Embriogênese adventícia em Eugenia uniflora L. (Myrtaceae).

The ovule of Eugenia uniflora is hemicampylotropous, unitegmic, crassinucellate with obturator tegumentary obturador. Vascularization of the ovule is formed by a bundle which penetrates the funiculus and suffers split forming two branches, one of which extends to the chalaza while the other goes to the vicinity of the micropyle. The nucellus has the extended apex forming a nucellar calyptra narrow and pointed. The mature gametophyte of Eugenia uniflora is the Polygonum type. The Embryogenesis begins in the period between 48 and 72 hours post-pollination. From the third day was observed two kinds of developing seminal in different ovules. In certain seeds the process is conventional, with a globular embryo, endosperm nuclear bulky, nucellus with vacuolated cells and dense cytoplasm on the fourth day after pollination. In other development type, were found bulky structures of circular contours, multicellular, with protoderm and surrounded by the endosperm in seeds of seven days post-pollination. These structures were interpreted as nucellar embryos. The development of these adventitious embryos is very fast and dependent fertilization suggesting the occurrence of competition for maternal resources. This hypothesis, if confirmed, could explain the low ratio seed / ovule in Eugenia uniflora.