Papanin Institute for Biology of Inland Waters RAS, Borok, Nekouz District, Yaroslavl Region, 152742, Russia.
Tyumen State University, AquaBioSafe, Lenina Str., 25, Tyumen, 625003, Russia.
Sci Rep. 2022 Jul 15;12(1):12088. doi: 10.1038/s41598-022-16224-0.
We demonstrate a wide distribution and abundance of hybrids between the river species Ranunculus aquatilis, R. fluitans and R. kauffmannii with the still water species R. circinatus (Batrachium, Ranunculaceae) in rivers of two postglacial landscapes of East Europe, i.e., Lithuania and Central European Russia. The Batrachium species and hybrid diversity is higher in the rivers of Lithuania (4 species and 3 hybrids vs. 2 and 1) and represented mainly by western R. aquatilis, R. fluitans and their hybrids whereas in Central European Russia, the East European species R. kauffmannii and its hybrid are the only dominant forms. Hybrids make up about 3/4 of the studied individuals found in 3/4 of the studied river localities in Lithuania and 1/3 of the individuals found in 1/3 of the localities in Central European Russia. Such extensive hybridization in river Batrachium may have arisen due to the specificity of rivers as open-type ecosystems. It may have been intensified by the transformation of river ecosystems by human activities and the postglacial character of the studied landscapes combined with ongoing climate change. Almost all hybrids of R. aquatilis, R. fluitans and R. kauffmannii originated from unidirectional crossings in which R. circinatus acted as a pollen donor. Such crossings could be driven by higher frequency and abundance of R. circinatus populations as well as by some biological mechanisms. Two hybrids, R. circinatus × R. fluitans and R. circinatus × R. kauffmannii, were formally described as R. × redundans and R. × absconditus. We found a hybrid which most likely originated from additional crossing between R. aquatilis and R. circinatus × R. fluitans.
我们展示了在东欧两个后冰川景观的河流中，即立陶宛和中欧俄罗斯，水生植物 Ranunculus aquatilis、R. fluitans 和 R. kauffmannii 与静水物种 R. circinatus（Batrachium，毛茛科）之间广泛分布和丰富的杂交种。立陶宛河流中的 Batrachium 物种和杂交种多样性更高（4 个物种和 3 个杂交种与 2 个和 1 个），主要由西部的 R. aquatilis、R. fluitans 及其杂交种组成，而在中欧俄罗斯，东欧物种 R. kauffmannii 及其杂交种是唯一的主要形式。在立陶宛的 3/4 的研究地点和中欧俄罗斯的 1/3 的研究地点发现的个体中，杂交种约占 3/4。河流中的这种广泛杂交可能是由于河流作为开放型生态系统的特殊性而产生的。它可能因人类活动对河流生态系统的改造以及所研究景观的后冰川特征以及正在发生的气候变化而加剧。R. aquatilis、R. fluitans 和 R. kauffmannii 的几乎所有杂交种都源自单向杂交，其中 R. circinatus 充当花粉供体。这种杂交可能是由 R. circinatus 种群的更高频率和丰度以及某些生物学机制驱动的。两个杂交种，R. circinatus × R. fluitans 和 R. circinatus × R. kauffmannii，被正式描述为 R. × redundans 和 R. × absconditus。我们发现了一个可能源自 R. aquatilis 和 R. circinatus × R. fluitans 之间额外杂交的杂交种。
