گزارش دو گونه نماتد متعلق به جنس Ditylenchus برای فون نماتدهای ایران

In order to identify some nematodes in northern forests of Iran, several soil and tree bark samples were collected from northern forests of Iran, during periodic sampling from 2015 to 2017. After recording the information of samples, the samples were transferred to laboratory. Nematodes were extracted using tray method, killed and fixed following De Grisse’s (1969) method. Temporary and permanent microscopic slides of nematodes were prepared and studied using morphological and morphometric characters. Molecular studies using partial 18S rDNA and 28S rDNA D2/D3 sequences by both the Bayesian and maximum likelihood analyses were done. Two species of Ditylenchus were reported in this study. D. acuminatus, recovered from forests of Gilan province, characterized by short body, four lines on lateral field, short stylet with weak knobs, median pharyngeal bulb having central valve, basal pharyngeal bulb with short dorsal overlap on intestine, position of vulva at 81.8-84.9, long post uterine sac (PUS) about 0.8-1.3 times of body width at vulva and long conical tail, 36-49 µm with rounded to pointed tip. In this study, male population of this species was not found. In comparison between Iran population with original population by Khan and Nanjappa (1972) no significant difference was observed. D. bhatnagari, other species reported in this study, was recovered from forests of Golestan province. This species having short body, four lines on lateral field, short stylet with tiny knobs, median pharyngeal bulb without central valve, basal pharyngeal bulb offset from intestine, position of vulva at 81.7-85.2, short PUS about 0.5-0.7 times of body width at vulva and conical tail, 36-53 µm long with rounded to pointed tip. Male population of this species was not found. Comparison between Iranian population with original description of D. bhatnagari Tikyani & Khera, 1969 showed that b index (3.6-5.0 vs 5.0-6.6) was different. Phylogenetic analyses using 18S rDNA and 28S rDNA D2/D3 sequences showed that both abovementioned species were belong to D. dipdaci-group.