日光温室番茄不同生育期根围土壤线虫空间分布研究

Diversity and Spatial Distribution of Rhizosphere Soil Nematodes in a Tomato Greenhouse during Different Growing Period

番茄在我国日光温室中连作栽培现象非常普遍,其根围土壤线虫的变化尤其是植物病原线虫的积累影响番茄的产量和品质,因此,明确日光温室番茄根围土壤线虫的群落特征和时间空间分布对有效控制番茄线虫病害具有重要意义。对辽宁省铁岭市日光温室番茄土壤线虫群落和时间空间分布进行研究,分别在番茄定植前期、盛果期和成熟期,定点采集0～10,10～20,20～30cm深度土壤样本135份。结果表明:共鉴定土壤线虫14科30属,其中根结线虫属(Meloidogyne)、小杆属(Rhabditis)和原杆属(Protorhabditis)为优势属,植物寄生线虫营养类群在番茄整个生育期都是优势营养类群;利用Graphpad Prism和Canoco的主成分分析和交互分析发现,时间上番茄成熟期为土壤线虫群落数量的高峰期,番茄盛果期和成熟期根结线虫属的线虫数量占据绝对优势。空间上靠近日光温室中心点处,根结线虫属的线虫数量最多;番茄定植前期不同土层深度间香农-威纳多样性指数(H′)和丰富度指数(GR)差异性显著,番茄盛果期不同土层深度间香农-威纳多样性指数(H′)、均匀度指数(J′)、优势度指数(λ)、丰富度指数(GR)、自由生活线虫成熟度指数(MI)、植物寄生线虫成熟度指数(PPI)和瓦斯乐斯卡指数(WI)差异性显著,番茄成熟期只有富集指数(EI)在0～10cm土层中显著高于20～30cm土层,其他生态指数差异不显著,说明番茄定植前期和盛果期土壤线虫群落多样性相对比较丰富,但成熟期由于根结线虫的激增使EI指数差异明显,食物网结构较单一。通过揭示日光温室番茄土壤线虫群落和优势属根结线虫属的时空分布,为番茄根结线虫病害的防控提供理论支持。

It is a common phenomenon that continuous cultivation of tomato in solar greenhouse.Changes of soil nematodes in the root zone of tomato,especially the accumulation of plant parasitic nematodes,affect crop yield and quality heavily.Therefore,figuring out the spatial distribution of soil nematodes in greenhouseis meaningful to control PPNs.In this present study,we conducted an investigation in a greenhouse in Tieling,Liaoning province,135soil 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 that 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 the whole growth period.Principal component analysis and interaction analysis by using Graphpad Prism and Canoco software found that:intemporal distribution,maturing period was the peak period of soil nematode community;in spatial distribution,near the center of the greenhouse,the number of root knot nematode was hightest.Significant differenceswereobserved between H′and GR in the pre-plant period of tomato;significant differences were also found among H′,J′,λ,GR,MI,PPI and WI,H′and GR in fruit bear period in different soil layers;only EI was significantly higher in the 0-10 cm soil layer than that in the 20-30 cm in the maturing period of tomato,and there was no significant difference in other ecological indices,which indicatedthat the soil nematodes communities were abundant in pre-plant period and fruit bear period;however,the radical increase of root-knot nematode caused significant difference in EI,and also resulted in a relatively simple food web structure in the mature period.This study revealed thatthe temporal and spatial distribution of soil nematode communities and dominating genus Meloidogyne in greenhouse,which couldcertainly provide theoretical guidance for controlling root-knot nematode disease of tomato.