Abstract Rubus humulifolius is a Eurasian species that has got wide geographic distribution from western parts of Russia to Manchuria. The westernmost and separate population of R. humulifolius was found in Central Finland in 1917. The population was assumed to be formed via anthropogenic dispersal either in early nineteenth or early eighteenth century. In 20's the population was regarded as viable as it covered an area of a hectare almost as a monoculture in the field layer and it was protected by law in 1933. However, the state of the population started to decline in the same year as the area was ditched. In 1957 there were only fifteen rosettes left and five rosettes of were transplanted from the site to a private cottage garden just before the whole area was turned into a construction area and remaining population destroyed. The rescued population thrived but attempts to reintroduce plants from it to other sites considered to be suitable for the species were unsuccessful. Therefore, a research project initiated in 1986 for finding a suitable in vitro method for vegetative propagation of the plant. Eventually, the right formula for a substrate was found and 1500 new plants were produced in a couple of months. Now the in vitro propagated descendants of the five rescued ramets grow in several Finnish botanic gardens as part of their living collections and they also have been reintroduced to a natural site close to the original one in Central Finland. One can assume that a plant population that has gone through two bottlenecks – i.e. establishment of new population by presumably few long-distance dispersed genetic individuals and population decline to near extirpation – has got very narrow genetic diversity. Whether this is the case and whether inbreeding depression could explain e.g. the observed poor seed production in the population remains as a challenge for future research. Owing to ex situ conservation and in vitro technique applied for the first time to reintroduce an endangered species R. humulifolius is no more in immediate danger of extirpation. However, it is still classified as Critically Endangered (CR) as there is still only one population in the wild and it may be genetically depauperate.

中文翻译：

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Rubus humulifolius 以尽可能窄的边缘拯救，移地保存，并重新引入野外

摘要 红叶悬钩子是欧亚种，地理分布广泛，从俄罗斯西部到满洲。R. humulifolius 最西端的独立种群于 1917 年在芬兰中部被发现。该种群被认为是在 19 世纪早期或 18 世纪早期通过人为传播形成的。在 20 年代，人口被认为是可行的，因为它覆盖了几乎作为田间单一栽培的一公顷面积，并于 1933 年受到法律保护。 然而，人口状况在该地区的同一年开始下降被抛弃了。1957年只剩下15个玫瑰花结，5个玫瑰花结就在整个地区变成建筑区和剩余人口被摧毁之前从现场移植到私人平房花园。获救的种群蓬勃发展，但试图将植物从那里重新引入其他被认为适合该物种的地点的尝试没有成功。因此，1986 年启动了一个研究项目，以寻找适合植物营养繁殖的体外方法。最终，找到了合适的基质配方，并在几个月内生产了 1500 株新植物。现在，这五个获救分株的体外繁殖后代生长在芬兰的几个植物园中，作为它们现存的收藏品的一部分，它们也被重新引入芬兰中部靠近原始分株的自然地点。可以假设植物种群经历了两个瓶颈——即 据推测，由少数远距离分散的遗传个体建立新的种群，种群数量下降到接近灭绝——遗传多样性非常有限。情况是否如此以及近交衰退是否可以解释例如观察到的种群中种子产量低下仍然是未来研究的挑战。由于首次采用异地保护和体外技术重新引入濒危物种 R. humulifolius 不再面临灭绝的直接危险。然而，它仍然被归类为极度濒危 (CR)，因为在野外仍然只有一个种群，并且它可能在基因上已经枯竭。观察到的人口中种子产量低下仍然是未来研究的挑战。由于首次采用异地保护和体外技术重新引入濒危物种 R. humulifolius 不再面临灭绝的直接危险。然而，它仍然被归类为极度濒危 (CR)，因为在野外仍然只有一个种群，并且它可能在基因上已经枯竭。观察到的人口中种子产量低下仍然是未来研究的挑战。由于首次采用异地保护和体外技术重新引入濒危物种 R. humulifolius 不再面临灭绝的直接危险。然而，它仍然被归类为极度濒危 (CR)，因为在野外仍然只有一个种群，并且它可能在基因上已经枯竭。