Physiological performance of Garcinia gardneriana (Planch. & Triana) Zappi: a species with recalcitrant and dormant seeds

Desempenho fisiológico de sementes de Garcinia gardneriana (Planch. & Triana) Zappi: uma espécie com sementes recalcitrantes e dormentes

Abstract:

Garcinia gardneriana (Planch. & Triana) Zappi is a native species widely distributed in Brazil. It has ornamental features, edible fruits, and its leaves have medicinal properties; however, its potential has not been explored. The aim of this study was to evaluate seed physiological performance due to dormancy, desiccation and storage tolerance. Only decoated seeds germinated. Seeds had an initial water content of 1.07 g H₂O.g^-1 dw and final germination of 95%. Both desiccation to 0.67 g H₂O.g^-1 dw and storage at 25 ºC for ninety days resulted in decreased germination, 43 and 41%, respectively. Desiccation below 0.25 g H₂O.g^-1 dw and storage for ninety days at 5 ºC were lethal. A rapid decrease in enzymic protection by superoxide dismutase and ascorbate peroxidase was correlated to desiccation sensitivity. Total polyamines content was higher in fresh seeds and markedly decreased with desiccation. The decrease in enzyme activity and polyamines content seems to be associated with seed viability loss. In sum, G. gardneriana seeds have a low tolerance to desiccation and are sensitive to chilling. Therefore, the seeds can be categorized as recalcitrant and dormant, a rare combination in terms of seed biology.

Index terms:
antioxidant enzymes; desiccation tolerance; physical dormancy; polyamines; germination