Description of two new records of genus Longidorus (Nematoda: Dorylaimida) in China

Abstract

Two new recorded species of genus Longidorus (L. pius and L. diadecturus) were recovered and collected from rhizosphere of deciduous trees in Hangzhou of Zhejiang Province and Wuhan of Hubei Province, China, respectively. Morphological identity was confirmed using the revised polytomous key of Loof & Chen, 1999. The codes for identifying the species of L. pius and L. diadecturus are A56-B4-C3-D1-E1-F3-G1-H1-I1 and A4-B23-C5-D3-F2-G2-H1-I1, respectively. L. pius was characterized by medium body size (L=4.7-6.3 mm), anterior region abruptly tapering with rounded lip continuous from body profile, odontostyle long (130-143 μm) and short rounded tail. Meanwhile, L. diadecturus could be distinguished by short body size (3.2-4.6 mm), short odontostyle (108-120 μm), posterior position of guide ring (33-38 μm), wide lip region and a relatively anterior vulva. Phylogenetically, the rDNA internal transcribed spacer 1 (ITS1) region of L. pius from China showed 99% supported clade with L. pius topotype (AM743178) from Macedonia, and the similar relationship was obtained in L. diadecturus from China with 99% well supported clade to L. diadecturus type population (AF511416) from Canada. In addition, the 28S region of L. diadecturus from China showed 99% supported clade with L. diadecturus type specimen (AY601584), whereas L. pius noticeably clustered to L. raskii (AJ549983) and Longidorus sp. FDL-2011 (FR775757). The two species, L. pius and L. diadecturus were recorded for the first time in China, and the morphological description and phylogenetic relationships of the given species were provided in this study.