Abstract

The article summarizes and systematizes the results of studies by Russian and foreign authors related to the population-genetic features of the main members (silver birch Betula pendula L., downy birch Betula pubescens Ehrh., curly (or Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti) of the birch genus (Betula L.) growing in the forest zone of Europe. Information is provided about the formation of birch populations in the region and about its migration pathways when recolonizing the territory after the Ice Age. We demonstrate that due to certain geographic and climatic affiliations there appeared zones of hybridization between different birch species, which had an effect on the subsequent evolution of this genus. Attention is given to the role of hybridization in shaping the genetic structure of the birch population in the northwestern part of continental Europe, where introgression has generated unusual genotypes and haplotypes, among which curly birch has probably become differentiated. We argue that the introgressive hybridization of species observed now and then in the birch genus may be of the main reasons for the problems with definite taxonomic identification of silver birch and downy birch. It is also remarked that curly birch, although meeting the conventional biological criteria of a species, is still regarded a variety of silver birch. Having analyzed the population-genetic features of members of the genus Betula L., the authors conclude that the species status of silver birch and downy birch should be retained in spite of the identification difficulties and that instating curly birch as a separate biological species is advisable. We emphasize the importance and relevance of studying the population-genetic features of both common and rare members of the Betula genus to enable the development of efficient methods and practices of their selective breeding and reproduction of the most valuable genotypes as a solid scientific foundation for sustainable forest management.

中文翻译：

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桦木属：物种特异性种群遗传特征和分类问题

摘要

本文总结并系统化了俄罗斯和外国作者有关主要成员（银桦Betula pendula L.、绒毛桦Betula pubescens Ehrh.、卷曲（或卡累利阿）桦Betula pendula Roth var）种群遗传特征的研究结果。 .carelica (Mercklin) Hämet-Ahti) 属于桦树属 ( Betula L.)，生长于欧洲森林地带。提供了有关该地区白桦种群形成及其冰河时代后重新殖民该地区时的迁徙途径的信息。我们证明，由于某些地理和气候关系，不同桦树物种之间出现了杂交区域，这对该属的后续进化产生了影响。人们关注杂交在塑造欧洲大陆西北部桦树种群遗传结构中的作用，那里的基因渗入产生了不寻常的基因型和单倍型，其中卷曲桦树可能已经分化。我们认为，在桦属中时不时观察到的物种渐渗杂交可能是银桦和绒桦明确分类学鉴定问题的主要原因。还指出，卷曲桦树虽然符合物种的常规生物学标准，但仍被视为银桦树的变种。分析了桦属成员的群体遗传特征。，作者的结论是，尽管存在鉴定困难，但应保留银桦和绒桦的物种地位，并且建议将卷曲桦列为单独的生物物种。我们强调研究桦属常见和稀有成员的群体遗传特征的重要性和相关性，以开发有效的方法和实践，选择性育种和繁殖最有价值的基因型，为可持续发展奠定坚实的科学基础。森林管理。