Rancel-Rodríguez Nereida M, Afonso-Carrillo Julio, Tronholm Ana, Sansón Marta
Departamento de Botánica, Ecología y Fisiología Vegetal, Facultad de Ciencias, Sección Biología, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez, 38206 La Laguna, Spain.
Department of Biological and Environmental Sciences, University of Gothenburg, P.O. Box 461, 405 30 Göteborg, Sweden.
Plants (Basel). 2023 Jan 16;12(2):416. doi: 10.3390/plants12020416.
Environmental and human factors are inducing a drastic decline in many marine algae in regions with a high floristic richness as in the Canary Islands. Simultaneously, undescribed algal species continue to be discovered, suggesting a probable loss in diversity, before being properly identified and catalogued. Turf-forming Gelidiales occur in marine littoral communities from tropical to warm temperate regions and are challenging to identify correctly because of their small size and simple morphology. In the present study, we combined morphological and molecular phylogenetics methods to study a turf-forming species of the genus from the Canary Islands (NE Atlantic). Both 1 and L gene analyses revealed a novel species described here, sp. nov. The new species has no single unique morphological feature, but it is different by a distinctive combination of attributes, namely, minute size less than 18 mm in height, ribbon-like erect axes, small polygonal cortical cells, cystocarp circular in outline with placental tissue attached to the floor, spermatangial sori with sterile margins with spermatangia simultaneously formed on both sides of the blade, and tetrasporangia arranged in V-shaped rows. Phylogenies inferred from 1 and concatenated genes (1 + L) suggest a link to only two species endemic to South Africa and Madagascar; nevertheless, the L gene establishes as the earliest divergent lineage of the genus.
环境和人为因素正在导致加那利群岛等植物种类丰富地区的许多海洋藻类急剧减少。与此同时，未描述的藻类物种不断被发现，这表明在它们被正确识别和编目之前，可能已经出现了多样性丧失。形成草皮的石花菜目藻类出现在从热带到暖温带的海洋沿岸群落中，由于其体型小和形态简单，很难正确识别。在本研究中，我们结合形态学和分子系统发育学方法，对来自加那利群岛（东北大西洋）的一种形成草皮的石花菜属物种进行了研究。1基因和L基因分析均揭示了这里描述的一个新物种，即石花菜新种。该新物种没有单一独特的形态特征，而是通过一系列独特的特征组合而有所不同，即高度小于18毫米的微小尺寸、带状直立轴、小的多边形皮层细胞、轮廓圆形且底部附着有胎座组织的囊果、具不育边缘且在叶片两侧同时形成精子囊的精子囊群，以及呈V形排列的四分孢子囊。从1基因和串联基因（1 + L）推断的系统发育表明，它仅与南非和马达加斯加特有的两个石花菜物种有联系；然而，L基因确定该物种是石花菜属中最早分化的谱系。
