Study On The Mechanism Of Allium Fistulosum L.root Exudates To Relieve The Replant Disease Of Grape

Replant disease seriously restricts the healthy development of the grape industry.Intercropping is one of the effective methods to alleviate the replant disease.In order to clarify its mechanism,the effective intercropping crop Allium fistulosum L.was screened out in the previous stage,and this experiment use it as a test material to analyze the effects of Allium fistulosum L.root exudates on the microbial structure,function and pathogens of rhizosphere soil of grape?Vitis.riparia?.At the same time,the composition of the root exudates of Allium fistulosum L.was analyzed using metabolomics technology,the composition of the root exudates of Allium fistulosum L.was analyzed,and the effective antifungus ingredients were screened out.The main results are as follows:1.Allium fistulosum L.root exudates significantly promote the growth of plant height.The addition of Allium fistulosum L.root exudates in sterilized and unsterilized soil significantly increased the dry weight of the plants;In unsterilized soil,the root exudates of Allium fistulosum L.also significantly increased the fresh weight of above ground and dry weight of below ground;2.Microbiological sequencing results showed that the addition of Allium fistulosum L.root exudates changed the microbial community in the rhizosphere soil of grape plants,significantly increased the relative abundance of the bacteria of the genus Neorrizobium,Shinella,Devosia,Chitinophaga,and Hydrogenophaga in the rhizosphere soil;Significantly reduced the relative abundance of Rhodosporidiobolus,Ilyonectria,Penicillium,Stachybotrys,Cystobasidium,Naganishia,and Wallemia fungi;3.The inhibition effect of Allium fistulosum L.root exudates on soil pathogenic Fusarium was clarified,and the maximum inhibition rate was 33.50%at the concentration of0.5 g·m L^-1;4.Non-targeted metabolomics analysis of the Allium fistulosum L.root hydroponic solution,a total of 22368 items of data were detected,of which 157 metabolites can be clearly classified.Among them,the largest proportion is organic acids and their derivatives,there are 42 compounds of this type,accounting for 26.75%.When they are classified according to their class,the largest proportion is carboxylic acids and their derivatives,there are 34 compounds of this type,accounting for 21.66%.When they are classified according to their material structure,the largest proportion is aliphatic acyclic compounds,there are 68compounds of this type,accounting for 43.32%;5.Further experiments investigated the components of the Allium fistulosum L.root exudates,4-hydroxycinnamic acid,L-pyroglutamic acid,and dimethylbenzimidazole,on the growth of the harmful fungi Fusarium and the beneficial bacteria Pseudomonas.The results showed that L-pyroglutamic acid had the best inhibitory effect on the growth of Fusarium mycelium,and dimethylbenzimidazole had the strongest promotion effect on the growth of Pseudomonas.