Fruit biometry, germination and seed vigor of Mimosa setosissima Taub.: conservation of a rare Cerrado species

Abstract

Mimosa setosissima is a tree species, considered rare once its occurrence is restricted to the Cerrado biome. Studies on this species may contribute to its conservation. Thus, the objective of this study was to characterize the fruits (physically) and seeds (physiologically) of M. setosissima to provide supporting information for the commercial and conservational propagation of the species. The pods (n=200 fruits) of M. setosissima were collected from plants present in the Cerrado Rupestre of the Serra dos Pirineus State Park, Goiás, Brazil. The fruit were separated into two maturation classes regarding to the color and texture of the pods (brown and green). The pods of each maturity stage were characterized by the following attributes: fresh weight, length, width, thickness, number of seeds, number of normal and abnormal seeds (dead/rotten/damaged/broken). A germination test was used to evaluate the physiological potential of seeds. The germination test applied in a factorial (2 × 2) randomized design, with two fruit ripening stages (brown and green) and two substrates (between paper and paper roll and on paper in a gerbox) (temperature 25ºC; 12-hour photoperiod; humidity 75%). The morphobiometrics of M. setosissima fruit depends on the maturity stage, where an increased growth was observed in brown fruits. The substrate “between paper and paper roll” is more appropriate to conduct the germination test of seeds M. setosissima. Seeds coming from green pods have a physiological performance higher than that of brown seed pods.