应用454测序技术分析种植制度对黑垆土微生物多样性的影响

摘要

It has important significance on optimizing dryland cropping systems, mining the soil potential fertility and achieving the sustainable use of soil resources that we study the influence of cropping systems on soil microbial diversity in typical arid areas. In the long-term experiment lasted 27 years, we analyzed the diversity changes of bacteria and fungi in black loessial soil under different cropping systems in Loess Plateau using 454 sequencing technology. The results showed that bacterial diversity showed wheat-pea rotation>continuous wheat>fallow land>continuous alfalfa, and fungal diversity showed continuous wheat≈continuous alfalfa>fallow land>wheat-pea rotation under low nutritional stress with no fertilization. In the conditions of application of nitrogen fertilizer and phosphorus fertilizer, microbial diversity generally showed an decreasing and then increasing trend in long-period rotation of wheat–alfalfa (alfalfa→alfalfa→alfalfa→alfalfa→potato→wheat→wheat→wheat, eight years as a rotation period); Chao index and Shannon index of the 4th year alfalfa or the 1st year wheat were the lowest, and those of the 2nd year wheat were the maximum, with the bacteria Chao index and fungi Shannon index of 22.0% and 79.2% higher than those of continuous wheat, respectively. Microbial diversity generally showed an increasing trend in short-period rotation of wheat–sainfoin (sainfoin→wheat→wheat, three years as a rotation period), and that of the 2nd year wheat after sainfoin was the maximum, with fungi Chao index and Shannon index of 50.8% and 51.0% higher than that of continuous wheat respectively. Wheat-forage legumes rotation could improve the microbial diversity significantly in Loess dryland areas.%研究典型种植制度对旱地黑垆土微生物多样性的影响，对优化旱地作物种植制度、发挥土壤潜在肥力、实现土壤资源可持续利用有着重要的意义。通过27年长期定位试验，采用454测序技术分析了黄土高原旱作地区不同种植制度下黑垆土细菌、真菌多样性的变化情况。结果表明，不施肥低营养胁迫下，细菌多样性表现为粮豆轮作>小麦连作>裸地>苜蓿连作，真菌多样性表现为小麦连作≈苜蓿连作>裸地>粮豆轮作。施氮、磷肥条件下，粮草长周期轮作(苜蓿→苜蓿→苜蓿→苜蓿→马铃薯→小麦→小麦→小麦+苜蓿)中土壤微生物多样性大致表现出先降低后增加的趋势，第4年苜蓿或苜蓿茬后第1年小麦微生物 Chao 指数和 Shannon 指数最低，苜蓿茬后第2年小麦微生物多样性最高，细菌 Chao 指数和真菌 Shannon 指数比连作小麦高22.0%和79.2%；粮草短周期轮作(红豆草→小麦→小麦+红豆草)中土壤微生物多样性大致呈现增加趋势，至红豆草茬后第2年小麦土壤微生物多样性达到最高，真菌 Chao指数和 Shannon 指数均分别比连作小麦高50.8%和51.0%。黄土高原旱地区黑垆土采取粮食作物与豆科作物轮作可提高土壤微生物多样性。