施氮和间作花生对木薯根际土壤细菌群落结构的影响

Effects of nitrogen application and intercropping with peanut on bacterial community structure in cassava rhizosphere soil

在等量施肥条件下,木薯间作一季花生,是否具有间作优势,间作模式中木薯根际土壤细菌群落结构如何变化,相关研究报道较少。以木薯品种"华南205"、花生品种"粤油200"为试验材料,设计施氮、不施氮2个处理和等量施肥条件下的3种种植模式(木薯单作、花生单作、木薯间作花生),采用高通量测序技术,研究施氮和间作花生对木薯根际土壤细菌群落结构的影响。结果表明,在等量施肥条件下,木薯-花生间作的土地当量比大于1,表现出间作优势。施氮和间作花生对木薯根际土壤细菌的多样性无显著影响。4个优势细菌门类依次为绿弯菌门、变形菌门、放线菌门和酸杆菌门。不同处理间的菌门Saccharibacteria的差异极显著,施氮显著降低了疣微菌门的相对丰度。木薯根际土壤细菌的属数量共464个。相对丰度排名前30的菌属中,不同处理间菌属Acidobacteriaceae__Subgroup_1_和Sphingomonas的差异达显著或极显著水平,施氮显著降低了菌属Subgroup_7的相对丰度,显著提高了菌属Acidothermus的相对丰度。主成分分析表明,施氮对细菌群落组成的影响大于种植模式;冗余分析得出,有机质、pH值显著影响细菌属水平群落组成。

Under the condition of equal amount fertilization,whether cassava intercropping with one season peanut has the intercropping advantage or not,and how the bacterial community structure of cassava rhizosphere soil changes in the intercropping pattern,little related research on these questions are reported.Using cassava variety“South China 205”and peanut variety“Yueyou 200”as experimental materials,designing two levels as with nitrogen application and without nitrogen application,and three planting patterns(cassava mono-cropping,peanut mono-cropping,cassava intercropping with peanut)under the conditions of equal amount fertilization,an experiment was designed to analyze the effect of cassavapeanut intercropping and nitrogen application on the bacterial community structures in cassava rhizosphere soil in Jiangxi province based on high-throughput sequencing techniques.The results showed that under the condition of equal fertilization,the land equivalent ratio of cassava-peanut intercropping was more than 1,showed the intercropping advantage.Nitrogen application and intercropping with peanut had no significant effect on the diversity of bacteria in cassava rhizosphere soil.The four dominant bacteria were Chloroflexi,Proteobacteria,Actinobacteria and Acidobacteria in turn.The difference of Saccharibacteria among different combinations of nitrogen application and planting patterns was extremely significant.Nitrogen application significantly reduced the relative abundance of Verrucomicrobia.There are 464 bacteria genera in the rhizosphere cassava soil.Among the top 30 genera in relative abundance,the difference of Acidobacteriaceae__Subgroup_1_and Sphingomonas among different combinations of nitrogen application and planting patterns was significant or extremely significant.Nitrogen application significantly reduced the relative abundance of Subgroup_7 and increased the relative abundance of Acidothermus.Planting patterns had no significant effect on the relative abundance of soil bacteria in cassava rhizosphere.The bacterial community structure of cassava rhizosphere soil under the condition of equal amount fertilization was studied to provide a theoretical basis for clarifying the rhizosphere microecology of cassava in intercropping pattern.Principal component analysis showed that the effect of nitrogen application on bacterial community composition was greater than that of planting pattern.Redundancy analysis showed that organic matter and pH significantly affected the composition of bacterial horizontal community.