Análisis del cariotipo del híbrido natural Aloe x spinosissima y de sus parentales Aloe arborescens y Aloe humilis, mediante bandeo cromosómico C, CMA y DAPI

AUTOR(ES)
FONTE

Rodriguésia

DATA DE PUBLICAÇÃO

2017-09

RESUMO

Abstract The karyotype of three species of Aloe was studied with C-Giemsa, CMA (Chromomycin A3) and DAPI (4'-6-diamino-2.fenildol) chromosome banding in order to make contributions in their cariomorfometría, location, size studied bands, and discuss cytogenetic evidence of hybrid origin reported in A. x spinossisima. The entities studied have a 2n = 2x = 14 with two pairs of NORs (nucleolar organizer regions) with associated satellites and constitutive heterochromatin CMA + DAPI- (G-C rich regions). The amount of heterochromatin, expressed in % of the total length of the karyotype (LTC), varies between species: 1.92% by A. arborescens, 1.69% in A. humilis and 1.41% in A. x spinossisima. The bands are observed in the long arms of L2 and L4 of A. arborescens, in L3 and L4 of A. humilis and A. x spinosissima in the pair L4 and one of the supplements L2 and L3 one. A. x spinossisima presents values of LTC haploid and amount of constitutive heterochromatin intermediate between species designated as progenitor. These results and the notorious heteromorphy between different chromosome pairs, supports the hypothesis of the origin of A. x spinosissima, as a hybrid species from the natural crossing of A. arborescens x A. humilis.

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