土壤熏蒸剂棉隆和生物菌肥对草莓连作土壤真菌多样性的影响

Effects of dazomet fumigation and biological fertilizer on strawberry soil fungal diversity under replant conditions

摘要:

【背景】草莓是我国和世界上重要的园艺作物，主要采用一年一栽的栽培模式，导致连作现象普遍存在，其中真菌性病害引起的土传病害是草莓栽培中面临的一个主要问题。【目的】以草莓连作土壤为材料，探讨土壤熏蒸剂棉隆加生物菌肥对草莓连作土壤微生物真菌多样性的影响，以期为草莓连作障碍治理提供理论依据。【方法】分别采集棉隆消毒前(A)、棉隆消毒后(B)、棉隆消毒后未添加生物菌肥(C1)和添加生物菌肥(C2)初花期的草莓连作土壤(或根际土壤)样本，提取DNA，通过PCR扩增建立文库，利用Hiseq 2500平台Illumina第二代高通量测序技术并结合相关生物信息学，分析土壤真菌ITS1区域的丰富度、多样性以及群落结构。【结果】从4个不同处理草莓连作土壤样本中获得了723个真菌OTU (Operational taxonomic unit)，其中子囊菌门和担子菌门均为优势真菌。多样性和丰富度研究发现，棉隆处理降低草莓连作土壤微生物丰富度和多样性；添加生物菌肥增加根际土壤生物丰富度，并降低其多样性。从门水平看，棉隆处理担子菌门真菌比例减少，子囊菌门真菌比例增加；添加生物菌肥处理两者比例均有增加。优势真菌群落分析表明棉隆消毒减少了枝顶孢属、曲霉属、管柄囊霉属、镰刀菌属、踝节菌属、链格孢属等真菌比例，增加了马拉色氏霉菌属、线孢虫草菌属、侧耳属等真菌比例；添加生物菌肥减少了管柄囊霉属、镰刀菌属、被孢菌属、轮枝菌属、隔指孢属等真菌比例，增加了曲霉属、青霉菌属、踝节菌属、简单壳菌属等真菌比例。【结论】采用棉隆消毒和生物菌肥处理草莓连作土壤可降低微生物真菌群落的多样性，并减少或灭杀土壤中的大部分致病菌属，增加有益菌属，起到有效防治草莓土传病害的作用。

Abstract:

[Background] Strawberry is an important horticultural crops in our country and in the world, but mainly cultivated with annual cropping system in the strawberry area so as to cause continuous cropping phenomenon. Soil-borne disease caused by fungal disease is a major problem in strawberry cultivation. [Objective] Strawberry rhizosphere soils were used as material to explore effects of dazomet fumigation and biological fertilizer on strawberry soil fungal diversity under replant conditions, so as to provide theoretical basis for control of strawberry continuous cropping obstacle. [Methods] Replant soils before (A) or after dazomet fumigation (B) were collected, genomic DNA was extracted, and PCR amplification was made to establish libraries, as the same treatments with the soil samples at stage of flowering with dazomet fumigation (C1) or dazomet fumigation and biological fertilizer (C2). In this study, the fungal ITS1 region was sequenced by Illumina high-throughput sequencing technology on Hiseq 2500 platform, and related biological analysis was conducted to explore the changes of soil fungal abundances, diversities and structures. [Results] A total of 723 fungal OTUs were obtained from 4 strawberry rhizosphere soil samples, among them, Ascomycota and Basidiomycota were the dominant fungi. The fungal abundances and diversities of replant soils were decreased with dazomet fumigation, while the fungal abundances were increased and the fungal diversities were decreased with dazomet fumigation and biological fertilizer. At phylum level, the proportion of Basidiomycota was decreased and Ascomycota was increased with dazomet fumigation, while both of them were increased with dazomet fumigation and biological fertilizer. The analysis of dominant fungal community shows that the fungal proportions were decreased in terms of Acremonium, Aspergillus, Funneliformis, Fusarium, Talaromyces, Alternaria and increased in terms of Malassezia, Ophiocordyceps, Pleurotus with dazomet fumigation, while which were decreased in terms of Funneliformis, Fusarium, Mortierella, Lecanicillium, Dactylella and increased in terms of Aspergillus, Penicillium, Talaromyces, Simplicillium. [Conclusion] In conclusion, fungal diversity was decreased, pathogenic fungals were limited and benificial fungals were boosted with dazomet fumigation and biological fertilizer in strawberry cropping soil. Our results indicated a combination of dazomet fumigation and biological fertilizer could more effectively reduce the strawberry disease.