摘要
【目的】土壤理化性质和微生物群落的差异显著影响玉米根际挥发性有机物(volatile organic compounds,VOCs)的产生和释放。对根际VOCs的深入研究有望为充分挖掘根际生物学潜力和根际调控做出积极贡献。【方法】采集山东德州、河北涞水、河北保定、江西南昌、河南孟津、河南商丘等6个地区的旱地耕层土壤进行为期两个月的玉米盆栽试验,利用顶空固相微萃取联合气相色谱–质谱联用检测技术对根际土壤挥发性有机物进行了分析鉴定,利用实时荧光定量PCR技术对根际细菌和真菌进行了定量分析,利用高通量测序技术对根际细菌16S和真菌ITS进行了测序。【结果】从6个旱地土壤中共检测出44种VOCs,主要是烷烃、烯烃、酯类、胺类、有机酸和芳香类化合物,其中多种化合物与植物或微生物的生长代谢密切相关。胺类化合物NBenzyl-N-ethyl-p-isopropylbenzamide和D-2-Bromolysergic acid diethylamide在6个土壤中均被检出,占总量的54.2%;其次检出最多的是烷烃和烯烃,占总量的31.1%和7.6%。江西南昌土壤释放的VOCs在数量和丰富度上均显著高于其他土壤,且大部分为烷烃和烯烃类化合物;从河北保定土壤中检出了6种特有的有机酸和酯类化合物。供试6种土壤中,河南商丘和河北保定的细菌数量显著高于其他四个地方。南昌土壤真菌数量显著较高,但其细菌数量、丰富度和多样性均显著低于其他土壤。6种土壤中的主要细菌依次为Thaumarchaeota(奇古菌门)、Actinobacteria(放线菌门)、Proteobacteria(变形菌门)、Chloroflexi(绿弯菌门)、Acidobacteria(酸杆菌门)、Firmicutes(厚壁菌门)和Unclassified(未分类门),占总细菌群落的92.1%;主要真菌依次为Ascomycota(子囊菌门)、Basidiomycota(担子菌门)和Chytridiomycota(壶菌门),占总真菌群落的98.3%。绿弯菌门仅在南昌土壤中占绝对优势,而南昌土壤中奇古菌门和变形菌门的相对丰度显著比其他地区少;子囊菌门在6种土壤中均为绝对优势真菌门。玉米根际释放的VOCs数量和丰富度与pH、硝态氮、细菌多样性和真菌多样性呈显著负相关(P<0.05),与铵态氮和真菌数量呈极显著正相关(P<0.01);与主要细菌门中的奇古菌门、变形菌门和酸杆菌门呈显著负相关(P<0.05),与绿弯菌门呈极显著正相关(P<0.01),但是与主要真菌门相关性不显著。【结论】理化性质不同的玉米根际土壤中,微生物群落结构与组成存在显著差异。pH是影响微生物生长的重要因素,酸性土壤中的真菌数量显著高于中性土壤,但是其细菌数量、微生物群落丰富度和多样性均显著小于中性土壤。VOCs的产生和释放受土壤、微生物和植物等众多因素的影响,土壤有机质含量越高、透气性越好、微生物数量越多时,释放的VOCs越丰富。
【Objectives】The soil physicochemical properties and microbial community differences significantly affect the release of volatile organic compounds(VOCs) in the rhizosphere of maize. In-depth study is expected to make a positive contribution to fully exploiting the rhizosphere biological potential and rhizosphere manipulation.【Methods】Soils were collected from the tillage layers of Dezhou, Laishui, Baoding, Nanchang,Mengjin and Shangqiu, and used for a pot experiment. The VOCs emitted from maize rhizosphere were identified using solid-phase microextraction(SPME) fiber and Gas Chromatography–Mass Spectroscopy-RealTime Quantitative(qPCR), and High-Throughput Sequencing technology were used to determine the bacterial and fungal communities.【Results】About 44 VOCs were detected, belonging to alkanes, alkenes, esters,amines, organic acids and aromatics. Many of these compounds were closely related to the growth and metabolism of plants or microorganisms. Two amine compounds, N-Benzyl-N-ethyl-p-isopropyl benzamide and D-2-Bromolysergic acid diethylamide, were detected in all treatments and they accounted for 54.2% of the total.The second and third abundant VOCs were alkanes and alkenes, which accounted for 31.1% and 7.6% of the total.The VOCs in number and richness released in soil from Nanchang were significantly higher than those in soils from the other places, and most of them were alkanes and olefins. Six unique organic acids and esters were detected from Baoding. Among the six soils, the abundances of bacteria in Shangqiu and Baoding were significantly higher than those in others, and the abundance of fungi in Nanchang was significantly higher than those of others, but the abundance, richness and diversity of bacteria in Nanchang were significantly lower than those in other soils. The main bacteria in the six soils were Thaumarchaeota, Actinobacteria, Proteobacteria,Chloroflexi, Acidobacteria, Firmicutes, Phytophthora and Unclassified, they accounted for 92.1% of the total bacterial community. The main fungi were Ascomycota, Basidiomycota and Chytridiomycota, they accounted for98.3% of the total fungal community. Chloroflexi only accounted for an absolute advantage in the soil from Nanchang, and the relative abundances of Thaumarchaeota and Proteobacteria in Nanchang soil were significantly less than those of other soils. Ascomycota was an absolutely dominant fungi in all six soils. The number and richness of VOCs released from rhizosphere of maize were significantly negatively correlated with pH, nitrate nitrogen, bacterial diversity and fungal diversity(P<0.05), and significantly positively correlated with ammonium nitrogen and the number of fungi(P<0.01). The VOCs were significantly and negatively correlated with the relative abundances of Thaumarchaeota, Proteobacteria and Acidobacteria(P<0.05), and positively correlated with the Chloroflexi(P<0.01), while the correlation with the main fungal phylum was not significant.【Conclusions】There are significant differences in microbial community structure and composition among the rhizosphere soils with different physical and chemical properties. pH is an important factor affecting the growth of microorganisms. The number of fungi in acid soil is significantly higher than that in neutral soil, but the number of bacteria, microbial community richness and diversity are significantly lower than that of neutral soil. The production and release of VOCs are affected by many factors such as soil, microbes and plants. The higher the soil organic matter content, the better gas permeability and the larger number of microorganisms, the more abundant VOCs are released.
作者
李艳玲
宋阿琳
卢玉秋
王恩召
唐治喜
刘雄舵
范分良
LI Yan-ling;SONG A-lin;LU Yu-qiu;WANG En-zhao;TANG Zhi-xi;LIU Xiong-duo;FAN Fen-liang(Institute of Agricultural Resources and Regional Planning of CAAS/Key Laboratory of Plant Nutrition and Fertilizer of Ministry of Agriculture,Beijing 100081,China;College of Life Science and Chemistry,Hunan University of Technology,Zhuzhou,Hunan 412007,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2019年第10期1633-1645,共13页
Journal of Plant Nutrition and Fertilizers
基金
国家重点研发计划项目（2016YFD0200109,2016YFD0800707）
国家自然科学基金项目（41571297）
中国农业科学院农业资源与农业区划研究所应急性项目（1610132018108,1610132018107）
