ANATOMY, ABSCISIC ACID AND NUTRIENT CONTENT AND GERMINATION OF HELICONIA SEEDS

Abstract

Heliconias are asexually propagated through rhizomes and thus only few studies on their seed biology have been carried out so far. In this research we studied the anatomy of seeds and determined their abscisic acid and nutrient content, as well as their in vitro germination in four heliconia species: Heliconia bourgaeana, H. collinsiana, H. latispatha and H. psittacorum. The microscopical analyses of H. collinsiana and H. latispatha showed that, the seeds embryos appear without damages af- ter a year of storage; conversely, the embryonic tissues of H. bourgaeana and H. psittacorum presented alterations. In these species we detected the presence of tannins and starch in endosperm, with tannins being more abundant in H. bourgaeana and H. psittacorum. ABA content was much higher in H. collinsiana (7.8 μg g^-1 DM) than in the other species which had 0.26 μg g^-1 DM or less. Contents of B, Ca, Fe, Mg, Mn and Zn were also higher in H. collinsiana, whereas the lowest contents of B, Ca, Cu, Fe, Mg, Mn, P and Zn were found in H. psittacorum. At 85 d aft er sowing the in vitro germination was 18, 30, 3 y 32 % in H. bourgaeana, H. collinsiana, H. latispatha and H. psittacorum, respectively. We conclude that the four species vary in the level of reserve consumption from endosperm, in the presence of tannins and starch, in ABA, and macro and micronutrients contents and in the percentage of in vitro germination.