Molecular and morphological characterisation of Aphelenchoides kheirii n. sp. (Nematoda: Aphelenchoididae) isolated from Pinus nigra in north-western Iran

Abstract

Summary Aphelenchoides kheirii n. sp. was isolated during a survey of nematodes associated with bark samples of pine trees (Pinus nigra) in West Azerbaijan province, north-western Iran. The new species has a body length of 500 (448-520) μm in the female and 442 (402-480) μm in the male. The cuticle is weakly annulated with four lateral lines and the lip region is offset. The stylet is 10.4 (10-11) μm long with small basal swellings and the excretory pore located immediately posterior to base of metacorpus; hemizonid invisible. The post-vulval uterine sac length 37.7 (28-45) μm. Spicules are relatively short (18-20 μm in dorsal limb) and the end of the dorsal limb clearly curved ventrally like a hook. The male tail has usual three pairs of caudal papillae (2 + 2 + 2) and a well-developed mucron. The female tail is conical, terminating in a complicated step-like projection, usually with many tiny nodular protuberances. The new species belongs to the Group 2 category of Aphelenchoides species sensu Shahina in which ten known species among Groups 2 and 4 sensu Shahina, namely: A. arcticus, A. blastophthorus, A. fuchsi, A. parasaprophilus, A. paraxui, A. xui, A. dactylocercus, A. gynotylurus, A. iranicus and A. saprophilus are the most similar species. Phylogenetic analysis based on small subunit (SSU) and partial large subunit (LSU) sequences of rRNA supported the morphological results.