Identification Of Longidoridae Nematodes From Imported Seedlings At Ningbo Port

During2011to2012, several Longidoridae nematodes were intercepted from soil or mediums collected from imported seedlings in the process of plant quarantine at Ningbo Port. The economic importance of several important virus-transmitting species in Longidoridae family make them being ranked as the plant quarantine pests in China. In this study, the morphological, morphometric and molecular identifications were carried out for these intercepted longidorids in order to provide technical support in plant quarantine for preventing the spread from China.Total6species were identified, including one Longidorus and5Xiphinema species. Among them, L. martin, X. rivesi, and X brevicollum were plant virus-transmitting species and belonged to plant quarantine pests. L. martin and X. rivesi were intercepted at first time at port in China.The identified L. martini were isolated from Japanese acer palmatum. The identified Xiphinema americanum-growp speices included X. rivesi intercepting from Italian mediterranean cedar tree and apple tree, X. brevicollum from Japanese podocarpus and acer palmatum, X. himalavense from Japanese podocarpus and X. pachtaicum from Italian white oak. The non Xiphinema americanum-group species X. hunaniense was collected from Japanese podocarpus, camellia sasanqua and acer palmatum.Molecular identification was carried out for6Longidoridae species. The28S-D2/D3,18S and ITS1region of rDNA were PCR amplified from all species and6,4and4fragments were finally obtained respectively. All products were purified and sequenced. All sequences were blasted with those closely related species submitted in NCBI GenBank and phylogenetic trees were constructed by Neighbour-joining method. The phylogenetic tree based on sequences of28S-D2/D3of rDNA from Longidorus species confirmed the identification of L. martini. The phylogenetic trees based on sequences of ITSI and28S-D2/D3of rDNA from Xiphinema species revealed that the phylogeny relationships of5Xiphinema species were closed to their morphological characters.