Identification Of Pratylenchus Species Intercepted At Chinese Ports

During 2012 to 2013, several Pratylenchus populations were intercepted from imported plant seedlings, plant tissues and soil media at Ningbo, Beijing, Shenzhen and Zhejiang Ports. These root lesion nematodes can cause serious damage to root systems and play important role in international trade and are ranked as the plant quarantine pests in China. In this study, the morphological and molecular identifications were carried out for these intercepted populations in order to provide technical support for Chinese plant quarantine services.Total 9 populations were intercepted and identified as 8 Pratylenchus species. At Ningbo Port, P.japonicus and P. vulnus were isolated from root system of Acer palmatum imported from Japan, P. loosi was from Japanese Camellia sasanqua and P. penetrans from Dutch Lilium hybrids. At Beijing Port, P. bolivianus was isolated from New Zealand Phormium tenax and P. pseudopratensis was from plant soil taken along with a Russia flight passenger. P. coffeae was isolated from Colocasia esculenta taken along with a Hongkong flight passenger at Shenzhen Port. P. hippeastri was intercepted from posted Japanese Acer palmatum and imported Israel Hippeastrum vittatum by Zhejiang Port and Ningbo Port, respectively. Four species, including P. bolivianus, P. hippeastri, P.japonicus and P. pseudopratensis, were intercepted first time in China.The 28S D2/D3 domain, ITS,18S region of ribosomal DNA (rDNA) and COI region of mitochondrial DNA (mtDNA) were PCR amplified for 9 Pratylenchus populations. All products were sequenced and in total,9 sequences for 28S D2/D3 region,5 for ITS region, 4 for 18S region and 3 for COI region were obtained. All sequences were blasted in NCBI GenBank and phylogenetic trees were constructed on basis of 28S-D2/D3 and ITS sequences by Neighbour-joining method. The phylogenetic analysis revealed consistent conclusion with those from morphological identification.