不同连作年限对马铃薯根际土壤中AM真菌的多样性.docVIP

DOI: 10.13930/ki.cjea.140888 马铃薯连作栽培对土壤微生物多样性的影响( 马 玲 马 琨** 张楠楠 代晓华 (宁夏大学农学院 银川 750021) 摘 要 阐明连作对土壤微生物类群结构功能的影响, 揭示连作障碍机制用BIOLOG技术结合AM真菌形态学鉴定方法连作的马铃薯田块结果表明: 土壤养分含量随连作年限增加有一定程度的下降, 连作10年马铃薯根际土壤的全磷、速效磷、速效钾和碱解氮与连作4年相比分别下降7.36%、61.32%、26.66%和17.24%但没有明显的养分亏缺和不均衡现象。土壤微生物群落结构发生了较大变化, 放线菌、真菌数量显著增加, 呈单峰变化趋势; 细菌数量呈逐步减少趋势4-6年下土壤微生物群落依然有较强的功能多样性培养120 h后, 连作6年较之迎茬AWCD值提高了3.89%; 群落组成中以碳水化合物、羧酸类化合物为碳源的微生物类群代谢能力明显下降, 代谢功能多样性趋于一致。连作马铃薯土壤AM真菌优势种改变迎茬时为沙荒球囊霉(G deserticola)，连作2年时为和福摩萨球囊霉Glomus delhiense, Glomus formosanum), 连作10年时为球泡球囊霉Glomus globiferum)。土壤微生物结构与功能多样性、AM真菌多样性变化受土壤pH、全磷影响, 放线菌、细菌数量和土壤中可利用碳水化合物、胺类化合物的微生物类群影响。长期连作栽培会土壤真菌、放线菌的数量; 真菌群落中AM真菌种的多样性显著下降, 优势种发生改变打破微生物群落结构与功能平衡，引起土壤微生物群落结构与功能的失调， 关键词 连作 根际土壤微生物 AM真菌 微生物群落结构与功能 中图分类号: S154.3 Effect of potato continuous cropping on soil microorganisms diversity MA Ling, MA Kun, ZHANG Nannan, DAI Xiaohua (School of Agriculture in Ningxia University, Yinchuan Ningxia, 750021, China) Abstract The soil in potato continuous cropping 0, 2, 4, 6, 10 years were studied to explain the continuous cropping obstacle mechanism by adopting the BIOLOG technology combined with morphological identification method of AMF. The results showed: The soil nutrient content dropped in a certain degree along with continuous cropping years, the total phosphorus, abailable phosphorus, available potassium and the available nitrogen decreased 7.36%、61.32%、26.66%和17.24% when compared with 4 years, but no obvious phenomenon of nutrient deficiency and nutrient unbalance. The microbial community structure changed a lot, showing the actinomyces, fungi number increased first and then droped significantly along with the years-a unimodal type trend; and bacteria decreasd. Soil microorganism in 4-6 years showed a strong microbial functiongal diversity, the AWCD in 6 years was higher 3.89% than 0 year. The ability for using the carbon compunds and carboxy componds has dropped and the carbon source ultilization type turned the same along with the continuous cro