复合功能菌群的构建及其对铅锌胁迫下蓖麻种子萌发和铅锌积累的影响

Construction of microbial consortium and its effects on seed germination and lead-zinc accumulation of Ricinus communis L. under lead-zinc stress

为了研究复合菌群对铅锌胁迫下蓖麻种子萌发的影响,以期为下一步微生物-蓖麻联合修复盆栽实验提供功能菌群和理论基础,从课题组内经菌肥改良后的植物根际土壤中筛选出根际促生菌,与课题组已有的菌株进行平板拮抗实验,优选测序并构建复合菌群。沙培实验考察复合菌群对铅锌胁迫下种子萌发的影响,收获后分别测定其萌发生长指标、扫描其根系形态、测定重金属富集量,并对其结果进行分析。筛选出了具有溶磷能力的真菌L14为尖孢镰刀菌Fusarium oxysporum,且与实验室两株耐性菌HA、J3构建的复合菌群相互无拮抗。该复合菌群接种到基质后,能在高浓度重金属胁迫下有效促进蓖麻种子萌发及幼苗生长,同时促进其根系对重金属的富集。其中,对Pb的累积量最大可提升38.6%,对Zn的累积量最大可提升25.2%。分析结果表明:该复合菌群在铅锌胁迫下不仅能够促进蓖麻种子萌发及幼苗生长,还可以显著提高幼苗根系对重金属的吸收累积。

In order to investigate the effects of lead-zinc resistant microbial consortium on seed germination of Ricinus communis L. which would be used to construct a functional microbial consortium for the further study ofRicinus communis L.-microbial remediation. The screened rhizospheric microorganisms in microbial fertilizer improved rhizosphere soil were carried out a plate antagonism test with the preserved strains in our laboratory for a gene sequence analysis to construct the functional microbial consortium. Moreover, a pot experiment of the seed of Ricinus communis L. under lead-zinc stress was conducted to analyze the effect of the germination percentage, growth indicators, heavy metal accumulation, and the root morphologyon the inoculation of microbial consortium. The obtained phosphate-solubilizing fungi L14 was identified as Fusarium oxysporum. There is nonantagonistic effect among the microbial consortium composed by the screened fungi and the preserved 2 strains （HA, J3） strains in our laboratory. After inoculating into substrate, the microbial consortium can effectively promote seed germination and seedling growth ofRicinus communis L. under heavy metal stress of a high concentration. Meanwhile, the maximum accumulation of heavy metal in root can be increased by 38.6% for Pb as well as 25.2% for Zn. The microbial consortium not only could promote seed germination and seedling growth, but also obviously improve the root accumulation of heavy metal in Ricinus communis L. seedling under lead-zinc stress.