Suitability Risk Assessment For Six Potential Invasive Nematodes In China

Suitability risk assessment for six potential invasive nematodes in China AbstractDitylenchus destructor,Heterodera schachtii,Globodera rostochiensis,Globodera pallida, Aphelenchoides ritzemabosi,Radopholus similis are all the pathogenic nematode on crops and widely distributed.So far,they have been discovered in part or not discovered in China.Therefore,it is of important significance in theory and application for risk assessment,potential distribution prediction and proposal of risk management measures in China.In this paper,based on our collected documents and its basic bio-ecology characteristics,CLIMEX was used to predict the potential distribution area of Ditylenchus destructor.we combined the results of CLIMEX with the spatial interpolating function of Geographical Information System(GIS),which is able to transform the point data into area data.Through the overlay function of GIS,non-agricultural factors were primarily considered.This made the prediction results further accurately.According to the values of ecoclimatic index (EI),we divided the potential suitable area into four categories.Using the MAXENT to predict the distribution of Ditylenchus destructor further,the prediction result of MAXENT is the same as the area penetrated,therefore,we determined the suitable area based on the result of MAXENT and CLIMEX for a reference.GARP and MAXENT were also used to predict the distribution of Heterodera schachtii,Globodera rostochiensis,Globodera pallida,Aphelenchoides ritzemabosi,Radopholus similis.We also considered the impact of nonagricultural factors on the distribution.Suitable areas were defined based on the results of MAXENT and GARP for a reference.The high and middle risk areas of potato rot nematode were concentrated in northern China, especially north of China,mostly northeast of China,and Shandong,north of Hubei,north of Anhui,Shanxi, Ningxia,southeast ofGansu.The potential distribution region will be 32°N～48°N,104°E～128°E.H.schachtii will distribute in 17 provinces in China at least,the high risk areas including south of Inner Mongolia,west of Xinjiang,south of Hebei,northeast of Shanxi,Ningxia,north of Gansu.The potential distribution region in China will be 26°N～48°N,77.6°E～136°E.The vast areas in China may be suitable for Globodera rostochiensis.The high and middle areas range from 24°N～40°N,including Heilongjiang,Jilin,Liaoning,Hebei,Shandong,Shannxi,Shanxi,Henan, Anhui,Jiangsu,Hubei,Hunan,Jiangxi,Sichuan,Chongqing,Yunnan,Guizhou.The potential distribution area of Globodera pallida was concentrated in southwest of China,Including Yunnan,Guizhou,Sichuan, Chongqing,Guangxi,Hainan,Jiangsu.Most areas in China were suitable for Aphelenchoides ritzemabosi,Except for south of Xinjiang,north of Inner Mongolia,north of Heilongjiang,The high risk areas were centered on the south of China.The potential distribution of R.similis should be constricted within the south of China.The northern boundary of natural spread may reach Henan,Shandong.The high risk areas range from 18.5°N～24°N. The endangered areas of the six quarantine nematodes were given,the results provided technical supports for the national sanitary and phytosanitary policy-making.