土壤抑真菌作用与细菌群落结构的关系

自然清洁土壤所具有的抑真菌作用，是健康土壤的一种自然属性，也是土壤质量的重要指标之一，对控制农作物土传病原真菌的爆发具有积极的生态学意义.本试验以中国科学院沈阳生态实验站近10年未受农药和肥料影响的撂荒地土壤作为自然清洁土壤样品，通过高温（对照、100 ℃、110 ℃、121 ℃）处理得到具有不同抑真菌作用的土壤模型，采用PCR DGGE(变性梯度凝胶电泳)方法对上述土壤样品的细菌群落结构进行分析.结果表明：土壤抑真菌作用与土壤细菌群落结构紧密相关；对照清洁土壤抑真菌作用最强，处理后土壤细菌群落结构偏离自然清洁土壤愈远，土壤抑真菌能力愈差；DGGE特异性条带切胶测序结果表明，Sphingomonas asaccharolytica、Nitrospira sp.、Hyphomicrobiaceae sp.、Bacillus megaterium和Micrococcus sp.可能与土壤抑真菌作用密切相关.

Relationship between soil fungistasis and bacterial community structure.

As a natural attribute of clean and healthy soil, fungistasis is an important indicator of soil quality, and has positive ecological significance to the inhibition of plant disease eruption caused by soil-borne fungal pathogens. In this study, soil samples (0-15 cm) were collected from the abandoned land at Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, to which pesticides and fertilizers have never been applied for nearly 10 years. A series of soil samples with gradient fungistasis was obtained by heating (CK, 100 degrees C, 110 degrees C, and 121 degrees C for 4 min, respectively), and bacterial community structure was analyzed by Polymerase Chain Reaction coupled with Denaturing Gradient Gel Electrophoresis method (PCR-GGGE). The results showed that there was a significant correlation between soil fungistasis and bacterial community composition. Treatment CK showed the strongest capacity to control the growth of target soil-borne pathogenic fungi. The further the bacterial community structure of treated soil deviated from that of CK, the lower the soil fungistasis was. Sequencing and the following phylogenetic analysis of special bands in DGGE indicated that Sphingomonas asaccharolytica, Nitrospira sp., Hyphomicrobiaceae sp., Bacillus megaterium, and Micrococcus sp. could be involved in soil fungistasis.