A molecular phylogenetic approach for unravelling the taxonomic status of Basilaphelenchus persicus n. gen., n. sp. (Aphelenchoididae: Tylaphelenchinae)

Abstract

SummaryBasilaphelenchus persicusn. gen., n. sp. is described and illustrated based on morphological and molecular phylogenetic studies. The new genus belongs to the family Aphelenchoididae and is characterised mainly by the small body size of females (297-393 μm) and males (304-331 μm), high cephalic region in both sexes, fine 5.5-7.8 μm long stylet that is barely visible in mounted specimens yet clear in fresh individuals, stylet with a linear conus and weak shaft ending in three elongate, posteriorly directed, knobs, small spherical metacorpus with posteriorly located (at 72-75% of metacorpus) weak but distinct valve, monodelphic-prodelphic reproductive system with a long post-vulval uterine sac containing large rounded sperm cells, a vulva lacking any flap apparatus, conical tail of female usually ventrally bent at tip and male tail ventrally bent as in the female, lacking the P1 supplement, but with three pairs of caudal papillae, and small arcuate spicules with rounded condylus and small pointed rostrum. The new genus is similar to bothTylaphelenchusandPseudaphelenchusin the possession of a raised cephalic region and a small spherical metacorpus, placing it in the subfamily Tylaphelenchinae. It is also typologically similar toAphelenchoides. Molecular phylogenetic studies using both SSU and LSU rRNA gene sequences (both partial) revealed that the new genus formed a robustly supported sister clade withPseudaphelenchusspp. and had a basal placement to this clade and, probably, to all other aphelenchoidids.Tylaphelenchus grosmannaeis transferred to the new genus asB. grosmannaen. comb. andA. christinaen. comb. (= T. christinae) is proposed. The taxonomic status ofTylaphelenchusis discussed andT. sinodendronin. comb. (= A. sinodendroni) proposed.