Investigation And Identification Of Soil Nematodes Species In Hainan Province

Soil nematodes are the most abundant group in soil animals,and have a great impact on agricultural production and soil ecology.The unique geographical location and good ecological environment of Hainan Province have enriched the abundance of biotic populations,however,systematic study on soil nematodes diversity in Hainan Province is rarely carried out.In this study,a total of 150 soil samples were collected from different regions and habitats in Haikou,Sanya,Wenchang,Wanning,Dongfang,Chengmai,Lingshui,Changjiang,Nansha Islands and Xisha Islands of Hainan Province,and nematodes were extracted and identified.The main results are as follows:1.In this study,a total of 8 orders,23 families,41 genera and 29 species of soil nematode were identified.Among them,1 new records of genera(Sporonchulus)and 7 new records of species(Mesocriconema ornatum,Eudorylaimus diadematus,Chiloplacus tenius,Rhabditis drosophilae,Chronogaster Spinicauda,Wilsonema otophorum,Monochus aquaticus)were identified in China;3 new records of families(Pseudodiplogasteroidoidae,Rhabdolaimidae,Tripylidae),14 new records of genera(Gracilacus,Mesocriconema,Calcaridorylaimus,Discolaimium,Discolaimus,Mesodorylaimus,Microdorylaimus,Pseudacrobeles,Pseudodiplogasteroides,Rhabdolaimus,Mylonchulus,Tripylina,Eumonhystera,Geomonhystera)and 14 new records of species(Flienchus hamatus,Rhabdotylenchus guangdongensis,Ditylenchus myceliophagus,Hirschmanniella areolata,Helicotylenchus abunaamai,H.australis,Scutellonema brachyurus,Quinisulcius capitatus,Gracilacus goodeyi,Aphelenchus isomerus,Aphelenchoides variacaudatus,Xiphinema brevicolle,Mesodorylaimus boluoensis,Acrobeles complexu)were identified in Hainan Province.2.The results explicated that Rotylenchulus,Helicotylenchus,Tylenchorhynchus,Pratylenchus,Meloidogyne and Aphelenchus were the dominant populations of plant parasitic nematodes in Hainan Province.Dorylaimida,Rhabditida and Areaolaimida were dominant populations of free-living nematodes in Hainan Province.3.This study preliminarily explicated the main groups of soil nematodes in different regions and habitats of Hainan.The nematodes in the crop field soil samples are majorly included Rotylenchulus,Helicotylenchus,Ditylenchus and Aphelenchoides,and a small number of free-living nematodes,such as Rhabditida,Dorylaimida,Areaolaimida.The nematodes in the non-crop field soil samples,i.e.grass lands,roadside trees and wind tungs etc.in Nansha and Xisha Islands,are mainly free-living nematodes,i.e.Cephalobidaes,Dorylaimidae,Rhabditidaandae,Areaolaimidae,and a small number of Mononchidas,Monhysteridas and Enoplidas.In addition,it is common to identify out some plant parasitic nemaotdes,such as Rotylenchulus,Helicotylenchus,Meloidogyne and Aphelenchus etc..In the non-plants covered area in the Nansha and Xisha Islands,it is characterized by single species and small number of nematodes,dormainted by Rhabditida,Dorylaimida,and Areaolaimida,and ralely seen Monhysteridas,however,plant parasitic nematodes,such as Rotylenchulus,Quinisulcius and Aphelenchus were found too.In conclusion,in this study,systematic study of soil nematodes in Hainan province was carried out,and the results not only provide more species diversity information of soil nematodes in Hainan,but also enrich the resources of soil nematodes in China.In addition,the results provide a scientific basis for the prevention,quarantine and monitoring of plant nematode diseases,and is also very important for protecting the plant production trade and ecological environment in the Hainan Province.