Morphological and molecular charaterisation of Pratylenchus parazeae n. sp. (Nematoda: Pratylenchidae) parasitizing sugarcane in China

A new root-lesion nematode was isolated from sugarcane (Saccharum sinensis Roxb.) in Guangxi Zhuang Autonomous Region, China. Morphology and molecular analyses of rRNA small subunit (SSU), D2D3 expansion domains of large subunit (LSU D2D3) and internal transcribed spacer (ITS) confirmed that this nematode is different from other previously described root-lesion nematodes. Herein it is described, illustrated and named as Pratylenchus parazeae n. sp. This new species is characterised by plain and smooth En face, three lip annuli, stylet with anteriorly rounded to indented knobs, 17.0–19.0 μm long, lateral field composed of four lines with areolated outer bands at vulval region, vulva position 68.9–74.9 %, small, oval and empty spermatheca, and a subhemispherical tail usually with smooth terminus and sometimes with a more or less pronounced dorsally indented terminus. Phylogenetic trees inferred from BI analysis based on SSU, LSU D2D3 and ITS revealed that P. parazeae n. sp. can be distinguished from all described root-lesion nematodes, especially from the most closely related species P. zeae. A species-specific duplex PCR was also developed to separate the new species from other nematode species.