Identification Of Plant Parasitic Nematodes From Imported Seedlings,Horticultural Plants And Wood Packaging

During the general plant quarantine for imported plant seedlings and horticultural plants together with their mediums,and wood packaging,several plant parasitic nematodes were intercepted at Ningbo,Guangxi and Guangdong Port.These nematodes have the potential for causing serious damage to agricultural crops and forestry in China.In order to provide taxonomical information,support the plant quarantine techniques,and prevent the invasion of these dangerous pests,the morphological and molecular identifications were carried out in this study.Total seven populations of plant parasitic nematodes were intercepted from three Chinese Ports.Through morphological identification and morphometric characters comparison,three populations of cyst nematode intercepted at Ningbo Port were identified.The population from rhizosphere of Japanese Acer palmatum was identified as Heterodera elachista,the populations from Japanese Podocarpus macrophyllus,one was identified as Cryphodera brinkmani,another one was identified as an unknown species of Cryphodera.One Xiphinema population intercepted from Thailand horticultural plants at Guangxi Port was identified as X.brasiliense which is a member of the non X.americanum group species,another population intercepted from imported Japanese seedlings P.macrophyllus at Ningbo Port was identified as an unknown species of Xiphinema.One Bursaphelenchus population isolated from imported packaging wood materials from Taiwan at Guangdong Port was identified as B.gillanii,another one isolated from imported packaging wood from Singapore at Ningbo Port was identified as an unknown species Bursaphelenchus.Both Bursaphelenchus species belong to the xylophilus group.The phylogenetic analyses based on sequences of 28S-D2/D3,ITS and 18S region of ribosomal DNA for these intercepted populations revealed their close relationships between phylogeny and taxonomic status.The molecular characteristics strongly supported the morphological identification.The populations of H.elachista,B.gillanii and three unknown species were intercepted first time in China.