Olajide Emmanuel, Singh Phougeishangbam Rolish, Kolombia Yao A, Rumbarar Merlin Kornelia, Couvreur Marjolein, Bert Wim
Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
International Institute of Tropical Agriculture (IITA), Head Quarters and West Africa Hub, P.M.B. 5320, Oyo Road, Ibadan 200001, Oyo State, Nigeria.
J Nematol. 2023 May 23;55(1):20230019. doi: 10.2478/jofnem-2023-0019. eCollection 2023 Feb.
The morphological and molecular characterisations of two lance nematode species isolated from the rhizosphere of banana, and , are provided based on an integrative study that includes light and scanning electron microscopy, phylogenetic analysis and two tree-based molecular species delimitation methods (GMYC and bPTP). Nineteen new sequences were obtained, including 5 partial 18S rRNA, 6 D2-D3 of 28S rRNA, 1 ITS rRNA and 7 mtDNA (the first sequences of and ), and an updated morphological character comparison of 37 species is presented. The tree-based molecular species-delimitation approaches employed gave markedly differing results, and also showed remarkable discrepancies among the investigated genes, although the bPTP output was found to agree well with established morphological species delimitations. Both species-delimitation approaches did, however, provide the same output for the mtDNA sequences, and the mtDNA gene sequence was also found to correspond better to established morphological species. It is therefore recommended by this paper as representing the most suitable barcode marker for species identification. This integrative study also resulted in the corrective reassignment of 17 gene sequences that were previously unidentified or incorrectly classified, as well as concluding that consists of two cryptic species.
基于一项综合研究，提供了从香蕉根际分离出的两种长矛线虫（Lance nematode）物种——[物种名称1]和[物种名称2]的形态学和分子特征。该综合研究包括光学显微镜和扫描电子显微镜观察、系统发育分析以及两种基于树的分子物种界定方法（GMYC和bPTP）。获得了19个新序列，包括5个部分18S rRNA、6个28S rRNA的D2-D3、1个ITS rRNA和7个线粒体DNA（[物种名称1]和[物种名称2]的首个线粒体DNA序列），并给出了37个长矛线虫物种的更新形态特征比较。尽管发现bPTP的结果与已确立的形态学物种界定高度吻合，但所采用的基于树的分子物种界定方法得出了明显不同的结果，并且在所研究的基因之间也显示出显著差异。然而，两种物种界定方法对线粒体DNA序列给出了相同的结果，并且还发现线粒体DNA基因序列与已确立的形态学物种对应得更好。因此，本文推荐该线粒体DNA基因序列作为[物种名称1]和[物种名称2]物种鉴定的最合适条形码标记。这项综合研究还导致对17个先前未鉴定或分类错误的基因序列进行了校正重新分配，并得出结论认为[物种名称1]由两个隐存物种组成。
