Características morfoanatômicas, fisiológicas e bioquímicas de sementes de Parkia multijuga Benth. e Parkia pendula (Willd.) Benth (Fabaceae-Mimosoideae) submetidas a diferentes temperaturas

Abstract

Studies involving seeds of native species analysis has received attention in the scientific community, whether as result of destruction and degradation of brazilian ecosystems, or aiming attainment of information that reflect seeds physiological quality and their potential applications. Technically it is known that the success in the establishment of a species is related to the fact that their seeds can germinate rapidly and uniformly, winning the competition to other species or being able to remain viable for long periods until the conditions become favorable to germination and initial seedlings development. To this end, the energy source of vital processes and new tissues formation results of seeds reserves mobilization. In this sense, this study aimed to investigate and compare morphological, physiological and biochemical attributes of quiescent seeds of Parkia multijuga and Parkia pendula, as well as to investigate the effect of temperature on germination reserves mobilization. Thus, the following activities were developed: I) seeds morphological characterization (seed biometry and external and internal description), II) determination of the moisture content, III) anatomical and histochemical characterization of seed different structures, IV) germination physiology, V) biochemical characterization of carbohydrates, lipids and proteins and their developments, respectively (fatty acids, protein fraction and onedimensional electrophoresis), in order to elucidate the structural and functional alterations caused during germination. Results showed that species have distinct morphological patterns and that constant temperatures between 25 to 30 ° C for P. pendula and 30 to 35 ° C for P. multijuga favor higher percentage of seed germination, with the highest speed in a shorter period of time. Among the primary metabolites, carbohydrates as starch, correspond quantitatively to more stored reserves in the P. multijuga cotyledons seeds, while proteins are accumulated in greater quantities in P. pendula cotyledons seeds. The species have different concentrations of total soluble sugars, total lipids, total protein and protein profile while present similarity in fatty acids and proteins composition. Considering the results obtained for the metabolites analyzed in this investigation, was verified that despite belonging to the same botanical family and subfamily, these species have different strategies in the use of organic reserves stored in their cotyledons.