Variations In Desiccation Tolerance In Seeds Of Eugenia Pyriformis: Dispersal At Different Stages Of Maturation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Eugenia pyriformis Cambess., known locally as uvaieira, a species of fruit-bearing tree with both pharmacological and gastronomic potential, has seeds which are sensitive to desiccation. The aim of this study was to analyse whether the degree of tolerance to desiccation of uvaieira seeds depends on the stage of maturation of the seeds at shedding. This, in turn, depends on the environmental conditions in which the seeds develop, including the accumulation of degree-days and rainfall in the period. Seeds were collected from the ripe fruit of parent plants located in the states of São Paulo and Minas Gerais, Brazil, submitted to drying and analysed for water content and germination. A completely randomised design was used in a 20 × 3 factorial scheme (source of material x level of drying). The degree of desiccation tolerance differs between region and period of collection, even for the same parent plant when the seeds are collected in different years. The water and thermal conditions of the environment during seed development modify the maturation cycle, the physiological quality and the acquisition of desiccation tolerance. In uvaieira seeds, desiccation tolerance depends on the physiological maturity of the seeds at the time of dispersal, which is associated with the environmental conditions.471118126CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Respiratory rates of inga vera willd. subsp. affinis (DC.) T. D. penn. seeds

The deterioration process of recalcitrant seeds is not fully known, mainly regarding the relation between fungi activity and respiration. Inga vera seeds are characterized by their high degree of sensitivity to desiccation and for only maintaining viability for a few weeks. The objective of this study was to identify the fungus action on respiratory metabolism of I. vera embryos subjected to chemical treatment in order to extend their storability. The results showed that the presence of fungi increases embryo respiration rate, thus affecting their conservation during storage. Treatment with carbendazin + thiram, especially at a dose of 200 ml per each 100 kg of seeds, was effective in controlling fungi, reducing the respiration rate and metabolism of I. vera embryos, increasing the maintenance period of their viability in storage26