毛莲英 李海碧 桂意云 张荣华 杨荣仲 周会 韦金菊 刘昔辉

摘要：【目的】探究甘蔗間作猫豆对甘蔗根际土壤微生物多样性的影响，为改善甘蔗根际土壤微生物群落结构及促进甘蔗生长提供理论参考。【方法】采用单因素试验设计，分析单作甘蔗（CK）和甘蔗间作猫豆（T处理）2种种植方式对甘蔗根际土壤养分的影响，并采用Illumina HiSeq高通量测序技术，在门和属水平上分析甘蔗根际土壤微生物群落结构，在种水平进行主成分（PCA）分析。【结果】T处理的根际土壤中全氮、全钾、水解性氮、有效磷和有机质含量均大于CK。T处理的根际土壤中细菌的丰富度和多样性高于真菌的丰富度和多样性;T处理的根际土壤中细菌丰富度高于CK，但差异不显著（P>0.05，下同），其多样性显著高于CK（P<0.05，下同）;T处理的根际土壤中真菌的丰富度和多样性均显著高于CK。CK和T处理土壤样品的主要优势细菌门为变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、绿弯菌门（Chloroflexi）和酸杆菌门（Acidobacteria），其相对丰度均大于10.00%，优势细菌属分别为水恒杆菌属（Mizugakiibacter）、游动四孢属（Luedemannella）、乳杆菌属（Acidothermus）和布氏杆菌属（Bryobacte），但T处理根际土壤样品中水恒杆菌属、游动四孢属和乳杆菌属的相对丰度分别较CK下降2.47%、1.78%和0.68%，其他细菌属分别增加0.10%～0.86%。CK和T处理根际土壤中优势真菌门为子囊菌门（Ascomycota），分别为80.00%和92.00%，其次是担子菌门（Basidiomycota），分别为8.00%和6.00%，排名前3的优势真菌属均为戴氏霉属（Taifanglania）、毛壳属（Chaetomium）和镰刀菌属（Fusarium）。CK和T处理的6份根际土壤样品在种水平上的主成分（PCA）分析结果显示，细菌群落PC1的变异为29.37%，PC2的变异为20.26%，二者的总贡献率为49.63%;真菌群落PC1的变异为33.44%，PC2的变异为27.73%，二者的总贡献率为56.17%。CK与T处理的细菌群落分别属于不同象限，CK位于第1和第3象限，而T处理位于第2和第4象限。【结论】甘蔗间作猫豆可改善甘蔗根际的土壤养分状况，改变甘蔗根际微生物的群落结构，提高细菌和真菌的丰富度和多样性，但未影响优势菌门的排序。

关键词： 甘蔗;猫豆;间作;根际;土壤微生物;高通量测序;群落结构

中图分类号： S556.106.1                               文献标志码： A 文章编号：2095-1191（2021）02-0332-09

Abstract：【Objective】The effects of Mucuna pruriens var. utilis intercropping with sugarcane on the microbial diversity in the rhizosphere of sugarcane were investigated，and a theoretical foundation was laid for improving the soil microbial community structure of M. pruriens intercropping with sugarcane and promoting the growth of sugarcane. 【Method】A single-factor design experiment was conducted to analyze the microbial community structure of sugarcane rhizosphere soil at the phylum and genus levels by Illumina HiSeq high-throughput sequencing technology under the two planting methods of sugarcane monoculture（CK） and sugarcane intercropping M. pruriens（T treatment），and principal component analysis （PCA） to determine the effect of intercropping M. pruriens on sugarcane rhizosphere soil nutrients. 【Result】The contents of total nitrogen，total potassium，hydrolyzable nitrogen，available phosphorus and organic matter in rhizosphere soil of T treatment were higher than those of CK treatment. The richness and diversity of bacteria in the rhizosphere soil of T treatment was higher than that of fungi. The bacterial richness of  bacteria in the rhizosphere soil of Ttreatment was higher than that of CK，but the difference was not significant（P>0.05， the same below）， its diversity was significantly higher than that of CK（P<0.05， the same below）. The abundance and diversity of bacteria in the rhizosphere soil under T treatment were significantly higher than that of CK.The dominant phylum of bacteria in CK and T treatments were Proteobacteria，Actinobacteria，Chloroflexi and Acidobacteria，and their relative abundances were more than 10.00%. The dominant bacteria genera were Mizugakiibacter，Luedemannella，Actinothermus and Bruyobacte，but the relative abundances of Mizugakiibacter，Luedemannella，Actinothermus decreased by 2.47%， 1.78% and 0.68%， other bacteria increased by 0.10%-0.86% compared to CK under T treatment.  The dominant fungal phyla in the rhizosphere soil of CK and T treatments was Ascomycota，80.00% and 92.00% respectively，followed by Basidiomycota，8.00% and 6.00%，the top three dominant fungi genus all belonged to the genus Taifanglania，Chaetomium and Fusarium. Principal component analysis（PCA） of six root soil samples treated with CK and T showed that the variation of bacterial community PC1 was 29.37%，the variation of PC2 was 20.26%，the total contribution rate of both was 49.63%; the variation of fungal community PC1 was 33.44%，the variation of PC2 was 27.73%，the total contribution rate of both was 56.17%. The bacterial communities of CK and T treatment belonged to different quadrants，respectively，CK was located in the 1st and 3rd quadrants，and T treatment was located in the 2nd and 4th quadrants. 【Conclusion】The results show that intercropping sugarcane with M. pruriens improves the soil nutrient status，changes the microbial community structure，and increases the richness and diversity of bacteria and fungi in sugarcane rhizosphere， but does not affect the sequence of dominant microflora.

Key words： sugarcane; Mucuna pruriens var. utilis; intercropping; rhizosphere; soil microbe; high-throughput sequencing; community structure

Foundation item：National Natural Science Foundation of China（31860350）; National Sugar Industry Technology System Project（CARS-170105）; Central Guides Local Project（Guike ZY20198005）; Basic Research Project of Guangxi Academy of Agricultural Sciences（Guinongke 2021YT006）

0 引言

【研究意义】甘蔗（Saccharum officinarum）为全球重要的糖类和能源作物，是种植行距较宽的作物，目前种植行距多为1.2 m，常与生长快速的作物间作或与生长期短的作物套种可有效改善土壤酶活性，提高土壤微生物数量和多样性，充分提升养分利用效率及经济效益（张爱加等，2013;彭东海等，2014;沈雪峰等，2014）。猫豆为一年生豆科黎豆属草质藤本植物，多分支，根系较发达，叶蔓攀高，覆盖面广，有利于保持水土，其根部富含根瘤菌，可有效提高土地肥力（秦祖臻等，2012;韦道鞍，2013;李经成等，2016），适合与其他作物间种。土壤微生物多样性不仅代表微生物群落的稳定性，同时还反映土壤的生态机制和土壤胁迫对微生物群落的影响，是导致微生物代谢方式和生理功能多样化的直接原因（彭东海等，2014;张晟等，2019）。因此……