PGPR与外生菌根菌互作对樟子松促生作用及根际微生态环境的影响

PGPR interacts with ectomycorrhizal fungi to promote growth of Pinus sylvestnis var.mongolica and to effect of rhizosphere microecological environment

【目的】研究根际益生菌互作对植物促生及土壤微生态环境的影响,为开发植物促生抗逆作用的生物菌肥提供理论基础。【方法】在盆栽条件下,对樟子松苗木接种假单胞杆菌Pseudomonas fluorescens1-42和褐环乳牛肝菌Suillus luteus N94,采用高通量测序技术、比色法、火焰光度计法等测定1年生樟子松幼苗生长指标、土壤理化指标和根际微生物多样性指标并研究其变化规律。【结果】1)1-42和N94处理组幼苗生物量同对照组(CK)相比显著增加(P<0.05);1-42处理组相对于N94处理组增加了根长、地径和地下部干质量;N94+1-42处理组的苗高和地上部分干质量相对于N94处理组分别增加了9.73%、5.60%。2)同对照(CK)相比,N94与1-42单接种和复合接种处理均可显著提高樟子松1年生苗根、茎和叶的养分含量(P<0.05)。3)同对照(CK)相比,N94与1-42单接种和复合接种处理均可显著提高樟子松1年生苗根际土壤养分含量(P<0.05);其中N94+1-42复合接种处理效果优于N94与1-42单接种处理(P<0.05)。4)4组土壤样品的细菌、真菌多样性高通量测序分别获得229555103、393991268条优化数据的序列条数,平均长度分别为412.78、256.57 bp。以97%相似度划分,分别得到6009、1001个OTU。4组土壤样品的Coverage指数细菌、真菌群落分别为0.9948~0.9793、0.9995~0.9987;1-42与N94互作的根际土壤细菌物种总数最多,但真菌物种总数差异性不大;N94互作的根际细菌群落多样性最高,而N94和1-42互作会降低真菌群落的多样性,可能是N94在1-42的互作下,生物量增加,挤占了其它真菌的生长空间,使真菌群落多样性降低。【结论】根际细菌和菌根真菌互作可以提高植物的生物量,促进植物生长,改善植物、根际土壤的养分含量,影响根际土壤微生物环境。

【Objective】The effects of rhizosphere probiotics interaction on plant growth promotion and soil microecological environment were studied in annual Pinus sylvestris var.mongolica seedlings.【Method】Under pot experiments,P.sylvestris var.mongolica annual seedlings were inoculated with Pseudomonas fluorescens 1-42 and Suillus luteus N94,and High throughput sequencing,colorimetric method and flame photometer were used to determine the growth indexes,soil physical and chemical index and rhizosphere microbial diversity indexes of annual P.sylvestris var.mongolica seedlings.【Result】1)The biomass of seedlings in groups 1-42 and N94 increased significantly compared with that in the control group(P<0.05).Compared with N94 treatment group,treatment group 1-42 increased root length,ground diameter and dry weight of underground part.Seedling height and leaf stem weight of N94+1-42 group increased by 9.73% and 5.60%,respectively,compared with N94 group.2)Compared with control(CK),single inoculation and combined inoculation of N94 and 1-42 could significantly improve the nutrient index content of roots,stems and leaves of 1-year seedlings of P.sylvestris var.mongolica(P<0.05).3)Compared with control(CK),single inoculation and combined inoculation of N94 and 1-42 significantly increased the soil nutrient index content in the rhizosphere of the 1-year seedling of P.sylvestris var.mongolica(P<0.05);The combined inoculation of N94+1-42 was better than single inoculation of N94 and 1-42.4)High-throughput sequencing of bacterial and fungal diversity of the 4 groups of soil samples obtained sequences of 229555103 and 3939991268 optimized data,with an average length of 412.78 bp and 256.57 bp,respectively.Divided by 97% similarity,6009 and 1001 OTUs were obtained respectively.The Coverage index of 12 soil samples was 0.9948-0.9793 and 0.9995-0.9987,respectively.1-42 and N94 interacted with the most rhizosphere soil bacteria species,but there was little difference in the total number of fungal species.The interaction between N94 and 1-42 resulted in the highest diversity of rhizosphere bacterial communities,while the interaction between N94 and 1-42 reduced the diversity of fungal communities.It may be that the interaction between N94 and 1-42 increased the biomass and occupied the growth space of other fungi,thus reducing the diversity of fungal communities.【Conclusion】The interaction between rhizosphere bacteria and mycorrhizal fungi can increase plant biomass,promote plant growth,improve the nutrient content of plants and rhizosphere soil,and affect the microbial environment of rhizosphere soil.