Morphological and cytogenetic characterization in experimental hybrid Aloe jucunda Reyn. x Aloe vera (L.) Burm. f. (Asphodelaceae)

Abstract

Aloe L. includes plants of economic interest worldwide for their medicinal properties and ornamental character. In this study, morphological and cytogenetic traits were evaluated in a hybrid obtained using Aloe jucunda Reyn. as pollen donor and A. vera (L.) Burm. f. as female parent, to characterize it, determine its ornamental and agronomic potentialities and aspects related to its reproduction. Conventional protocols for morphometric studies and cytogenetic analysis described for succulent plants were applied. Progeny showed intermediate expressiveness in most of the characteristics, except in the colour of the leaves and flowers (hybrid = A. jucunda), as well as for the length of teeth, number, and area of leaf spots and angle between continuous leaves, where it surpassed the expression of both parents, giving it a high ornamental value. The length, width, and thickness of the leaves improved with respect to the paternal genome, so its potential for the exploitation of the gel and latex of its leaves cannot be ruled out. Root tip cells showed a karyotype 2n = 2x = 14 = 8L + 6S = 1L(smsat) + 1L(sm) + 3L(st) + 3L(smsat) + 1S(m) + 5S(sm). Microsporogenesis showed chromosomal abnormalities in 47.4% of the meiocytes, the most frequent being micronuclei in prophase-I, sticky chromosomes in metaphase-I, one or two dicentric bridges accompanied or not by acentric fragments in anaphase-I, -II, and telophase-I, - II, as well as one or two additional microspores. These abnormalities reduce the fertility of their pollen grains and limit their sexual reproduction, providing a better explanation for their sterility.