Karyotypic Variability in Experimental Diploid and Triploid Hybrids of Aloe vera×A. saponaria

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.