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

Abstract

Summary Basilaphelenchus persicus n. 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 both Tylaphelenchus and Pseudaphelenchus in the possession of a raised cephalic region and a small spherical metacorpus, placing it in the subfamily Tylaphelenchinae. It is also typologically similar to Aphelenchoides. Molecular phylogenetic studies using both SSU and LSU rRNA gene sequences (both partial) revealed that the new genus formed a robustly supported sister clade with Pseudaphelenchus spp. and had a basal placement to this clade and, probably, to all other aphelenchoidids. Tylaphelenchus grosmannae is transferred to the new genus as B. grosmannae n. comb. and A. christinae n. comb. (= T. christinae) is proposed. The taxonomic status of Tylaphelenchus is discussed and T. sinodendroni n. comb. (= A. sinodendroni) proposed.

Description of Aphelenchoides giblindavisi n. sp. (Nematoda: Aphelenchoididae), and Proposal for a New Combination

“…Several aspects of the nematode genus Aphelenchoides are attractive for biologists, zoologists and Pedram et al (2018aPedram et al ( , 2018b.…”

“…A 10-47 µm long PUS range is given for A. heidelbergi in its original description (Zhao et al, 2007) and the given range for this trait for A. xui is 68-132 (Wang et al, 2013). As recently emphasized (Pedram et al, 2018a(Pedram et al, , 2018b, such a wide ranges for PUS length should be used with caution in delimiting of species and separating the close species based solely on this trait should be avoided. Measuring of this trait in fresh females in temporary slides could be an alternative approach, much helpful in correct measuring of this organ.…”

“…In a recent study, the species Laimaphelenchus heidelbergi Zhao et al, 2007 was transferred to the genus Aphelenchoides (Carta et al, 2016). In another study, the species Tylaphelenchus christinae Lieutier and Laumond, 1978 was transferred to the genus Aphelenchoides (Pedram et al, 2018a(Pedram et al, , 2018b and finally, two species A. subtenuis (Cobb, 1926) Steiner and Buhrer, 1932 and A. arachidis Bos, 1977 have been transferred to the genus Robustodorus Andrássy, 2007(Kanzaki et al, 2018. The latter action, in revising the taxonomic placement of those two species, was supported by both traditional and molecular criteria.…”

Basilaphelenchus gorganensis n. sp. (Aphelenchoidea, Tylaphelenchinae) from wood from northern Iran

“…The genus Basilaphelenchus Pedram, Kanzaki, Giblin‐Davis, & Pourjam, was recently added to the superfamily Aphelenchoidea Fuchs, . It currently includes three nominal species, viz .…”

“…It currently includes three nominal species, viz . Basilaphelenchus persicus Pedram et al, (the type species); B. grosmannae (Rühm, ) Pedram et al, and B. brevicaudatus Mirzaei Fouladvand, Pourjam, Kanzaki, Giblin‐Davis, & Pedram, . The genus is mainly characterized by having the apomorphic trait of a well posteriorly located metacorpal valve (at >69% of the metacorpus length from its anterior end).…”