Overcoming seed dormancy in Passiflora species

Abstract

The knowledge about aspects related to seed germination are extremely important to the propagation of Passiflora species. Considering the diversity of Passiflora species and the need of studies that can elucidate the germination process of Passiflora seeds this study aimed was to evaluate methods to overcome seed dormancy in two Passiflora species ( P. morifolia and P. cincinnata ) by pre-germinative treatments as physical scarification, immersion in gibberellic acid (GA 3 ) and Promalin ® (GA 4+7 + N-(phenylmethyl) -aminopurine). To dormancy overcoming, the pre-germinative treatments were: scarification in sandpaper; immersion in water at 50 ºC for 5 minutes; imbibition in 400, 1000, 2000 and 3000 mg L –1 GA 3 for 5 hours; scarification in sandpaper + imbibition in 400, 1000, 2000 and 3000 mg L –1 GA 3 for 5 hours; and imbibition in 0.03, 0.45, 0.90 and 2% Promalin ® for 6 and 12 hours. The treatments were distributed in a completely randomized design, with four repetitions of 25 seeds. The data were submitted to variance analysis and the averages compared by Tukey test and Scott-Knott, respectively, at 5% of probability using the software SISVAR. Germinability, germination time, germination velocity, uncertainty and germination synchrony were evaluated. The results showed that 0.45, 0.90 and 2% Promalin ® for 6 and 12 hours were effective to overcome the seed dormancy in P. cincinnata . The treatment 1000 mg L-1 GA 3 achieved the highest result to overcome the dormancy in P. morifolia seeds.