小麦和豌豆填闲对白菜幼苗生长和土壤微生物群落结构的影响OA北大核心CSTPCD

[Objective]This study aimed to investigate the impact of cover crops(wheat and common vetch)on the growth of Chinese cabbage seedlings and the structure of the soil microbial community.The findings could provide the theoretical and technical support for using wheat and common vetch cover crops to alleviate continuous cropping obstacles in Chinese cabbage production.[Method]In this experiment,there were four treatments:wheat cover crop treatment(W),common vetch cover crop treatment(P),mixture of wheat and common vetch treatment(WP),and no cover crop treatment(CK).The effects of different cover crop treatments on the growth of Chinese cabbage seedlings were studied.Moreover,the effects of wheat and common vetch cover crops on the microbial community of Chinese cabbage rhizosphere were also investigated through qPCR and Illumina MiSeq techniques.In addition,Spearman correlation analysis was conducted to identify the key soil microbial taxa related to Chinese cabbage growth.Then,the changes in soil chemical properties on soil microbial community structure were explored by environmental factor correlation analysis.[Result]Compared with CK,the cover crop treatments had positive effects on Chinese cabbage growth and decreased soil electrical conductivity(EC)value.The mixed cover crop treatment significantly decreased soil available potassium content,whereas wheat cover crop treatment increased soil pH.The qPCR results showed that the abundance of soil bacterial community was not significantly affected by the cover crop treatment,but increased the abundance of soil fungal community.Both common vetch cover crop treatment and mixed wheat and common vetch cover crop treatment significantly reduced the abundances of Bacillus spp.and Pseudomonas spp.communities.The Illumina MiSeq analysis showed that the relative abundance of genus TM7a was significantly increased by cover treatments,while the relative abundances of Leptolyngbya_EcFYyyy-00,Lophotrichus,Acaulium,and Sodiomyces were decreased.The mixed cover crop treatment significantly increased the relative abundance of Sphingomonas and Massilia and significantly decreased the relative abundance of Fusarium.Spearman correlation analysis showed that Sphingomonas,TM7a,Massilia,and Gemmatimonas were positively correlated with growth.Leptolyngbya_EcFYyyy-00,Acaulium,Lophotrichus,Sodiomyces,and Fusarium were significantly negatively correlated with the growth of Chinese cabbage.Moreover,these cover crop treatments influenced bacterial and fungal diversity indices.The Shannon index and inverse Simpson index for soil bacterial community and Shannon index of soil fungal community significantly decreased in cover common vetch treatment.In contrast,the inverse Simpson index of soil fungal community was increased.The mixed cover crop treatment increased the fungal Shannon index,while the inverse Simpson index of soil fungal community decreased.Principal Coordinates Analysis(PCoA)showed significant differences in soil microbial community structure,with soil EC value as a major environmental factor affecting the structure.[Conclusion]The cover crop treatments exhibited growth-promoting effects on Chinese cabbage seedlings,and the best effect was found in the mixed cover crop treatment.The relative abundances of some Sphingomonas,TM7a,Massilia,other potential growth-promoting bacteria were increased in the cover crop treatments.The relative abundances of some potential plant pathogens Leptolyngbya_EcFYyyy-00 and Fusarium were decreased and the relative abundance of potential biocontrol agent Chaetomium was increased in the mixed cover crop treatment.