Zhu Zhixian, Yu Cui, Dong Zhaoxia, Mo Rongli, Zhang Cheng, Liu Xinxin, Zuo Yuanyuan, Li Yong, Deng Wen, Hu Xingming
Institute of Economic Crops, Hubei Academy of Agricultural Sciences, Wuhan 430064, China.
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Plant Dis. 2024 Feb;108(2):502-512. doi: 10.1094/PDIS-02-23-0223-RE. Epub 2024 Feb 20.
Mulberry fruit sclerotiniose is a prevalent disease caused by the fungal species , , and of the order Helotiales, and severely affects the production of mulberry. However, these species have only been identified using morphological and rDNA-ITS sequence analyses, and their genetic variation is unclear. To address this, morphological and two-locus (ITS and ) phylogenetic analyses were conducted using culture-dependent and independent methods for 49 samples from 31 orchards across four provinces in China. Illumina MiSeq sequencing was used to assess the fungal communities obtained from fruits varying in disease severity and color from an orchard in Wuhan. Conidial suspensions of and isolated from diseased fruits, diseased fruits affected with hypertrophy and pellet sorosis sclerotiniose, and mycelia of were determined to be pathogenic to the mulberry cultivar YSD10. However, fruits inoculated with mycelia exhibited nontypical disease symptoms, and mycelia and conidia obtained from and strains were not pathogenic. Maximum parsimony and Bayesian analyses using the sequences of the assessed loci indicated species variability with no evidence of geographic specialization. Metagenomic analysis revealed that the diversity of fungal communities was reduced with disease progression. Furthermore, within a single fruit, the presence of two spp. was detected. These results provide novel insights into spp., revealing the secondary infections caused by conidia in diseased fruits, genetic variations of the pathogens, and the occurrence of coinfection. This improved understanding of fungal pathogens will aid in developing effective disease control strategies.
桑椹菌核病是由柔膜菌目真菌、和引起的一种常见病害，严重影响桑树生产。然而，这些菌种仅通过形态学和rDNA-ITS序列分析进行鉴定，其遗传变异尚不清楚。为了解决这一问题，采用依赖培养和不依赖培养的方法，对来自中国四个省份31个果园的49个样本进行了形态学和双基因座（ITS和）系统发育分析。利用Illumina MiSeq测序评估了从武汉一个果园中病害严重程度和颜色不同的果实中获得的真菌群落。从病果、患肥大性和菌核性桑椹菌核病的病果中分离得到的和的分生孢子悬浮液，以及的菌丝体被确定对桑树品种YSD10具有致病性。然而，接种菌丝体的果实表现出非典型病害症状，从和菌株获得的菌丝体和分生孢子无致病性。使用评估基因座的序列进行的最大简约法和贝叶斯分析表明存在物种变异性，没有地理特化的证据。宏基因组分析表明，随着病害进展，真菌群落的多样性降低。此外，在单个果实中检测到两种菌的存在。这些结果为菌提供了新的见解，揭示了病果中分生孢子引起的二次感染、病原体的遗传变异以及共感染的发生。对真菌病原体的这种更好理解将有助于制定有效的病害控制策略。
