Abstract

The degree of intraspecific genetic polymorphism and heterozygosity, the germinal death, viability of seeds, and the cytogenetic state of vegetative Ulmus pumila and U. suberosa meristems were analyzed for determining the mechanisms of plant population invasiveness in the steppe Dnieper region under climate changes. The studied U. pumila population were different in terms of germinal (embryonic) death, seed viability and seed productivity. Populations grown under more favorable environmental conditions had the best reproductive, physiological and genetic conditions. For the majority of used microsatellite loci, population studies were characterized by a relatively low level of genetic variability, an excess of homozygous genotypes and a deficiency of heterozygotes, which indicated a certain level of inbreeding of the analyzed plants. The highest deficiency of heterozygotes was found in U. pumila populations with high stand density and significant indices of germinal seed loss; smaller deficits were in populations with a larger area and low stand density and, accordingly, low rates of germinal death. The low index of chromosomal rearrangements in the vegetative meristems also confirmed an insignificant level of genetic variability and the probable absence of hybridization and genetic homeostasis in U. pumila. The U. suberosa population was characterized by increased indices of germinal death, seed damage and low seed productivity, which correlated with an excess of homozygous genotypes. All U. suberosa specimens were monomorphic by the microsatellite loci. In general, by genetic and reproductive indices, seed reproduction and distribution of U. pumila in the steppe Dnieper region is not significantly limited under climate change. At the same time, seed reproduction of U. suberosa may be limited.

中文翻译：

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气候变化对第聂伯草原榆树和U. suberosa入侵种群的遗传和生殖状态评估

摘要

通过分析种内遗传多态性和杂合度，种子的生死，种子的活力以及营养性榆树和U. suberosa分生组织的细胞遗传状态，来确定气候变化条件下草原第聂伯地区植物种群入侵的机制。研究过的U. pumila种群的生发（胚）死亡，种子活力和种子生产力不同。在更有利的环境条件下生长的种群具有最佳的繁殖，生理和遗传条件。对于大多数使用的微卫星基因座，种群研究的特点是相对较低的遗传变异性，纯合的基因型过多和杂合子的缺乏，这表明所分析植物的近交程度较高。在U. pumila中发现杂合子的最高缺乏症林分密度高，生种子损失指数高的种群；在较大面积和低林分密度的人群中赤字较小，因此生发死亡率较低。营养分生组织的染色体重排指数较低，也证实了U. pumila的遗传变异水平不高，可能没有杂交和遗传稳态。的U.木栓状人口特征在于增加的生发死亡，种子损伤和低种子生产率的指标，其与过量的纯合子的基因型的相关性。通过微卫星基因座，所有U. suberosa标本都是单态的。一般而言，通过遗传和生殖指标，种子的繁殖和分布受到气候变化的影响，草原第聂伯地区的U. pumila不受显着限制。同时，Sub。suberosa的种子繁殖可能受到限制。