Métodos de superação de dormência em sementes de jaracatiá (Vasconcellea quercifolia)

Abstract

Jaracatiá (Vasconcellea quercifolia) is a native plant from Brazil, with great potential for use in human and animal feed. The species have been studied for use in plant breeding due to their natural resistence to diseases and low temperatures while others species of the same family are suceptible. Nowadays, great difficulties are found on plant propagation of Vasconcellea quercifolia and there is not avaliable studies about the seed dormancy. The present study aimed to evaluate different ways of seed preparation and pre-sowing to break the dormancy and their resistance to drying. It was used the temperature of 25ºC for a period of five days to dry seeds. It was avaluated the sarcotesta interference and different ways to extract the sarcotesta as well as the gibberellic acid effect on vigor and seeds germination. We adopted the factorial design squeme (2x5), consisting of two levels of humidity seeds. The drought seeds were incubated for five days at 25ºC to stabilize the humidity in 8%, with ar without sarcotesta, the remained seeds with humidity of 40% and 80% with or without sarcotesta. The association of five treatments were compared: Seeds without sarcotesta remotion (control), sarcotesta remotion with water for 24 hours, sarcotesta remotions with water and sand, sarcotesta remotion with water and sand + 500 ppm of giberellic acid and sarcotesta remotion with water and sand from fruts in stage of deterioration. It was avaluated the rate of seeds germination and vigor from the rapide germination index and emergence tests. The sarcotesta remotion in water for 24 hours and remotion with water and sand + 500 ppm of giberellic acid showed the Best results for germination rates, however with the respect to the vigor, only the association of giberellic acid in dry seeds were efficient for the elevation of germination speed, however the values of seed emergence were not significant.