ABSTRACT Seed predation is a natural phenomenon that can occur either before or after dispersal and can significantly reduce the economic value and reproductive potential of plants. The babassu palm (Attalea vitrivir, Arecaceae) is important to rural communities that extract oil from its fruits for a wide variety of uses. We evaluated the predation and germination of A. vitrivirseeds in Pandeiros River Environmental Protection Area (EPA-Pandeiros) in Minas Gerais State, Brazil. Sixty individual plants were evaluated to determine their fruiting patterns. Seed predation and germination were evaluated in the natural environment for eight months for fruits divided into two treatments: scarified and intact. Germination of fruits submitted to these same treatments was also evaluated under greenhouse conditions. Our results indicated that fruiting is continuous in this species and that fruit morphology does not influence either germination or predation. Likewise, fruit scarification did not influence seed germination. Pachymerus cardo (Coleoptera: Chrysomelidae) preferentially oviposited on scarified fruits, but only after their dispersal. The predation rate in the natural environment was 14.6%. Germination was not observed under natural conditions, but reached 33.05% under greenhouse conditions.

Rock field plant species present several adaptations to the climatic characteristics and seasonality of this habitat. In this study, we evaluate under field conditions the seasonal changes in non-structural carbohydrate accumulation in tuberous organs of Gomphrena marginata. Tuber fragments of plants of G. marginata were sampled monthly for a year (August 2010 to July 2011) in a rock-field area in southeastern Brazil. Quantitative analyses of total fructose, fructo-oligosaccharides, fructo-polysaccharides, reducing sugars and free proline were carried out. Qualitative analyses of carbohydrates were also performed by thin layer chromatography (TLC) and high performance anion exchange chromatography (HPAEC/PAD). Soil moisture was evaluated by gravimetry and plant water status was evaluated by measuring the relative water content (RWC) and water potential (Ψw) of underground organs. Throughout the analyzed period, a well-marked seasonality of fructan accumulation was observed in tuberous roots of G. marginata correlating significantly with seasonal changes in soil water availability. In the rainy period (October to February), the content of fructo-polysaccharides decrease while during the dry and quiescent growth period (April to September) a high accumulation of fructo-polysaccharides was observed without changes in the RWC of tuberous roots, suggesting that cell osmoregulation contributed to water status maintenance in G. marginata. Our study presents a second species of Amaranthaceae that accumulates fructans as its main reserve carbohydrate, which can be an important strategy for survival in an environment characterized by a long dry period.