Study Of Diversity And Spatial Distribution Of Soil Nematodes In The Rhizosphere Of Tomato In Solar Greenhouse

The continuous cultivation of tomato in the solar greenhouses in Liaoning Province is very common.Changes of soil nematodes in rhizosphere of tomato,especially the accumulation of plant pathogenic nematodes,affecting the yield and quality of tomato.Therefore,the community characteristics and temporal-spatial distribution of soil nematodes in rhizosphere of tomato in solar greenhouses are important for effectively control of tomato nematode diseases.In this study,171 soil samples were collected in various regions of Liaoning Province from 2016 to 2018.The species diversity of parasitic nematodes in the samples was identified,and the temporal and spatial distribution of soil nematode communities in tomato soil in solar greenhouse was studied.Our study cleared that there were 12 main types of plant parasitic nematodes in tomato roots in different greenhouses in Liaoning Province: M.incognita,Tylenchorhynchus mashhoodi,Tylenchorhynchus ewingi,Tylenchorhynchus annulatus,Pratylenchus coffeae,Filenchus hamatus,Filenchus vulgaris,Pararotylenchus jiaohensis,Rotylenchus calvua,Helicotylenchus dihystera,Aphelenchoides agarici.The M.incognita is more common and found in the all the greenhouses.It is an important plant pathogen and has great harm to tomato.The M.incognita was identified in all soil samples.In this present study,we investigated in a greenhouse in Tieling,Liaoning province,samples were collected during pre-plant period,fruit bearing period,and maturing period in 0~10,10~20,20~30 cm soil depth respectively.The results showed soil nematodes belong to 14 families,30 genera.Among these genera,Meilodogyne,Rhabditis,Protorhabditis were the dominating genera,and plant parasitic nematodes were the dominating nematodes in all sample time.Principal component analysis and interaction analysis found that: in temporal distribution,maturing period was the peak period of the number of soil nematode community;In spatial distribution,the closer to center of the greenhouse,the number of root knot nematode were much high.Significant difference was observed between H ?and GR in the pre-plant period of tomato;significant differences were also found between H ?,J ?,?,GR,MI,PPI and WI,H ?and GR in fruit bear period in different soil layers;only EI was significantly higher in the 10 cm soil layer than in the 30 cm in the maturing period of tomato,and there was no significant difference in other ecological indices,which indicating the soil nematodes communities were abundant in pre-plant period and fruit bear period;however,due to the radical increase of root-knot nematode which caused significant differences in EI,also resulted in a relatively simple food web structure in the mature period.This study clarified the species of plant parasitic nematodes in the rhizosphere of tomato in solar greenhouses in various regions of Liaoning Province,and further proved that the main pathogen was M.incognita,which also revealed the soil nematode community in the greenhouse.The dominant genus was Meloidogyne in spatial distribution.Our study can provide the basic insights of soil nematode ecology and theoretical support for the prevention and control tomato root-knot nematode disease.