黄萎病不同发生程度棉田中土壤微生物多样性

作物根际土壤微生物群落对土壤生态及作物健康至关重要。以棉花黄萎病不同发生程度棉田的土壤为研究对象,采用理化分析、微生物纯培养及高通量测序技术对土壤理化性质及微生物数量、细菌丰度多样性进行综合分析。结果表明:在纯培养条件下,大丽轮枝菌无菌发酵滤液对细菌生长有明显的抑制作用;棉田接种大丽轮枝菌对土壤中细菌、真菌、放线菌的数量及细菌菌群丰度多样性未产生明显影响,不同采样时间的土壤中细菌菌群结构差异更大。土壤中大丽轮枝菌微菌核数量与棉花黄萎病的发生程度呈显著正相关。土壤肥力对土壤中微生物数量起主导作用,而水稻-棉花轮作能够使棉田有效降盐、减病、改善土壤肥力。通过生物防治、作物轮作、深翻等调控措施增加土壤中有益菌群数量、改善土壤生态、降低棉田土壤中大丽轮枝菌菌源数量是减轻棉花黄萎病危害的基础。

Analysis of soil microbial diversity in cotton fields differing in occurrence of cotton Verticillium wilt in Xinjiang

Soil microbial community composition of crop rhizosphere is very important in soil ecology and crop health. In this paper, the soil with different levels of cotton Verticillium wilt is the research object. Moreover, physical and chemical properties of soil, and rhizosphere microbial community diversity were analyzed with the technique of microbial pure culture, physical and chemical analysis and high-throughput sequencing. The results indicate that sterile fermentation liquor of Verticillium dahliae has obvious inhibitory effect on bacterial growth in pure culture conditions. After inoculation with V. dahliae, the quantity of bacteria, fungi, and actinomycetes in the cotton soil show little change compared to that in the control. High-throughput sequencing analysis indicates that bacterial genetic relationship in soil shows no significant change, and sampling time has a bigger impact on the bacterial population structure. Soil fertility plays a key role in determining the quantity of bacteria, fungi, and actinomycetes in continuous cotton cropping soil, in which Verticillium wilt occurrence is severe and significantly higher than that in the control field. Rice-cotton rotation cropping has a strong effect on reducing salt, plant diseases, and improving soil fertility. Microsclerotia content in soil has significant positive correlation with the incidence of cotton Verticillium wilt. Soil fertility, culture measures, and crop varieties mainly influence soil microorganism quantity; however, Verticillium wilt occurrence does not cause significant change in microbial quantity. Reducing the quantity of microsclerotia in soil is the fundamental method of controlling Verticillium wilt.