United States Department of Agriculture-Agricultural Research Service-Southeastern Fruit and Tree Nut Research Laboratory, Byron, GA 31008.
Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK 73401.
Phytopathology. 2021 Feb;111(2):408-424. doi: 10.1094/PHYTO-12-19-0485-R. Epub 2021 Feb 8.
Scab (caused by ) is a major disease affecting peach in the eastern United States. The aims of the study were to characterize the mating-type loci in , determine whether they are in equilibrium, and assess the population genetic diversity and structure of the pathogen. The mating-type gene was identified in isolate JP3-5 in an available genome sequence, and the gene was PCR amplified from isolate PS1-1, thus indicating a heterothallic structure. Mating-type loci structures were consistent with those of other spp. ( and ): the mating-type gene is positioned between encoding a DNA lyase and a gene encoding a Pleckstrin homology domain. Primers designed to each of the mating-type genes and a reference gene were used as a multiplex PCR to screen a population ( = 81) of from various locations in the eastern United States. Mating types in five of the nine populations studied were in equilibrium. Among the 81 isolates, there were 69 multilocus genotypes. A population genetic analysis of the populations with >10 individuals (four populations) showed them to be genetically diverse. Linkage disequilibrium was found in five of nine populations with ≥4 isolates. A discriminant analysis of principal components indicated three genetic clusters, although extensive admixture was observed. Mating-type identification in provides a basis for understanding reproductive methods of the pathogen and can be a basis for further studies of the genetics of the peach scab pathogen.
结痂病（由 引起）是美国东部桃的主要病害。本研究的目的是鉴定 中的交配型基因座，确定它们是否处于平衡状态，并评估病原菌的群体遗传多样性和结构。在可用的基因组序列中，从 JP3-5 分离株中鉴定出交配型基因 ，并从 PS1-1 分离株中扩增出 基因，表明存在异宗配合结构。交配型基因座结构与其他 spp.（ 和 ）一致：交配型基因位于编码 DNA 核酸酶和 Pleckstrin 同源结构域的基因之间。设计了针对每个交配型基因和一个参考基因 的引物，并将其作为多重 PCR 用于筛选来自美国东部不同地点的 分离株群体（=81）。在所研究的九个种群中的五个种群中，交配型是平衡的。在 81 个分离株中，有 69 个多位点基因型。对具有 >10 个个体的四个种群的群体遗传分析表明，它们具有丰富的遗传多样性。在具有≥4 个分离株的九个种群中的五个中发现了连锁不平衡。主成分判别分析表明存在三个遗传聚类，但观察到广泛的混合。在 中进行交配型鉴定为了解病原菌的繁殖方法提供了基础，也可以为进一步研究桃疮痂病病原菌的遗传学提供基础。
