Aspectos da biologia floral e da polinização do adubo verde Mucuna pruriens (L.) DC.(Leguminosae, Faboideae)

Abstract

Green manure is considered a viable and sustainable alternative to agricultural land. The positive highlight this practice results from the proof of the harmful effects of joint-soluble fertilizers with high oil costs and industrial fertilizers. Thus Leguminosae family has been the most used as green manure, as it brings many advantages for both the soil and to the plants. In this family there is the Mucuna pruriens (L.) DC. (Leguminosae, Faboideae) species as one of the most used for this practice. However knowledge about their biology and especially in relation to aspects of floral biology and their pollinators about various species used as green manure are scarce. This study aimed to verify aspects of floral biology and pollination that influence the reproduction of green manure Mucuna pruriens. For this, we inventoried the wealth of floral visitors and pollinators; verified as morphology and floral biology influence the pollinator behavior and/or floral visitor; and analyzed the M. pruriens fertility components through its fruiting rates and seed formation. To study the floral biology flowers were observed as to their flowering time and duration of anthesis. Visa also is change of color in the floral parts and stigmatic receptivity at all stages of flower development. Morphometry of flowers by the material preserved in FAA and in natura was verified. For the morphological and anatomical study of the keel light microscopy and scanning electron microscopy was used. The floral visitors were observed during their foraging activities and made autogamy test for the presence of spontaneous self. For fertility components was observed a difference in fruit development positions in the basal, middle and apical inflorescence and the difference in the formation of seeds in the fruits positions. The M. pruriens flower anthesis have seven days. Are heteroclamídeas with purplish corolla dialipetala and zigomorfa. It is a monoecious plant with androecium and gynoecium diadelfo simple. The gynoecium and androecium are tensioned and confined inside the keel. In Keel apex petals are joined and lignified presenting a membrane that is different from petalar tissue. Were observed individuals Trigona spinipes (Fabr.) (Hymenoptera: Apidae) and Vespidae of individuals presenting looting behavior. There was no significant difference between the number of fruits developed in relation to the position in the inflorescence. Selective abortions occurred at a higher frequency in the basal region of the pods of Mucuna pruriens. Mucuna pruriens, presented characteristics that distinguishes it from other species of the genus, since, it showed no need for pollinators for reproduction by the presence of autogamy. The presence of the membrane in Keel vertex possibly be the difference that provides the reproduction of this species. Before the study of fertility components, it is possible to detect certain reproductive problems. There is a great investment in production M. pruriens little flowers to fruit formation occurring a great loss of energy descent to ensure species.