Resumen

GARCIA CASTILLO, María José; RODRIGUEZ ZAPATA, Luis Carlos  y  SANCHEZ TEYER, Lorenzo Felipe. Genomic conservation of two species of the order Asparagales with bimodal karyotype, using genomic in situ hybridization (GISH). Polibotánica [online]. 2025, n.60, pp.367-379.  Epub 10-Nov-2025. ISSN 1405-2768.  https://doi.org/10.18387/polibotanica.60.22.

The Asparagales order, one of the main subdivisions of the monocots, comprises 14 families and more than 36,000 species, notable for its high rate of diversification. Within this order, a wide variability in genome size and karyotype is observed, with some genera showing a bimodal karyotype. The genus Aloe, belonging to the family Asphodelaceae, is notable for its diversity and although most are diploid, tetraploid and hexaploid species have also been identified. Despite this variability in chromosome number, Aloe's bimodal karyotype remains relatively stable, with differences in DNA content between species. In contrast, the Agave genus of the Asparagaceae family, presents a conserved bimodal karyotype with 30 chromosomes in the haploid genome, which includes 5 large chromosomes and 25 small chromosomes. Agave species show natural variations in ploidy, but the basic karyotype pattern is preserved. Phylogeny based on whole genomes suggests that Agave is closely related to other genera such as Manfreda and Polianthes. Research on in situ hybridization and the GISH technique has made it possible to identify and analyze genomic rearrangements and karyotype components in various species. In this context, a study has been carried out to hybridize the genome of Aloe vera in interphase nuclei and metaphase cells of hybrid Agave H11648 to evaluate how an evolutionarily distanced genus integrates into the Agave genome, seeking to better understand the karyotype dynamics in these plants. Our results showed preservation of genomic regions of Aloe in Agave by observing genomic hybridization in all chromosomes and in interface nuclei in hybrid Agave H11648. These data strongly suggest that the bimodal karyotype of agaves was not acquired by the fusion of genomes with different chromosome sizes, but rather by rearrangements, fusions, and fissions during the period of evolution of the genus.

Palabras llave : Agave; Aloe; GISH; Bimodal Karyotype.

        · resumen en Español     · texto en Español     · Español ( pdf )