Description of Boleodorus bushehrensis n. sp. (Rhabditida: Tylenchidae) from Southern Iran, and Observations on a Commonly Known Species

Abstract

A new species of the genus Boleodorus, recovered from southern Iran, is described and illustrated based upon morphological and molecular data. B. bushehrensis n. sp. is mainly characterized by having a wide and low cephalic region (which is continuous with the adjacent body), the oral aperture in a depression in side view under a light microscope, four lines in the lateral field, weak metacorpus with a vestigial-to-invisible valve, and short (26–38 mm long) hooked tail with rounded tip. The females are 334–464 mm long and have a spherical spermatheca filled with spheroid sperm; males have 11.5- to 12.0-mm-long spicules and weakly developed bursa. The new species has an annulated low cephalic region, four large cephalic papillae, and small crescent-shaped amphidial openings when observed by scanning electron microscopy (SEM). Its morphological and morphometric differences with seven known species are discussed. The phylogenetic relationships of the new species with other relevant genera and species have been studied using partial sequences of small and large subunit ribosomal DNA (SSU and LSU rDNA). In both the SSU and LSU phylogenies, the sequences of B. bushehrensis n. sp. and other Boleodorus spp. formed a clade. A second species, B. thylactus, when studied under SEM, has a raised, smooth cephalic region, four large cephalic papillae, and oblique amphidial slits, with the oral opening in a depression.

Morphological and Molecular Characterization of Filenchus multistriatus n. sp. (Tylenchomorpha: Tylenchidae) and Data on a Known Species of the Genus from Bushehr Province, Southern Iran

“…Furthermore, the interpretation of morphological and morphometric differences as "intraspecies variations" may yield to incorrect assignments of given populations to species. In a study by Monemi et al (2022), it has been shown that several sequences assigned to Boleodorus thylactus Thorne, 1941 have occupied different placements in corresponding trees, and as the conclusion, the original descriptions of the Tylenchidae species or data given in redescriptions of the species based on type specimens, are reliable resources in taxonomic studies of this group of nematodes. In accordance with some recent phylogenies using ribosomal markers (e.g.…”

“…The new species has a low flat lip region, which has already been reported for some other Tylenchidae spp. (Geraert, 2009; Monemi et al., 2022 ).…”

Morphological and Molecular Characterization of Ottolenchus isfahanicus n. sp. (Tylenchomorpha: Tylenchoidea) from Rhizosphere of Gramineous Plants in Isfahan Province, Iran

“…The morphometrics of most species of Tylenchidae have been expanded following numerous reports ( Geraert, 2008 ); however, most of the original and subsequent reports lack molecular sequences, making the identification of most of the species questionable. Monemi et al (2022) stated that most of the sequences assigned to Boleodorus thylactus Thorne, 1941 probably belong to cryptic forms, and therefore, topotype sequences of the species are needed to decide on their identity. Likewise, topotype sequences have been used to prove the status of sequences assigned to Xiphinema brevicolle Lordello and Da Costa, 1961 ( Lazarova et al, 2019 ) and X. robbinsi Pedram, Niknam & Decraemer, 2008 ( Jahanshahi Afshar, 2019 ).…”

“…was compared with other available sequences in the GenBank database using the basic local alignment search tool (BLAST). Relevant sequences (mostly belonging to the subfamily Tylenchinae) used in SSU phylogeny in previous studies ( Monemi et al, 2022 ) were selected for inferring the SSU tree. Two sequences of Aphelenchoidea Fuchs, 1937, namely Bursaphelenchus mucronatus Mamiya & Enda, 1979 (AY284648) and Aphelenchoides fragariae Ritzema Bos, 1890 (AY284645), were selected as outgroups.…”

“…were compared with other available sequences in the GenBank database using BLAST homology search program. The maximal number of relevant sequences as already used in our previous studies ( Monemi et al, 2022 ; Mortazavi et al, 2021 ) were included in LSU phylogeny.…”