Systematics, distribution, and sexual compatibility of six Scytosiphon species (Scytosiphonaceae, Phaeophyceae) from Japan and the description of four new species
Systematics, distribution, and sexual compatibility of six Scytosiphon species (Scytosiphonaceae, Phaeophyceae) from Japan and the description of four new species
复制标题
DOI：
10.1111/jpy.13089
复制
发表时间：
2020-12-18
影响因子：
2.9
通讯作者：
Kogame, Kazuhiro
中科院分区：
文献类型：
--
作者：
Hoshino, Masakazu;Tanaka, Atsuko;Kogame, Kazuhiro
据报道，褐藻 Scytosiphon lomentaria（Scytosiphonaceae，Ectocarpales）在世界各地的冷水和暖水中均有发现。尽管之前的分子系统发育研究和杂交实验表明它是多个不同物种的复合体，但每个物种的分类位置和准确分布仍不清楚。对于来自日本的 S. lomentaria 复合体，我们的 cox1 和 rbcL 系统发育分析检测到了 6 个物种。除了先前发现的 5 种（Ia-Va 种）外，在冲绳岛亚热带地区新发现了 1 种（VI 种）。物种 VI 作为物种 Ia-Va 的姐妹在 rbcL 中被发现。根据形态学和系统发育数据，我们得出结论，Ia种为S. lomentaria，IIIa种为S. promiscuus，其他4种是新描述的：S. shibazakiorum为种IIa，S. tosaensis为种IVa，S. arcanus为种Va，S. subtropicus为种VI。基于cox1的分析还表明，S. lomentaria、S. shibazakiorum和S. promiscuus在世界范围内都有分布，而其他三个物种在日本以外的地区没有发现。在日本，除了S. subtropicus外，这些物种的分布是重叠的。我们的杂交实验表明，与同域物种相比，异域物种（即亚热带链球菌和其他物种）之间的配子不相容性（合子前屏障）较不发达。这可能表明，由于强化，同域物种之间已经进化出合子前障碍。
The brown alga Scytosiphon lomentaria (Scytosiphonaceae, Ectocarpales) has been reported from cold and warm waters worldwide. Although previous molecular phylogenetic studies and crossing experiments have shown that it is a complex of multiple distinct species, the taxonomic position and accurate distribution of each species have remained largely unclear. For the S. lomentaria complex from Japan, our cox1 and rbcL phylogenetic analyses detected six species. In addition to five previously detected species (species Ia-Va), one species (species VI) was newly found in the subtropical area, Okinawa Island. Species VI was recovered as a sister to species Ia-Va in rbcL. Based on the morphological and phylogenetic data, we concluded that species Ia is S. lomentaria, species IIIa is S. promiscuus, and the other four species are newly described: S. shibazakiorum for species IIa, S. tosaensis for species IVa, S. arcanus for species Va, and S. subtropicus for species VI. The cox1-based analysis also showed that S. lomentaria, S. shibazakiorum, and S. promiscuus have worldwide distributions, while the other three species were not found outside of Japan. In Japan, except for S. subtropicus, distributions of these species overlapped. Our crossing experiments showed that gametic incompatibility (pre-zygotic barrier) was less developed between the allopatric species (i.e., S. subtropicus and others) compared with the sympatric species. It may suggest that pre-zygotic barriers have evolved among the sympatric species due to reinforcement.