Abstract—

Clones of two morphotypes corresponding to two species of pennate araphid diatoms, Ulnaria ulna and U. acus, were isolated from samples taken in Europe. Clonal cultures entered heterothallic sexual reproduction in combinations appropriate to their mating types. Following the concept of biological species, we tested reproductive compatibility between all representatives of geographically distant populations. Isolated clones proved to be reproductively compatible within the limits of each of the species; the progeny (generation F1) were viable and fertile and freely entered into backcrossing. No cases of interspecies hybridization were found. The absence of intraspecific reproductive isolation between distant populations in these two species suggests that the populations of both U. ulna and U. acus are conspecific.

中文翻译：

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两种尺蠖属（Bacillariophyta）的欧洲种群的繁殖相容性

摘要-

从欧洲采集的样本中分离出对应于两种羽状蚜虫硅藻Ulnaria ulna和U. acus的两种形态型的克隆。克隆培养物以适合其交配类型的组合进入异种有性生殖。遵循生物物种的概念，我们测试了地理上遥远种群的所有代表之间的生殖兼容性。孤立的克隆被证明在每个物种的范围内都具有繁殖兼容性；后代（F1 代）是有活力和可育的，并且可以自由地进行回交。没有发现种间杂交的情况。这两个物种的远距离种群之间不存在种内生殖隔离，这表明两者的种群U. ulna和U. acus是同种的。