摘要
【背景】栀子为多年生常绿灌木,经过连续多年种植会导致土壤微生态环境恶化、病虫害加剧、品质降低等问题。研究发现间作可以改善土壤微生物区系、土壤养分及酶活性,是生产中常用的有效栽培措施。【目的】通过对不同间作模式下栀子根际土壤微生物区系、酶活性及养分的动态变化进行研究,为揭示栽培措施改良土壤生态环境及提升栀子产量的土壤微生态学机理提供理论依据。【方法】为了解不同间作模式对栀子根际微生态的影响,本试验选择3年生栀子进行了大田试验,采用随机区组设计,设置栀子单作及栀子/白及、栀子/金钱草、栀子/射干3种间作处理,以栀子根际土壤为研究对象进行全生育期取样。采用Illumina高通量测序技术测定细菌16S rRNA基因V3-V4区序列及真菌rDNAITS1-ITS2区序列,并测定各时期土壤的理化性质,以明确栀子间作不同作物对其根际微生物群落及土壤理化性质随栀子生育期的动态变化。【结果】在栀子整个生育过程中,根际细菌群落中变形菌门和酸杆菌门的相对丰度分别为39%和18%,为细菌优势菌门。真菌群落中子囊菌门、担子菌门和被孢霉门相对丰度所占比例依次为51%、22%和19%,为主要真菌类群。在果实膨大期,与单作栀子相比,栀子/射干和栀子/白及可以显著增加土壤细菌群落Shannon指数,增幅分别为6.55%和3.45%(P<0.05),其他时期差异不显著。盛花期,栀子/射干间作不会显著降低根际真菌的多样性,而与金钱草或白及间作则显著降低其多样性;果实膨大期,栀子/射干和栀子/白及间作均可以显著提高根际土壤真菌群落的Shannon指数,增幅分别为29.19%和9.12%。土壤养分方面,不同间作模式下根际土壤理化性质存在一定差异。单作栀子根际土壤仅有机质、全氮、速效磷的含量较高,而碱解氮、速效钾含量均低于3种间作处理。土壤酶方面,单作栀子除酸性蛋白酶外,其余几项土壤酶活性均处偏下水平。土壤理化性质与根际微生物多样性的相关性分析显示,细菌多样性指数Shannon与根际土壤有机质、速效磷含量呈显著正相关,与pH值呈极显著正相关(P<0.01);真菌多样性指数Shannon与根际土壤全钾、脲酶、过氧化氢酶呈极显著负相关,与速效钾、蔗糖酶、酸性磷酸酶、酸性蛋白酶活性呈极显著正相关。【结论】合理间作可以改善根际微生物群落结构,同时提高土壤综合肥力。
[Background] Gardenia jasminoides Ellis is a perennial evergreen shrub. After years of continuous planting, it will lead to deterioration of the soil micro-ecological environment, aggravation of pests and diseases, and reduced quality. It was found that intercropping was an effective cultivation method in production to improve soil microflora, nutrient and enzyme activity. [Objective] In this study,the dynamic changes of the rhizosphere soil microflora, enzyme activity and nutrients of gardenia under different intercropping patterns were studied, in order to provide a theoretical basis for revealing the soil microecology mechanism of cultivation measures to improve the soil ecological environment and enhance the yield of gardenia. [Methods] To understand the effects of different intercropping patterns on the rhizosphere microecology, three-year-old gardenias were selected for field experiment. Random block design was adopted. Gardenia single cropping and Gardenia/Bletilla striata, Gardenia/Lysimachia christinae, Gardenia/Belamcanda chinensis three intercropping treatment were set, using Gardenia rhizosphere soil as the research material, sampling throughout the growth periods. Illumina high-throughput sequencing technology was used to determine the sequences of bacterial 16 S rRNA gene V3-V4 and fungal rDNA ITS1-ITS2, and the physical and chemical properties of the soil in each period were determined, so as to clarify the intercropping of different crops on the gardenia rhizosphere microbial community and soil physical and chemical properties with the growth period. [Results] In the whole growth process of gardenia, the relative abundance of Proteobacteria and Acidobacteria in the rhizosphere bacterial community were 39% and 18%, respectively, which were the dominant bacteria. In the fungal community, the relative abundance of Ascomycota, Basidiomycota and Mortierellomycota accounted for 51%, 22% and 19%, respectively, which were the main fungal groups. In the fruit expansion stage,compared with single cropping, Gardenia/Belamcanda and Gardenia/Bletilla striata can significantly increase the Shannon index of soil bacterial communities by 6.55% and 3.45%(P<0.05), respectively, but there was no significant difference at other stages. In terms of rhizosphere fungi, Gardenia/Belamcanda does not significantly reduce the diversity during the full blooming period, while intercropping with Lysimachia or Bletilla will significantly decrease;In the fruit expansion stage, Gardenia/Belamcanda and Gardenia/Bletilla intercropping can significantly increase the Shannon index of the rhizosphere soil fungal community by 29.19% and 9.12%, respectively. In terms of soil nutrients, The contents of organic matter,total N and available P in rhizosphere soil of gardenia monoculture were higher, while the contents of alkaloid N and available K were lower than the three intercropping treatments. In terms of soil enzymes,except for the acid protease, the activities of the other soil enzymes of the single-cropped gardenia are at a lower level. Correlation analysis between soil physical and chemical properties and rhizosphere microbial diversity showed that the bacterial diversity index Shannon was significantly positive correlated with rhizosphere soil organic matter, available P, and extremely significantly positive correlated with pH(P<0.01);The fungal diversity index Shannon was significantly negative correlated with total K, urease and catalase in rhizosphere soil, and significantly positive correlated with available K, sucrase, acid phosphatase, and acid protease activities. The comprehensive scores of soil fertility in the blooming stage and fruit expansion stage showed that the soil fertility scores of Gardenia/Belamcanda was the highest, and that of Gardenia/Lysimachia was the lowest. [Conclusion] Reasonable intercropping can improve the microbial community structure in the rhizosphere, and improve the comprehensive soil fertility. The soil fertility comprehensive score of Gardenia/Belamcanda is the highest, they may be the desirable intercropping patterns for Gardenia cultivation.
作者
李巧玲
肖忠
任明波
韩凤
胡开治
LI Qiaoling;XIAO Zhong;REN Mingbo;HAN Feng;HU Kaizhi(Chongqing Institute of Medicinal Plant Cultivation,Bio-Resource Research and Utilization Joint Key Laboratory of Sichuan and Chongqing,Chongqing 408435,China)
出处
《微生物学通报》
CAS
CSCD
北大核心
2021年第10期3588-3602,共15页
Microbiology China
基金
国家重点研发计划(2017YFC1700704)
重庆市科研院所绩效激励专项(cstc2018jxjl-jbky80002)。
关键词
栀子
间作模式
根际微生物
土壤酶活性
土壤养分
Gardenia jasminoides Ellis
intercropping pattern
rhizosphere microorganisms
soil enzymatic activity
soil nutrient