Alloploidization resulting from remote (interspecific or intergeneric) hybridization is one of the main factors in plant evolution, leading to the formation of new species. Triticale (× Triticosecale Wittmack, 1889) is the first artificial species created by crossing wheat (Triticum spp.) and rye (Secale cereale Linnaeus, 1753) and has a great potential as a grain and forage crop. Remote hybridization is a stress factor that causes a rapid reorganization of the parental genomes in hybrid progeny ("genomic shock") and is accompanied by abnormalities in the chromosome set of hybrids. The formation of the hybrid genome and its subsequent stabilization are directly related to the normalization of meiosis and the correct chromosome segregation. The aim of this work was to cytogenetically characterize triticale (× Triticosecale rimpaui Wittmack, 1899, AABBDDRR) obtained by crossing Triticum aestivum Linnaeus, 1753. Triple Dirk D × Secale cereale L. Korotkostebel'naya 69 in F3-F6 generations of hybrids, and to trace the process of genetic stabilization of hybrid genomes. Also, a comparative analysis of the nucleotide sequences of the centromeric histone CENH3 genes was performed in wheat-rye allopolyploids of various ploidy as well as their parental forms. In the hybrid genomes of octoploid triticale an increased expression of the rye CENH3 variants was detected. The octoploid triticale plants contain complete chromosome sets of the parental subgenomes maintaining the chromosome balance and meiotic stability. For three generations the percentage of aneuploids in the progeny of such plants has been gradually decreasing, and they maintain a complete set of the paternal rye chromosomes. However, the emergence of hexaploid and new aneuploid plants in F5 and F6 generations indicates that stabilization of the hybrid genome is not complete yet. This conclusion was confirmed by the analysis of morphological features in hybrid plants: the progeny of one plant having the whole chromosome sets of parental subgenomes showed significant morphological variations in awn length and spike density. Thus, we expect that the results of our karyotyping of octoploid triticales obtained by crossing hexaploid wheat to diploid rye supplemented by comparative analysis of CENH3 sequences will be applicable to targeted breeding of stable octo- and hexaploid hybrids.

中文翻译：

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八倍体小黑麦（×Triticosecale Wittmack）中黑麦基因组的细胞遗传学和分子特征。

远程（种间或属间）杂交产生的异源化是植物进化的主要因素之一，从而导致新物种的形成。黑小麦（×Triticosecale Wittmack，1889年）是由小麦（Triticum spp。）和黑麦（Secale graine Linnaeus，1753年）杂交产生的第一个人工物种，具有作为谷物和饲料作物的巨大潜力。远程杂交是引起杂种后代中亲本基因组快速重组的应激因素（“基因组休克”），并伴随杂种的染色体组异常。杂交基因组的形成及其随后的稳定与减数分裂的正常化和正确的染色体分离直接相关。这项工作的目的是通过杂交小麦（Triticum aestivum Linnaeus）（1753年）获得小黑麦（×Triticosecale rimpaui Wittmack，1899，AABBDDRR）的细胞遗传学特征。追踪杂交基因组的遗传稳定过程。同样，在各种倍性及其亲本形式的小麦-黑麦同素多倍体中进行着丝粒组蛋白CENH3基因核苷酸序列的比较分析。在八倍体黑小麦的杂种基因组中，检测到黑麦CENH3变体的表达增加。八倍体小黑麦植物含有完整的亲本亚基因组染色体集，可保持染色体平衡和减数分裂稳定性。在三代中，此类植物后代中非整倍体的百分比逐渐降低，并且它们维持了完整的父本黑麦染色体。但是，六倍体和新的非整倍体植物在F5和F6代中的出现表明杂种基因组的稳定作用尚未完成。通过对杂交植物的形态学特征的分析证实了这一结论：具有亲本亚基因组的整个染色体组的一种植物的后代在芒长和穗密度上显示出明显的形态变化。因此，我们希望通过将六倍体小麦杂交为二倍体黑麦而获得的八倍体黑小麦的染色体核型分析结果，并通过CENH3序列的比较分析加以补充，将可用于稳定的八倍体和六倍体杂种的定向育种。