背景:TaxusLinn的分类法。由于其持续的表型变异和不稳定的拓扑结构,仍然存在争议,从而对该属的科学保护策略的制定产生不利影响。最近,一种新的生态型,被称为秦岭型,主要分布在秦岭,属于单系群。这里,我们采用了多种方法,包括叶片表型比较(叶片形状和微观结构),DNA条形码鉴定(ITS+trnL-trnF+rbcL),和生态位分析,确定秦岭类型的分类地位。
结果:多重比较显示形态特征(长度,宽度,和长宽比)在秦岭型和其他紫杉树种中。叶片解剖分析表明,只有秦岭型和虎杖型没有中脉下的乳头或表皮中的单宁。红豆杉的系统发育分析表明,秦岭型属于单系类群。此外,秦岭型形成了相对独立的生态位,它主要分布在秦岭山脉周围,Ta-pa山,太行山,位于海拔1500m以下。
结论:四个字符,即叶子曲率,边缘锥度,中脉上的丘疹,和边缘被提出作为区分红豆杉种类的主要指标。庆龄型生态型代表了一个独立的进化谱系,并形成了独特的生态位。因此,我们建议将庆龄型视为一种新物种,并将其命名为秦岭红豆杉Y.F.Wen和X.T.Wu,sp.11月。
BACKGROUND: The taxonomy of
Taxus Linn. remains controversial due to its continuous phenotypic variation and unstable topology, thus adversely affecting the formulation of scientific conservation strategies for this genus. Recently, a new ecotype, known as Qinling type, is mainly distributed in the Qinling Mountains and belongs to a monophyletic group. Here, we employed multiple methods including leaf phenotype comparison (leaf shapes and microstructure), DNA barcoding identification (ITS + trnL-trnF + rbcL), and niche analysis to ascertain the taxonomic status of the Qinling type.
RESULTS: Multiple comparisons revealed significant differences in the morphological characters (length, width, and length/width ratio) among the Qinling type and other
Taxus species. Leaf anatomical analysis indicated that only the Qinling type and T. cuspidata had no papilla under the midvein or tannins in the epicuticle. Phylogenetic analysis of
Taxus indicated that the Qinling type belonged to a monophyletic group. Moreover, the Qinling type had formed a relatively independent niche, it was mainly distributed around the Qinling Mountains, Ta-pa Mountains, and Taihang Mountains, situated at an elevation below 1500 m.
CONCLUSIONS: Four characters, namely leaf curvature, margin taper, papillation on midvein, and edges were put forward as primary indexes for distinguishing
Taxus species. The ecotype Qingling type represented an independent evolutionary lineage and formed a unique ecological niche. Therefore, we suggested that the Qingling type should be treated as a novel species and named it
Taxus qinlingensis Y. F. Wen & X. T. Wu, sp. nov.