猕猴桃根腐病发生对其植株根际土壤真菌群落结构影响

Effects of Kiwifruit Root Rot Disease on Fungal Community Structures in Rhizosphere Soil of Kiwifruit Plants

【目的】分析猕猴桃根腐病感病植株和未感病植株根际土壤真菌群落变化,为研究猕猴桃根腐病发生机制及其调控技术提供依据。【方法】以浙江省台州市西部山区的天台县“红阳”猕猴桃种植基地为研究地点,选取连续种植4年的猕猴桃根腐病感病植株和未感病植株根际土壤真菌为研究对象,采用高通量测序技术,对比分析了猕猴桃感病植株和未感病植株根际土壤真菌群落结构与多样性指数的变化,以及测定分析了各处理根际土壤酶包括土壤脲酶、蔗糖酶和酸性磷酸酶活性。【结果】猕猴桃根腐病的发生极显著地降低了其根际土壤脲酶、蔗糖酶和磷酸酶的活性。感病植株根际土壤真菌群落丰富度指数显著低于未感病植株的根际土壤。在门分类水平上,猕猴桃感染根腐病后,其根际土壤真菌相对丰度降低的真菌门有担子菌门、未分类真菌门和接合菌门,其差异均达极显著水平(P<0.01)。其根际土壤真菌相对丰度升高的真菌门有子囊菌门,升高幅度达极显著水平(P<0.01)。在属分类水平上猕猴桃感病植株根际土壤真菌其相对丰度增加的菌群有赤霉属、丛赤壳属、镰刀菌属、假裸囊菌属和肉座菌属,其相对丰度的增加程度均达极显著水平(P<0.01)。其相对丰度降低的有未分类的伞菌纲、枝鼻菌属、粗糙孔菌属、线虫草属、支顶孢属、粪盘菌属和被孢霉属,其降低程度均达极显著水平(P<0.01)。【结论】猕猴桃感染根腐病后,感病植株根际土壤真菌在门和属水平上的菌群变化打破了植株根际土壤微生态系统中原先所存在着的微生物拮抗平衡关系,造成了猕猴桃抗性减弱而致此病发生和加重。

【Objective】The objective of this study is to research fungal community structures in rhizosphere soil of kiwifruit root rot disease infected and non-infected plants,in order to provide a theoretical basis for the mechanism of kiwifruit root rot disease and its regulation techniques.【Method】The rhizosphere soil samples were collected from"Hongyang"kiwifruit infected and non-infected with root rot disease for 4 consecutive years in western mountain areas of Huangyan,Taizhou city,Zhejiang province,which is one of the largest kiwifruit planting regional of Zhejiang province.The activities of soil enzymes including soil urease,sucrase and acid phosphatase in the rhizosphere of each treatment were determined and analyzed.Fungal community structures and diversity index of rhizosphere soil of kiwifruit were determined by high-throughput sequencing techniques.【Result】Compared with non-infected soil,the activities of urease,invertase,phosphatase in rhizosphere soil of kiwifruit infected by root rot disease were significantly decreased,and Chao1 indexes of fungal were decreased(P<0.05).At phylum level,the average relative abundance of some dominant fungal in rhizosphere soil of kiwifruit infected by root rot disease were lower than those of non-infected(P<0.01),such as Basidiomycota,fungi-unclassified and Zygomycota,while the average relative abundance of Ascomycota in rhizosphere soil of kiwifruit infected by root rot disease were higher than those of non-infected(P<0.01).At genus level,the average relative abundance of some dominant fungal in rhizosphere soil of kiwifruit infected by root rot disease were higher than those of non-infected with significant level(P<0.01),such as Gibberella,Nectria,Fu⁃sarium,Pseudogymnoascus and Hypocrea,while the average relative abundance of some fungal in rhizosphere soil of kiwifruit infected by root rot disease were lower than those of non-infected(P<0.01),including Agaricomycetes-unclassified,Cladorrhinum,Trechispora,Ophiocordyceps,Acremonium,Asco⁃bolus and Mortierella.【Conclusion】It is conclude that in rhizosphere soils of kiwifruit infected with root rot disease,the activities of important soil enzymes are lower.At the phylum and genus levels,great variations in the abundance of the dominant fungal have been confired.The changes in fungal communities in the rhizosphere soil disrupted the previously existing microbial antagonistic balance,resulting in weakened resistance of kiwifruit and occurrence of the disease.The finding could provide some theoretical reference for controlling kiwifruit root rot disease in Zhejiang Province.