植烟土壤土传病害区微生物群落结构变化及修复

It is of great scientific importance for microbial ecology remediation of tobacco soil infected with soil-borne disease to investigate the temporal and spatial variations of soil microbial community structure，which would likely promote the enhancing of tobacco yield and quality. To illuminate the spatial and temporal variations of soil microbial community structure of tobacco planting areas in Guizhou province, three experimental sites are going to be set in the middle, east and west tobacco planting areas of this province, and this study will be carried out as follows: 1) the difference of rhizosphere microbial community structure of infected soil among the three regions are to be studied with Trflp and illumina-MiSeq methods to clarify the spatial variation of microbial community structure when the soil infecting soil-borne disease, 2) the discrepancy of rhizosphere microbial community structure between area with soil-borne disease and area without disease will be discussed with the same methods to disclosure the dynamic tendency of rhizosphere microbial community structure after the soil infected with disease, and 3) tobacco pot experiment and in situ field test with bioorganic fertilizer are going to be conducted to investigate the effects of bioorganic fertilizer on controlling the soil-borne disease and microbial ecologic remediation of infected soil, which will be conducive to the exploring of feasible soil remediation. All these results will provide a new insight to make the soil-borne disease infection in tobacco planting area clear and promote doable preventive for the disease, and furthermore, contribute to control the tobacco soil-borne disease and restore the microbial ecologic of infected soil in Guizhou province.

探明植烟土壤土传病害区微生物群落结构的时空变化对该土壤微生态修复具有重要的科学意义，并有望促进烟叶产量品质的提高。针对贵州烟区土传病害青枯病区土壤微生物群落结构时空变化尚不明确的问题，本项目在黔中丘原盆地、黔东低山丘陵以及黔西高原山地三大烟区设置试验点，采用Trflp、illumina-MiSeq测序等技术，1)分析烟区间发病区土壤微生物群落结构差异，以阐明土传病害发生时土壤微生物群落结构的空间变化；2)分析发病区和无病区的土壤微生物群落结构差异，以从土壤微生态学上揭示病发后微生物群落结构的变化动向；3)并进一步通过生物有机肥盆栽试验和田间原位试验明确生物有机肥对植烟土壤土传病害防治和微生态修复的效果，探索可行的土壤修复方式。研究结果将从土壤微生态方面分析烟区土传病害发生的时空差异、提出病害防治的可行措施，为贵州地区烟草土传病害的防治和植烟土壤的微生态修复提供科学依据。

明确植烟土壤土传病害区土壤因子及微生物群落结构的空间差异及病害发生前后的变化动向，对减缓土传病害下微生物群落结构的变化甚至修复土壤微生态环境并形成抑病型土壤具有重要的科学意义。项目针对上述问题，以贵州三大气候区下植烟土壤的青枯病害区域为研究对象开展调查研究，并探讨了生防菌对植烟土壤上青枯病害的防治效果和微生物群落结构的影响。研究结果表明，（1）植烟土壤青枯病害区患病烟株根际土壤和健康烟株根际土壤的养分和酶活性间均有着显著性差异。土壤养分状况、酶活性越高，更可能导致土传病害的发生。利用由pH、CEC、全氮、碱解氮及速效钾作为判别因子所构建的判别模型可对未知植烟土壤上的烟株是否易患青枯病进行预测预报。（2）不同气候区植烟土壤土传病害区土壤微生物群落结构大致相同，但其结构特征存在明显地空间变异。随着海拔升高，优势菌属鞘氨醇单胞菌属（Sphingomonas）相对丰度增加，芽单胞菌属（Gemmatimonas）丰度趋于稳定，且土传病害区优势属中相对丰度大于1%的属逐渐减少。（3）土传病害的发生会明显改变植烟土壤微生物群落结构。就土壤生态位来看，尽管患病烟株根际土壤和健康烟株根际土壤皆以鞘氨醇单胞菌属（Sphingomonas）、芽单胞菌属（Gemmatimonas）为优势属，但随着海拔升高，患病烟株根际土壤和健康烟株根际土壤间前者的相对丰度差距减少，后者的相对丰度差距则进一步加大。（4）生防菌B.amyloliquefaciens F11菌剂可有效控制烟株的青枯病病情，以发病初期施用效果最佳,且其土壤微生物群落的丰富度及多样性与健康土壤（H）处理趋于相似，说明发病前期施用F11菌剂可能有利于土传病害区土壤微生物生态的修复，该生防菌或可有助于构建减缓发病中土壤微生物群落结构的变化的抑病性土壤。