轮纹病是影响梨产业的重要病害之一，获得安全有效的病害防治措施是解决产业问题的迫切需求。病毒介导真菌弱致病力是病害生物防治的研究热点和有效途径。miRNA在抗病防御中具有重要调控作用，在尚未发现有效的主效抗病基因，通过调控梨轮纹病菌miRNA发挥病毒致病作用以及抑制抗病毒反应有利于探讨利用真菌病毒防治轮纹病害的可能性。课题已获得弱毒菌株LW-C以及与病毒互作的候选Bd-miR5636的基础上，从Bd-miRNA产生机制、表达模式和作用机制方面采用正反遗传转化及生物学方法对Bd-miR5636及靶基因激酶复合物（BdCDKc）和病毒基因在轮纹病菌中进行功能分析，考察转化子生物学变化及对病毒的影响，解析参与抑制真菌抗病毒反应的病毒基因功能，全面揭示梨轮纹病菌抗病毒作用机制。在理论上有助于理解宿主miRNA对抗病毒侵染或者有助病毒复制互作过程的认识，为病毒介导真菌弱致病力生物防治提供有益基因资源。

Pear ring rot disesese induced by Botryosphaeria dothidea pathogen is one of the important disease, which has seriously hindered the development of pear industry. It is urgent to obtain safe and effective measures of control disease to solve the industrial problems of pear. The application of mycovirus-mediated fungal hypovirulence has been a hot topic of research and an effective approach for biological control of fungal diseases. Increasing evidences showed that miRNAs play important regulatory roles in disease-resistant defensive response. Therefore, in the absence of effective resistance genes in pear, it is helpful to explore the possibility of mycovirus to prevent and control the disease by manipulation Bd-miRNA genes. Bd-miRNAs play the role of regulating the genes responsible for the mycoviral virulence and inhibiting antiviral response in B. dothidea. In this study, on the basis of obtaining the hypovirulent LW-C strain and the candidate Bd-miR5636 involved in the interaction between mycovirus and host, the regulation of Bd-miR5636 on expression of the predicted targets of BdCDKc (Cyclin-dependent protein kinase complex) and viral genes in B. dothidea will be analyzed. Using of overexpresion and knock-out methods, variations between transformants of Bd-miR5636 and its target genes, and wild-type strain will be investigated to analyze the Bd-miR5636 effect on the biological change in B. dothidea and BdCV1. Meanwhile we analyze BdCV1 gene function involved in inhibiting the antiviral response of fungi. The performance of the project will clarify the regulatory mechanism of Bd-miR5636 in the interaction between B. dothide and BdCV1. In theory, it is helpful to understand how small RNA play the role of antiviral response or facilitate mycoviral replication in fungi host, and provide valuable genetic resources for the mycovirus-mediated biological control of fungal diseases in practice.