红壤坡地利用方式对土壤细菌群落结构的影响

SOIL BACTERIA COMMUNITY STRUCTURE IN UPLAND RED SOIL IN RELATION TO LAND USE PATTERN

利用中国科学院桃源农业生态试验站坡地不同利用方式长期定位观测试验场农田、自然恢复和茶园土壤为研究对象,直接从土壤中抽提总DNA,应用T-RFLP和RT-PCR技术研究红壤坡地利用方式对土壤细菌群落结构的影响。结果表明,红壤坡地三种土地利用方式土壤细菌多样性指数农田>茶园>自然恢复(p<0.05),但土壤细菌数量茶园>自然恢复>农田(p<0.05),茶园土壤细菌数量是农田的8.76倍。基于T-RFLP图谱的样品间相似性指数和主要限制性片段(T-RFs)定性分析均表明,农田与茶园和自然恢复土壤均存在显著的差异(p<0.05),而茶园和自然恢复土壤细菌群落比较相似。不同土地利用方式土壤有机质、有效磷和速效钾均对土壤细菌群落结构产生显著影响(p<0.05)。综合考虑经济效益和保持红壤坡地的可持续利用,茶园将成为中国南方红壤丘陵坡地可持续利用的一种有效方式。

Total soil microbial DNA was directly extracted from soils of farmland（F）,tea garden（T） and natural forest（G） at the Taoyuan Agro-ecosystem Research Station and soil bacteria community structures of the soils were analyzed with the technology of T-RFLP and RT-PCR amplified 16S rRNA gene fragments.It was found that the bacterial diversity index or Shannon index followed the order of farmland〉 tea garden〉 natural forest（p〈0.05）,while the population of soil bacteria did the order of tea garden 〉natural forest 〉farmland（p〈0.05）,and the highest（tea garden） was 8.76 times as much as the lowest（farmland）.The analysis based on the similarity values using Jaccard＇s coefficient and T-RFLP profiles by PAT T-RFLP program showed that soil bacteria community structure was significantly different between farmland and the other two,but was quite similar between tea garden and natural forest.The analysis of chemical properties of the soils showed that Olsen-P,available K and SOC were the major factors distinctly affecting soil bacteria community structures in those soils under different land-use.Taking economy and ecology into account,tea garden should be a sustainable land use pattern for upland red soil in China.