玉米秸秆深翻还田土壤细菌群落16SrDNA-PCR-DGGE分析

以秸秆深翻还田土壤为研究对象，利用嵌套式PCR和DGGE电泳技术对细菌16SrDNA V3～V5区进行扩增和产物分离，分析3个秸秆深翻处理下春玉米各生育期土壤细菌群落变化，探索高寒灌溉农区春玉米秸秆深翻还田中细菌群落结构特征。结果初步表明，秸秆还田处理细菌多样性高于常规旋耕无秸秆还田处理，这种多样性同时受玉米生育期和不同秸秆还田处理的影响。3个处理相同生育期DGGE条带数有明显的变化，玉米秸秆深翻还田两年处理（SF-II）条带数最多，其次是玉米秸秆深翻还田1年处理（SF-I），常规旋耕无秸秆还田（CK）最少；在成熟期，SF-II条带数为12，是CK处理的两倍。玉米全生育期一直存在数种优势菌群，但各时期细菌的种类不同，整体表现为随着玉米的生长细菌种类逐渐增加，成熟期减少。秸秆深翻还田能丰富土壤微生物多样性，玉米生长中期土壤微生物多样性较丰富。

Analysis of the Bacterial Communities in Deep Returning Maize Straw Soils Using 16SrDNA-PCR-DGGE

Straw returning to deep plowing soil as the research object, the amplification and product separation of bacteria 16SrDNA V3-V5 were studied by nested PCR and denaturing gradient gel electrophoresis(DGGE), three straw deep plowing soil bacteria community changes in each growth stage of spring maize in irrigated areas were analyzed. The results indicated that the treatment of straw returning, bacterial diversity was higher than that of conventional tillage with no straw returning treatment, this diversity was also affected by the growth of maize and straw returning treatment. Three processing the same growth period, the number of DGGE bands had obvious changes, the number of SF-II bands of the most, followed by SF-I, the minimum was CK; especially in the mature stage, the number of SF-II bands was 12, two times of CK. Several kinds of dominant bacteria have been found in maize during the whole growing period in the soil; but in different periods of different bacteria, for the overall performance of the growth of maize with bacterial species increased gradually, mature period reduced; straw deep ploughing returning could enrich the soil microbial diversity; maize growth medium soil microbial diversity was rich.