Agricultural Institute of Slovenia, Plant Protection Department, 1001 Ljubljana, Slovenia.
Plant Dis. 2017 Sep;101(9):1627-1632. doi: 10.1094/PDIS-02-17-0220-RE. Epub 2017 Jun 27.
The tropical group of root-knot nematodes (RKN) including Meloidogyne ethiopica and M. luci is a highly polyphagus and damaging group of agricultural pests. M. ethiopica has been detected in several European countries (Slovenia, Italy, Greece) and also in Turkey. However, a description of a new sister species M. luci calls for reclassification of all European and Turkish M. ethiopica populations reported up to date as M. luci. Accurate identification can be accomplished through analysis of the esterase isozyme pattern, which is the most distinguishing character between the two otherwise very similar species. Both species display a three banded esterase pattern where the upper band is slightly shifted between the two species. In addition, molecular characterization of M. ethiopica and M. luci populations revealed that the ITS, SSU, and LSU of the rDNA regions are not appropriate markers for studying relationships among the tropical group of RKNs. However, the COII/lRNA region on mtDNA proved to be very useful for analyzing the phylogenetic relationship of these very closely related species/populations. Mitochondrial sequences with low levels of heteroplasmy allowed clustering of all M. luci populations in a monophyletic clade with a clear separation of this recently described species from M. ethiopica. At the same time, a very close relationship between M. ethiopica and M. luci was confirmed again.
热带根结线虫群(RKN)包括埃塞俄比亚根结线虫和 M. luci,是一组高度杂食性和极具破坏性的农业害虫。埃塞俄比亚根结线虫已在几个欧洲国家(斯洛文尼亚、意大利、希腊)和土耳其被发现。然而,一个新的姐妹种 M. luci 的描述要求对迄今为止报告的所有欧洲和土耳其的埃塞俄比亚根结线虫种群进行重新分类,将其归类为 M. luci。通过酯酶同工酶模式的分析可以准确识别,这是这两个非常相似的物种之间最具区别的特征。这两个物种都显示出三带酯酶模式,其中上带在两个物种之间略有偏移。此外,对埃塞俄比亚根结线虫和 M. luci 种群的分子特征分析表明,ITS、SSU 和 LSU 的 rDNA 区域不是研究热带根结线虫群之间关系的合适标记。然而,mtDNA 上的 COII/lRNA 区域被证明对于分析这些非常密切相关的物种/种群的系统发育关系非常有用。线粒体序列具有低水平的异质性,允许将所有 M. luci 种群聚类在一个单系群中,明确区分这个最近描述的物种与埃塞俄比亚根结线虫。同时,再次证实了埃塞俄比亚根结线虫和 M. luci 之间非常密切的关系。