Karyotypic Variability in Experimental Diploid and Triploid Hybrids of Aloe vera x Aloe saponaria

Abstract

Cytogenetic traits were examined in Aloe saponaria (2S), A. vera (2V and 4V), and the experimental diploid (VS) and triploid (VVS) hybrids. Karyotype 2n 2x 14 (8L 6S) was confirmed in 2S and 2V, whereas 2n 4x 28 (16L 12S) was ascribed to 4V. VS showed the expected karyotype 2n 2x 14 (8L 6S), with slight differences between the long (L) homologues. VVS also showed the expected karyotype 2n 3x 21 (12L 9S); however, several chromosome deviations reflecting the absence or addition of small (S) chromosomes, terminal deletions of variable size which led to the formation of atypical chromosomes, or the loss of a L chromosome were also observed. The implication of these karyological variations is discussed.