Ecophysiological aspects of the germination of Physalis angulata L. seeds

ABSTRACT Physalis angulata L. (Solanaceae), known as ‘camapu’, has pharmacological and agroindustrial potentials, but information on the ecophysiological aspects that influence germination is scarce. In this context, the objective was to evaluate the expression of the physiological potential of P. angulata seeds as a function of the maturation stage, temperature, substrate and light condition. Four experiments were conducted: in the first, the maturation stages (green calyx + fruit, yellow calyx + fruit and light brown calyx + fruit) were evaluated at temperatures of 25, 30 and 35 °C, separately; in the second, the interaction between the temperatures of 35, 40 and 45 °C and types of substrate (on paper, between paper and between vermiculite) was tested in a 3x3 factorial scheme (temperatures as the first factor and types of substrates as the second factor); in the third experiment, the effect of light (absence of light, white light, red and far-red light) was evaluated; and, in the fourth, increasing values of photoperiods (0, 8, 12 and 16 hours) were used. In all experiments, the design was completely randomized with four replicates of 50 seeds. Analysis of the results showed that there was no interaction between the temperatures and the substrates tested, demonstrating the isolated action of the factors. P. angulata seeds expressed better physiological potential when the calyx and fruit are yellow. In the germination test, the seeds should be sown between paper towels, under temperature of 35 °C and absence of light.