耕作制度对甘薯地土壤线虫群落结构的影响

 【目的】通过研究不同耕作制度对甘薯地土壤线虫群落结构的影响，探索以土壤线虫为指示生物评价不同耕作制度下甘薯地土壤健康状况的敏感指标。【方法】试验中对不同耕作制度下土壤线虫群落Shannon多样性指数、SR指数、J指数、成熟度指数及土壤线虫群落相似性指数进行分析。【结果】连作甘薯地极优势属为植物寄生茎线虫属（Ditylenchus），轮作、休闲状态下极优势属为头叶线虫属（Cephalobus）、真头叶线虫属 （Eucephalobus），滑刃（Aphelenchoides）和真滑刃线虫属（Aphelenchus）。连作甘薯和轮作玉米地同一土层线虫属数量间没有显著差异，线虫数量间有显著差异。连作使PPI、PPI/MI值增高，WI、∑MI、MI值降低，轮作可使PPI、PPI/MI值降低WI、∑MI、MI值增高。【结论】不同耕作制度改变土壤线虫群落在土壤剖面的垂直分布，∑MI指数、MI指数、PPI 和PP /MI值、WI值可作为甘薯地土壤健康评价的敏感指标，相似性指数可反映不同耕作制度下土壤线虫群落间相似及相异程度。

Effect of Cropping Systems on Nematode Community Structure in Sweet Potato Field

Different cropping system was conducted to study the nematode diversity structure and Similarity index .Soil nematodes as bioindicators was used to evaluate different cropping system on soil health. The results indicated that Ditylenchus the dominant genera in Continuous cropping , Cephalobus, Eucephalobus, Aphelenchoides, Aphelenchus was the dominant genera in rotation. Thel number of nematodes category has singificant differences between different soil layer during the study period, but the total number of nematodes was not. Continuous cropping system reduce the WI、 、MI. increase of PPI、PPI/MI indxs. rotato can reduce number the PPI、PPI/MI, increase number of WI、 、MI indxs； 、MI 、PPI and PP /MI、WI indxs the to evaluate different planting modes soil health seneitive indicators.