Classification And Identification Of Major Nematode Species Occurring On Root And Tuber Crops In Fujian,China

During March,2016 to August,2017,the survey on nematode of Ginger(Zingiber officinale),Yam(Dioscorea opposita)and Taro(Colocasia esculenta)were carried out in Fujian province,and the key nematodes of the crops were identified,The results would have an important significance for sustainable development of nematode diseases of the crops.The results were as follows:1.The major pathogenic nematodes on ginger were identified,and Meloidogyne enterolobii infecting ginger was the first record in China.Two species of root-knot nematodes were collected from roots of ginger in Fujian province,Based on morphological characteristics,and molecular characters by sequencing the mitochondrial DNA region between COII and the lrRNA genes,rDNA-ITS?28S D2-D3 region,the species were identified as M.incongnita and M.enterolobii.the species identity was further explored by phylogenetic trees derived from Maximum Likelihood and Bayesian analysis based on CO? and the lrRNA genes,rDNA-ITS?28S D2-D3 region.The pathogenicity of M.enterolobii on ginger were confirmed in a glasshouse test.To our knowledge,this is the first record of M.enterolobii parasitizing a plant(i.e.,ginger)in the family Zingiberaceae in China.Due to the wide host range,highly pathogenic,The more attention and inspection should given to the emerging nematodes.In addition,Rotylenchulus reniformis from ginger root were identified by using morphological identification and molecular character.2.Pratylenchus coffeae and Tylenchorhynchus annulatus were confirmed as major pathogenic nematodes on taro in Fujian.Two species of nematodes were collected from root and tuber of taro in Fujian province.Based on morphological characteristics,and molecular characters by sequencing the rDNA-ITS and 28S D2-D3 region,the species were identified as P.coffeae and T.annulatus.this is the first record of T.annulatus parasitizing taro in China.P.coffeae is commonly distributedin taro planting areas and gave serious damage in Fujian Province.3.Meloidogyne incongnita was the most widespread and economically important species on yam:Five species of nematodes isolated from root and tuber of yam in Fujian province were identified as M.incongnita,Helicotylenchus dihystera,Rotylenchulus reniformis and Hemicriconemoides strictathecatus based on morphological characteristics and molecular characters.M.incongnita is the most important pathogenic nematode on yam.Thy sypmtoms of infected tuber of yam by M.incongnita were surface cracking and brown nodulated,brown,discolored,necrotic tissue beneath.4.The major pathogenic nematodes on Alocasia macrorrhiza were identified,and Pratylenchus brachyurus infecting Alocasia macrorrhiza was the first record in China.The nematodes were collected from roots of Alocasia macrorrhiza in Fujian province.Based on morphological characteristics and molecular characters by sequencing the rDNA-ITS,28S D2-D3 region,the species were identified as P.brachyurus.P.brachyurus is a quarantine pest in China and should be given enough attention.