Longidorus pisi Edward, Misra & Singh, 1964

Lazarova, Stela S., Elshishka, Milka, Radoslavov, Georgi, Lozanova, Lydmila, Hristov, Peter, Mladenov, Alexander, Zheng, Jingwu, Fanelli, Elena, Francesca De Luca, & Peneva, Vlada K., 2019, Molecular and morphological characterisation of Longidoruspolyae sp. n. and L. pisi Edward, Misra & Singh, 1964 (Dorylaimida, Longidoridae) from Bulgaria, ZooKeys 830, pp. 75-98 : 82-84

Longidorus pisi Edward, Misra & Singh, 1964

= Longidorus latocephalus Lamberti, Choleva & Agostinelli, 1983

Notes.

Morphological and morphometric data for females and juvenile stages are presented in Table 4 and in Figure 8. The morphometric data obtained in this study agreed with those of L. latocephalus from its type locality ( Lamberti et al. 1983) and several additional populations studied by Lamberti et al. (1997). Furthermore, when compared to the type population of L. pisi ( Edward et al. 1964), specimens from our populations revealed longer odontostyle (average 75 (72-79) and average 76 (74-78) vs 58 (56-61) μm) and odontophore (average 50 (45-53) and average 49 (46-53) vs average 42.7 (35-43) μm); longer distances anterior end to guide (average 44 (42-46) vs average 32 (31-35) μm) and nerve ring (average 147 (138-151) and 141 (132-150) vs average 133 μm); wider (average 10.6 vs 7.5 μm) and higher (5-6 vs 3.5 μm) lip region and lower c’ ratio (average 1.9 (1.5-2.0) and average 1.7 (1.5-1.8) vs average 2.5 (2.4-2.6). The morphometrics of our populations were more similar to the Iranian population of L. pisi (Saveh, Markazi province) for which a D2-D3 expansion domain of 28S rRNA gene sequence identical to ours is available ( Pedram et al. 2012). Differences in a few characters were observed, e.g. smaller a (average 125.2 (117.2-132.1) and 127.3 (119.8-132.9) vs 139.4 (134.8-144.6) and c’ (average 1.9 (1.5-2.0) and average 1.7 (1.5-1.8) vs average 2.5 (2.3-2.9) values, larger diameter at anus level (average 22.9 (21-24.5) and average 20.5 (20-22) vs average 18.1 (16-19) μm) and slightly shorter tail (average 38.9 (36-43) and average 39.1 (37-42) vs average 45 (43-47) μm) compared to the latter population.

Sequence and phylogenetic analyses.

Three ribosomal DNA regions (D2-D3 expansion segments of 28S rRNA gene, 18S rRNA gene, and ITS1-5.8S-ITS2 regions) of L. pisi were amplified and sequenced. The D2-D3 expansion segments of 28S rRNA gene sequences from all populations were identical to that of the Iranian population (JQ240274, Pedram et al. 2012) and differed slightly (1 and 3 bp) from those of other populations (Greece (AY601569) and South Africa (AY601568), respectively) identified as L. latocephalus ( He et al. 2005). In the phylogenetic analysis, all aforementioned sequences formed a clade with maximal Bayesian posterior probability (1.0) and showed a close relationship with L. mindanaoensis . The BLASTn search using 18S rRNA gene sequence revealed highest identity (99%) with five accessions (two Longidorus (HQ735099 L. mindanaoensis Coomans, Tandingan De Ley, Angsinco Jimenez & De Ley, 2012 and AY283163 L. ferrisi Robbins, Ye & Pedram, 2009) and three Paralongidorus species (JN032586 P. bikanerensis (Lal & Mathur, 1987) Siddiqi, Baujard & Mounport, 1993; AJ875152 P. maximus ( Bütschli, 1874) Siddiqi, 1964 and KJ427794 P. rex Andrássy, 1986). A pairwise comparison of L. pisi sequence with the closest sequences (AY283163, HQ735099, JN032586, AJ875152 and KJ427794) revealed 14-22 different nucleotides. The 18S rDNA phylogenetic tree is presented in Figure 10.