Fungicide And Drying Effects On The Viability Of Recalcitrant Seeds Of Inga Vera Subsp. Affinis

Studies on the health and quality of seeds from native tree species are scarce in the tropics, which is the case of Inga vera, a recalcitrant-seeded Brazilian species used in reforestation. In this study a series of experiments were conducted to analyze the effects of fungicides and hydration levels on the suppression of seed borne fungi and seed physiology. Firstly, three commercially available fungicide formulations (thiram, carbendazim + thiram and carboxin + thiram) for seed treatment were evaluated. Secondly, embryos were subjected to a combination of four drying levels (62, 52, 44 e 34 % water content) with or without fungicide (carbendazim + thiram). All three preliminary screened fungicide formulations were not phytotoxic, with carbendazim + thiram performing best. Seed deterioration was associated with a high incidence of fungi at any level of drying. Fungicide treatment reduced the incidence of the most common fungi (Acremonium curvulum and Phomopsis diachenii) and extended the lifespan of non-dried embryos from 90 to 120 days. © 2016, Sociedade Brasileira de Fitopatologia.41317718

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