生物有机肥对土壤微生物群落结构变化及西瓜枯萎病的调控

Regulation of soil microbial community structures and watermelon Fusarium wilt by using bio-organic fertilizer

摘要:

[目的] 研究施用生物有机肥处理土壤后对西瓜枯萎病发生的影响，明确可能与西瓜枯萎病发病密切相关的土壤微生物群落结构。[方法] 设置2组不同年份材料对比，依次为施用生物有机肥后2016年发病期（CK2016、T12016）和2017年发病期（CK2017、T12017）。基于16S rRNA序列测定，利用Illumina Miseq高通量测序平台对施用生物有机肥后不同年份的土壤微生物群落组成和差异进行测序分析。[结果] 试验结果发现，不同年份的土壤微生物群落中alpha多样性指数并无明显的差异，但是施用生物有机肥后的土壤相比对照土壤中细菌群落多样性略有增高。不同年份土壤细菌群落结构在门水平上差异不显著，其中变形菌门和硬壁菌门是构成这两个年份土壤细菌的重要组成部分，同时也是比较稳定的微生物类群。在属水平上分析发现主要动态变化菌属为芽孢杆菌属、肠球菌属、乳球菌属及水恒杆菌属。通过Spearman分析发现它们与西瓜枯萎病发生率的关系均为负相关。[结论] 施用生物有机肥可帮助西瓜连作土壤的生态修复，对枯萎病防治起到一定的作用。通过对施用生物有机肥的不同年份土壤微生物种群结构动态变化及对枯萎病发生率呈正负相关的微生物菌属的分析研究，为如何利用调节土壤微生物群落结构来防治西瓜枯萎病提供了新的思路。

关键词:西瓜;土壤微生物群落;生物有机肥;高通量测序;枯萎病

Abstract:

[Objective] The objective of our study was to compare the soil bacterial communities by using bio-organic fertilizer in disease occurring period, and to excavate the closely related bacterial genera to Watermelon Fusarium wilt.[Methods] The V3-V4 region of the 16S rRNA gene in bacterial DNA was amplified using the polymerase chain reaction technique and sequenced by the Illumina Miseq platform to diversity analysis of the soil microbial community composition after application of bio-organic fertilizer in different years (2016 onset stage and 2017 onset stage).[Results] There was no significant difference in alpha diversity indices among soil microbial community diversity at different years, but the diversity richness increased slightly after applying bio-organic fertilizer by comparison with the control. At phylum level, the Proteobacteria and Firmicutes were the relatively stable bacterial communities in these two periods. However, at genus level, the major dynamic bacteria were Bacillus, Enterococcus, Lactococcus and Mizugakiibacter. Furthermore, the Spearman analysis showed that they were negatively correlated with the watermelon Fusarium wilt disease morbidity.[Conclusion] The application of bio-organic fertilizer plays a certain role in the control of watermelon Fusarium wilt by helping ecological restoration of microbial communities in continuously cropped watermelon-growing soil. Thus, the approach to identify the dynamic changes of soil microbes and find out their relationships between the incidence of watermelon Fusarium wilt provided a new idea of helping control watermelon Fusarium wilt by adjusting soil microbial community structure.

Key words:watermelon;soil microbes;bio-organic fertilizer;Illumina Miseq;Fusarium wilt