可能是由于田间微环境的不同和接种源分布的不均匀造成的。未加权对群法与算术平均聚类分析和群体结构表明，从YN 1，YN 2和YN 4收集的菌株的遗传组成，这是占主导地位的相同的遗传亚群，从YN 3收集的不同。11个分离物中发现了遗传重组，其中hap_2和hap_5可能是hap_1和hap_3有性杂交产生的遗传重组后代，根据种群结构和致病性分析，它们获得了比祖先更强的致病力。这些结果将有助于我们更好地了解乌藨子的遗传多样性、进化和侵染过程。virens，并帮助制定更有效的管理战略，包括新品种的抗性提高。
Rice false smut, caused by Ustilaginoidea virens, is one of the most destructive fungal diseases in rice-growing countries. Studies of the genetic diversity, evolution, and pathogenicity of U. virens can provide more information for disease control and cultivar breeding. Contrary to previous studies on the genetic diversity of different geographical populations of U. virens, this study analyzed the genetic variation of U. virens from different panicles of the same rice cultivar in a field in Yunnan Province using single nucleotide polymorphism molecular markers. A total of 183 polymorphic loci and five haplotypes, hap_1 to hap_5, were identified based on the 1,350-bp combined DNA fragment of 127 isolates, showing some genetic diversity. Hap_1 and hap_3 had the highest occurrence, indicating they were the dominant haplotypes in the field. Further analysis showed that most rice panicles could be coinfected by different haplotypes, and even a few spikelets could be coinfected by multiple haplotypes. The phylogeny indicated that all isolates were divided into five genetic groups. Groups I, II, and III clustered together and were distinguished from Groups IV and V. Significant genetic variations in five pairwise comparisons of panicle populations, accounting for 72.45% of the total variation, were found according to F-ST values. This variation might be caused by different field microenvironments and the uneven distribution of inoculum sources. An unweighted pair-group method with arithmetic means dendrogram and the population structure revealed that the genetic composition of the isolates collected from YN1, YN2, and YN4, which were dominated by the same genetic subgroup, was different from that collected from YN3. Finally, genetic recombination was found in 11 isolates; hap_2 and hap_5, probably as genetic recombination progenies produced by sexual hybridization between hap_1 and hap_3, acquired a greater virulence than their ancestors according to population structure and pathogenicity analyses. These results will help us understand the genetic diversity, evolution, and infection process of U. virens and aid in the development of more effective management strategies for rice false smut, including new cultivars with improved resistance.