Resumo

IMERY BUIZA, José  e  CEQUEA RUIZ, Hernán. Anormalidades Cromosómicas en la Microsporogénesis de Aloe Vera (L.) Burm. F. (Aloaceae). Acta Bot. Venez. [online]. 2002, vol.25, n.2, pp.143-152. ISSN 0084-5906.

The objective of this work is to verify the existence of chromosomic abnormalities associated to the low fertility of pollen in Aloe vera. The study was carried out starting from the squashing of immature anthers fixed in acetic-ethanol and stained with orceine. The viability of the pollen was determined in agar and sucrose microculture. The most frequent abnormalities in meiosis I were: chiasmata not finished between big homologous, and precocious displacement of small chromosomes, one or more solitary or accompanied dicentric bridges with acentric fragments. In meiosis II, the occasional presence of bridges and fragments was observed, just as additional microspores. Chromosome breakage, crossing-over errors and heterozygotic paracentric inversion between greatest homologous are discussed like possible causes of the observed meiotic irregularities.

Palavras-chave : Aloe vera; meiosis; microsporogenesis; chromosomes; dicentric bridges; acentric fragments; pollen.