Genetic and pathogenic variation of <i>Botrytis cinerea</i>, the causal agent of grey mould on <i>Panax ginseng</i> in China

Grey mould, caused by <i>Botrytis cinerea</i>, is an increasingly destructive disease of ginseng (<i>Panax ginseng</i>) in China. However, the extent of variation in the morphological characteristics of fungal colonies, genetic background and pathogenicity of different strains of this pathogen remains unknown. In this study, we isolated and identified 102 isolates of <i>B. cinerea</i> from ginseng. Among these, the sclerotial phenotype was dominant, followed by the mycelial and conidial phenotypes, with the proportion of each phenotype in the pathogen population showing no obvious variance across three provinces. Isolates were separated into three groups with differing pathogenicity, based on the diameter of the lesions they caused in pathogenicity tests; moderate-pathogenicity isolates were dominant, followed by strong- and weak-pathogenicity isolates. Variation was observed in the pathogenicity of isolates from three provinces. The Nei’s genetic diversity index and the Shannon’s information index of isolates from Jilin province was highest, followed by those from Liaoning, while isolates from Heilongjiang displayed the lowest genetic diversity. Furthermore, most of the genetic variance was found within the geographically defined <i>B. cinerea</i> populations; the low-genetic variance among populations was probably counteracted by gene flow. Results from this study provide a base understanding of genetic and pathogenic variation in <i>B. cinerea</i> populations from the main ginseng-growing regions of China, which will be helpful for further research and control of grey mould of ginseng.

由灰葡萄孢（Botrytis cinerea）引发的灰霉病，是我国人参（Panax ginseng）种植区日益严峻的毁灭性病害。然而，该病原菌不同菌株的菌落形态特征、遗传背景及致病力的变异程度仍有待阐明。本研究从人参样本中分离并鉴定出102株灰葡萄孢菌株。其中，菌核表型菌株为优势类群，其次为菌丝表型与分生孢子表型菌株；三类表型菌株在三个参试省份的病原菌种群中占比均无显著差异。根据致病力试验中各菌株诱导产生的病斑直径，将供试菌株划分为三类致病力等级：中等致病力菌株占比最高，强致病力菌株次之，弱致病力菌株占比最低。不同省份来源的菌株致病力均存在显著变异。吉林省来源菌株的奈氏遗传多样性指数（Nei’s genetic diversity index）与香农信息指数（Shannon’s information index）均为最高，辽宁省来源菌株次之，黑龙江省来源菌株的遗传多样性最低。进一步分析显示，绝大多数遗传变异存在于地理种群内部；种群间极低的遗传分化程度，可能由基因流（gene flow）所抵消。本研究结果阐明了我国人参主产区灰葡萄孢种群的遗传与致病力变异特征，可为后续人参灰霉病的防控及相关研究提供理论依据。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于中国地区引起人参灰霉病的病原菌Botrytis cinerea的遗传和致病性变异研究。研究从人参中分离了102个菌株，分析了其形态特征、致病性分组（以中等致病性为主）和遗传多样性（吉林省最高，黑龙江省最低），揭示了种群内部变异主导的特点，为疾病防控提供了科学依据。