微生物型育苗垫片对水稻根围土壤微生物多样性的影响

Effects of microbial seedling-raising compressed paper on rice soil microbial diversity

[目的]分析微生物型育苗垫片对水稻根围土壤微生物多样性和群落组成的影响,为微生物型育苗垫片的示范应用提供科学参考。[方法]采用水稻秧盘育苗试验,基于常规微生物培养和高通量测序技术测定微生物型垫片育苗对水稻根围土壤微生物种群数量、多样性及群落组成变化。[结果]与普通壮秧剂育苗相比,微生物型垫片育苗的水稻根围土壤细菌数量在出苗后第7 d增加了36. 59%,第14 d和第21 d时降低但差异不显著;放线菌数量分别显著增加了271. 11%、702. 48%和100%;真菌数量在第7 d和第14 d分别降低了127. 05%和740%,第21 d时明显增加了160. 98%。在水稻幼苗根围微生物群落组成中,变形菌门、放线菌门、酸杆菌门和螺旋体菌门为优势细菌,子囊菌门、担子菌门、接合菌门和壶菌门为优势真菌;与对照相比,微生物型育苗垫片组中变形菌门增加,螺旋体菌门和酸杆菌门减少,其中高丰度的假单胞菌属、根瘤菌属、节杆菌属、克雷伯氏菌属等根围促生菌均为水稻幼苗根围优势菌;真菌的子囊菌门增加,担子菌门、接合菌门和壶菌门减少,后期子囊菌门成为单一优势菌,该门的腐质霉属、假裸囊菌属和接合菌门的被孢霉属菌为优势菌。[结论]微生物型垫片育苗在水稻幼苗前期可提高土壤细菌的丰富度,后期降低土壤真菌的丰富度和多样性,具有改善水稻幼苗根围微生态环境的作用。

[Objective]To provide basis for the demonstration and application of microbial seedling-raising compressed paper(MSP)by investigating the effects of MSP on rice soil microbial diversity and composition.[Method]Based on conventional microbial culture and high-throughput sequencing technology,the role of MSP on population,composition and structure of microbial communities of rice soil was studied.[Result]Compared with the ordinary seedling-strengthening agent,the number of bacteria in MSP group increased by 36.59%on 7 d of rice emergence,and then decreased slightly on 14 d and 21 d.The number of actinomycetes increased by 271.11%,702.48%and 100%respectively,while the number of fungi decreased by127.05%and 740%on 7 d and 14 d respectively,and increased by 160.98%on 21 d.Among the diversity of rhizosphere microbial community of rice seedlings,Proteobacteria,Actinobacteria,Acidobacteria and Saccharibacteria were dominant bacteria,while Ascomycota,Basidiomycota,Zygomycota and Chytridiomycota were dominant fungi.Among them,high abundance of rhizosphere growth-promoting bacteria such as Pseudomonas,Rhizobium,Arthrobacter and Klebsiella were dominant rhizosphere bacteria in rice seedlings.The Ascomycota of fungi increased,Basidiomycota,Zygomycota and Chytridiomycota decreased,and Ascomycotabecame single dominant fungi at the last stage,its Humicola,Pseudogymnoascus and the Mortierella of Zygomycota were the dominant fungi.[Conclusion]With the usage of microbial seedling-raising compressed paper,the richness of soil bacteria can be increased in the early stage of rice seedling,while the richness and diversity of soil fungi can be decreased in the later stage of rice seedling.It can improve the rhizosphere microecological environment of rice seedlings.