Investigation into the Microbial Mechanisms of RSD Combined with Cellulose-Degrading Bacteria BE-91 in Suppressing Sclerotinia Disease in Chrysanthemums

菊花菌核病是由核盘菌(Sclerotinia sclerotiorum)引起的一种危害严重的真菌性病害。强还原土壤灭菌法(RSD)作为一种环境友好、普适性强的植物病害防治措施，已广泛用于病害防控的土壤前处理中。RSD处理中多采用农产品副产物，以纤维素为主要成分难以被快速降解，纤维素降解菌能够有效提高降解效率。本研究以菊花为研究对象，探究不同有机物料如麦麸、秸秆单独或复配并接种纤维素降解菌BE-91对菊花菌核病的防控效果。研究强还原土壤灭菌处理对菊花生物量、土壤理化性质和土壤酶活的影响，采用Illumina Miseq测序技术解析土壤真菌群落组成、丰度及其土壤环境因子间的相关性。结果显示：麦麸可优先作为RSD处理的物料选择；土壤理化因子中与土壤真菌群落结构相关性最高的是有机碳含量；土壤酶活中与土壤真菌群落结构相关性最高的是蔗糖酶活性；RSD可以改变土壤真菌群落的结构组成，促进有益微生物的繁殖，抑制核盘菌属(Sclerotinia)的累积，降低菊花菌核病的发生。Chrysanthemum sclerotinia, caused by Sclerotinia sclerotiorum, is a serious fungal disease. The strong reducing soil sterilization (RSD) method, as an environmentally friendly and widely applicable plant disease control measure, has been widely used in soil pretreatment for disease prevention and control. In RSD treatment, agricultural by-products, which are mainly composed of cellulose, are often used, and they are difficult to degrade rapidly. Cellulose-degrading bacteria can effectively improve the degradation efficiency. This study took chrysanthemum as the research object to explore the control effects of different organic materials such as wheat bran and straw, either alone or in combination, and inoculated with cellulose-degrading bacteria strain BE-91 on chrysanthemum sclerotinia rot. The effects of RSD treatment on chrysanthemum biomass, soil physical and chemical properties, and soil enzyme activities were studied. The Illumina Miseq sequencing technology was used to analyze the composition, abundance of soil fungal communities, and their correlations with soil environmental factors. The results showed that wheat bran could be preferred as the material for RSD treatment; the soil organic carbon content was the soil physical and chemical factor most correlated with the soil fungal community structure; soil sucrase activity was the soil enzyme activity most correlated with the soil fungal community structure; RSD could change the structure of soil fungal communities, promote the reproduction of beneficial microorganisms, inhibit the accumulation of Sclerotinia, and reduce the occurrence of chrysanthemum sclerotinia rot.