相生和相克间作作物对豌豆根际微生物群落的影响

Microbial community structures in rhizosphere soil of peas intercropped with allelobiosis and allelopathy crops

【目的】解析豌豆与相生和相克作物间作其根际微生物群落的组成,探讨作物间发生相互抑制和协同效应的微生物学机制。【方法】盆栽试验设置4个处理:碗豆间作番茄(PT,相生),间作香葱(PA,相克),单作(PP),以不种植作物的处理为对照。供试土壤为红壤土。作物定植50天时,挖出整株植物,通过抖落法采集根际土壤,基于高通量测序技术比较分析豌豆根际土壤中细菌与真菌群落结构。【结果】间作番茄(PT)处理豌豆根际土壤微生物生物量磷(MBP)显著高于间作香葱(PA)和碗豆单作(PP)。相生或相克组合间作均提高了豌豆植株根际土壤细菌和真菌各分类水平的数量,并且细菌多样性和丰富度均发生显著变化。间作诱导豌豆植株根际土壤细菌和真菌群落组成发生显著变化,间作香葱诱导糖单孢菌属(Saccharomonospora)和硫杆菌属(Thiobacillus)等具有分泌抑制豌豆生长化感物质潜力的细菌,以及作为病原菌的镰刀菌属(Fusarium)真菌富集在豌豆植株根际。与之相比,间作番茄虽然对豌豆根际细菌和真菌群落多样性与丰富度影响较小,但显著改变了豌豆根际细菌和真菌的群落组成;另一方面,豌豆间作相生作物—番茄不仅诱导油壶菌属(Olpidiom)真菌富集,而且降低了镰刀菌属(Fusarium)等病原真菌的相对丰度。【结论】与相生作物间作,可提高豌豆根际土壤中的微生物磷含量;而与相克作物间作,诱导豌豆根系招募分泌抑制豌豆根系生长的化感成分的有害微生物以及致病菌,这可能是作物相克的重要原因。

【Objectives】The microbial community structures in rhizosphere soils of peas were determined under intercropping with mutual generation and constraining crops,to clarify the microbial mechanisms of the allelopathy phenomenon.【Methods】Pea(Pisum sativum L.)was grown under three modes,intercropping mutual generation crop(pea/tomato,PT),mutual constraining crop(pea/chives,PA),and pea monoculture(PP),and the blank soil was also used as a control in the pot experiment.The test soil was red loam.At 50 days of transplanting,whole crops were dig out,and the rhizosphere soil of peas was collected by shaking the root slightly,based on high-throughput sequencing technology,analyzing the soil microbial community structures in rhizospheres of peas.【Results】The microbial biomass P(MBP)of intercropping pea(PT)rhizosphere was significantly higher than that of intercropping(PA)and bowl pea(PP);the combination of phased pea plants increased the number of bacteria and fungi in each species,and the bacterial diversity and richness changed significantly;intercropping induced significant changes in the composition of bacterial and fungal communities in the rhizosphere of pea plants,Saccharomonospora and Thiobacillus,which can secrete the inhibitory substances for pea growth,and the pathogenic microorganisms,such as Fusarium enriched in rhizospheres of peas could be detected under the mutual constraining intercropping system(pea/chives,PA).In contrast,although soil bacterial and fungal diversities and richness in rhizospheres of peas could not be significantly improved,but their compositions were significantly altered by intercropping with mutual generation crops(pea/tomato,PT)which compared to those of intercropping with mutual constraining crops(pea/chives,PA).Additionally,the enrichment of Olpidiom,and the decline of Fusarium in rhizospheres of peas could be found in the mutual generation intercropping system(pea/tomato,PT).【Conclusions】Intercropping with mutual generation crop help the enrichment of beneficial microorganisms,while intercropping with mutual constraining crop helps the enrichement of harmful and disease microorganisms in the rhizosphere soil of peas,which might be an important mechanism of the allelopathy phenomenon of peas intercropping with different crops.