轮作年限对大蒜根际土壤微生物群落的影响

Effects of Rotation Years on Rhizosphere Soil Microbial Communities of Garlic

采用传统平板计数法、PCR-DGGE及Biolog技术,研究大蒜/黄豆单一模式轮作体系下轮作年限（2,8,15,20,30年）对大蒜根际土壤微生物数量、结构及功能多样性的影响。结果表明：随着大蒜/黄豆单一模式轮作年限的增加,大蒜根际土壤细菌数量与微生物总量均降低,而真菌和放线菌增加;轮作年限越长,大蒜根际土壤微生物群落结构相似性越低,轮作种植2-30年,其相似性由87%下降至77%,轮作种植2年和8年其群落结构相似性最高,达87%;轮作年限的过度延长也显著降低大蒜根际土壤微生物群落的功能多样性,轮作种植8年和30年分别是大蒜根际土壤微生物群落整体功能活性的最高点和最低点;长期大蒜/黄豆单一模式轮作是大蒜连作障碍的重要原因,轮作年限不宜超过15年,8年左右是改变单一轮作种植模式的最佳时期。

The effects of different rotation years（2,8,15,20,30years）on rhizosphere soil microbial communities amount,structure and function diversity of garlic were conducted in the garlic/soybean singlemode rotation system by the traditional plate count method,PCR-DGGE and Biolog techniques.The results showed that,with the increase of the garlic/soybean single-mode rotation years,the amount of rhizosphere soil bacteria and total microbial of garlic decreased and the amount of fungi and actinomyces increased.The extension of rotation years reduced the similarity of rhizosphere soil microbial community structure of garlic,the similarity decreased from 87% under 2 rotation years to 77% under 30 rotation years.The 87% similarity of rhizosphere soil microbial community structure of garlic between 2 rotation years and 8 rotation years was the highest.The extension of rotation years decreased the function diversity of rhizosphere soil microbial community of garlic significantly.The overall rhizosphere soil microbial community functional activity of garlic under 8 rotation years and 30 rotation years was the highest point and the lowest point respectively.Long-term garlic/soybean single-mode rotation was responsible for the garlic successive cropping obstacles.The rotation years of the garlic/soybean single-mode should not exceed 15 rotation years.The best time to change the garlic/soybean single-mode rotation system was 8 rotation years.