Molecular and morphological characterization of the seed gall nematodes Anguina tritici from central and southern Iraq

This is the first morphological investigation of the wheat gall nematodes Anguina tritici found on wheat in southern and midland areas of Iraq. A survey was conducted, and samples were collected from wheat fields in eight governorates (Diyala, Baghdad, Qadisiyah, Najaf, Wasit, Maysan, Dhi Qar and Basra, 3 regions each and three fields for each region during the 2020-2021 growing season. Wheat-gall nematodes were extracted and observed under a stereomicroscope. Nematodes of interest were hand-picked, identified and photo-micro-graphed using a microscope equipped with a digital camera. Two species of anguinid nematodes (Anguinidae: Tylenchida) were found and characterized. This species is characterized by its 810-905 mm long body, body slightly curved to almost straight, with a 9-10 μm small stylet with delicate lip region very slightly offset, pharyngeal lobe long, wider than adjacent body part and 16-17µm broad, distance of dorsal gland orifice to the style 2-4, position of dorsal gland orifice to the style base expressed as a percentage of the total style length20-40 µm. Anterior end to the valve of the median bulb 67 -72µm; anterior end to excretory. Tail long, gradually tapering to an acute tip without mucro 61 -70 µm. As for the molecular identification and comparison with the GenBank, sequencing of Dhi Qar samples showed having three transitions at sites 59,125,168 G\T, G\T, and G\A, respectively, and one transversion at 140 G\C site. It was found that the ITS gene has a compatibility of 98% with the original sequence conserved in the Genbank with ID KC818619. As for the Anguina tritici isolated from Basra, it contains two transitions at locations 247 and 253 C\T, four transversions 238,245,249, 251 G\T, G\C, A\C, and T\A, respectively, with similarity of 97%. Maysan samples were compatible with 98% and had one transition at 168 G\A site and three transversions at the locations 125,128.25 G\T. ITS gene from Diyala showed 98% compatibility with the sequence in GenBank, having one transition at locus G\A 93 and three transversions at 83,78,59 G\T, G\C, and G\T, respectively. Two transversions in locations 59,117 nucleotide G\T, A\C in Al-Kut samples, and at 125,142 G\T, G\C in Baghdad ones, while Najaf samples had one transversion, and one transition in sites 213, 234 G\C, C\T respectively, as all of them showed 99% similarity with the original sequence in GenBank. Bionatura http://dx.doi.org/10.21931/RB/CSS/2023.08.97 2 Keywords: Field crop, PCR, PPN, wheat