AUTOINCOMPATIBILIDAD Y PROTANDRÍA EN POBLACIONES NATURALIZADAS DE ALOE VERA DE LA PENÍNSULA DE ARAYA, VENEZUELA

Abstract

The synchronization and compatibility of the
reproductive organs of Aloe vera (L.) Burm.
f. (Aloaceae) were evaluated by carrying out
crosses at different flowering stages and by
analyzing the germination response of pollen in saccharose-agar microcultures with
or without macerated stigmas and styles. In
vivo observations showed that A. vera does
not produce fruits following intraspecific
pollination, either between flowers of the
same plant or as a result of intra- or interpopulational crosses. However, the pollen from
A. saponaria Haw. (= A. maculata Medik.)
promoted the formation of fruits and hybrid
seeds in crosses performed from 1 to 4 days
after anthesis in the receptor flower. Pollen
germination and in vitro pollen tube growth
were significantly reduced in A. vera by the
presence of mother tissue, whereas in A.
saponaria there were no differences between
culture media. This research suggests the
existence of protandry in A. vera with at
least 24 h of disparity between maturation
of reproductive organs, and sporophytic selfincompatibility, the latter being favored by
the low genetic variability of the populations
under study.