During several nematological surveys in cultivated and natural habitats in Khuzestan and Zanjan provinces of Iran, a new species, Bitylenchus parvulus n. sp., two new records for Iran – namely, Tylenchorhynchus agri and Tylenchorhynchus graciliformis – and a population of Bitylenchus parvus and one of Sauertylenchus maximus were recovered and characterized based upon morphological and molecular approaches. The new species is characterized by lip region with five to seven annuli, stylet 17.7 (17.0–18.5) μm long, sub-cylindrical tail narrowing abruptly near terminus giving a bluntly digitate shape to the tail tip, cuticle near anterior part of vulva wrinkled and post-rectal sac occupies whole of tail cavity. The phylogenetic analyses were carried out using molecular data from D2–D3 expansion segments of large ribosomal subunit (28S rRNA) for all studied species and the partial small ribosomal subunit (18S rRNA) for the new species. The representatives of Bitylenchus and Sauertylenchus formed distinct clades from Tylenchorhynchus members, supporting the hypothesis in which Bitylenchus and Sauertylenchus could be considered as valid genera, but rejecting the ‘large-genus’ concept for Tylenchorhynchus. Also, Sauertylenchus ibericus was proposed as a junior synonym of S. maximus based on the results from morphological and phylogenetic analysis. Furthermore, an identification key for all known species included in the three genera Bitylenchus, Tylenchorhynchus and Sauertylenchus is presented herein. The number of transverse annuli on the lip region and presence/absence of post-rectal sac were considered as the main diagnostic characters for classifying the species into seven groups, and other morphological and morphometric characters were subsequently used for distinguishing species in each group.

中文翻译：

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密切相关属 Bitylenchus、Sauertylenchus 和 Tylenchorhynchus（线虫：Telotylenchinae）的分类学考虑和分子系统发育，其中一个新物种和四个已知物种来自伊朗

在对伊朗胡齐斯坦省和赞詹省的栽培和自然栖息地进行的几次线虫学调查中，一种新物种，小扁豆n. sp.，伊朗的两项新记录——即，虎嘴龙和细长喙嘴龙– 和人口小扁豆和其中之一大长矛基于形态学和分子学方法进行回收和表征。新种的特征是唇区有5-7个环状物，管心针长17.7（17.0-18.5）μm，亚圆柱形尾巴在末端附近突然变窄，使尾尖呈钝指状，外阴前部附近的角质层起皱和直肠后囊占据整个尾腔。系统发育分析使用来自所有研究物种的大核糖体亚基 (28S rRNA) 的 D2-D3 扩增片段和新物种的部分小核糖体亚基 (18S rRNA) 的分子数据进行。的代表比泰伦丘斯和酸杆菌属形成了不同的进化枝虎嘴龙成员，支持假设比泰伦丘斯和酸杆菌属可以被认为是有效的属，但拒绝“大属”的概念虎嘴龙. 还，伊比利亚短吻鳄被提议作为初级同义词S. maximus基于形态学和系统发育分析的结果。此外，三个属中所有已知物种的识别码比泰伦丘斯,虎嘴龙和酸杆菌属在此介绍。唇区横环的数量和有无直肠后囊被认为是将该物种分为七组的主要诊断特征，随后使用其他形态学和形态学特征来区分每组中的物种。