Identification Of Aphelenchoides Species From Imported Packaging Wood, Dead Pine Trees And Rhizosphere Of Plants

Bursaphelenchus xylophilus is a world wide important pest, which leads to great damage to conifer trees by causing pine wilt disease to pine trees. And it is an important quarantine pest of China. During survey and research of dead pine trees, many other Aphelenchoides species were discovered, besides of B. xylophilus. More and more new Aphelenchoides species were reported ever since. Therefore, the morphorlogical, morphometric and molecular identifications were carried out for 11 Aphelenchoides populations isolated from packaging wood imported at Ningbo Port, dead pine trees infested with B. xylophilus and rhirosphere of plants at production base of exported vegetable, which lays a foundation for further study of the influence of these Aphelenchoides species on trees and plants.The populations isolated from packaging wood originated from Austrailia, German, Korea and South Africa were preliminarily identified as A. unisexus, the populations from dead Pinus thunbergii in Dalian and Nanjing were as A. dalianensis and the population from rhizosphere of potatos were as A. sacchari. One population isolated from the packaging wood from South Africa was identified as a new species of Aphelenchoides and the morphological and morphometrics characters were described. Moreover,3 other Aphelenchoides populations isolated from P. thunbergii in Changdao of Shandong Province, P. massoniana in Guangde of Anhui Province and rhizospheres of purple ipomoea batatas in Lianyungang of Jiangsu Province were described but the taxonomic status were not confirmed.ITS region of rDNA and D2/D3 region of 28S from the isolated populations of Aphelenchoides species were amplified. The PCR products were purified and sequenced. Total 9 sequences of ITS region and 10 sequences of D2/D3 region of 28S were abtained. All sequences were blasted with those submitted in Genbank and phylogenetic trees were constructed based on ITS and D2D3 sequences, respectively. The phylogenetic analysis relvealed that all 11 populations were grouped with other Aphelenhoides species. The results obtained from phylogenetic analysis were consistented with those from morphological identification.