Seed morphology and germination of Passiflora species
Image analysis, Passiflora alata, Passiflora cincinnata
The objectives of this research were to overcome the dormancy of seeds of Passiflora alata and Passiflora cincinnata MAST. as well as to evaluate the internal and external morphology of P. cincinnata seeds by X-ray test and image analysis using GroundEye® software, aiming to relate the seed morphology to their respective maturation stages and to establish the ideal moment for collecting fruits, associating with the quality of the seeds. To overcome dormancy, the pre-germinative treatments were: imbibition in Fluridone® in concentrations of 0,1; 10 and 100 µM, for 12, 24 and 48 hours; soaking in Promalin® in concentrations of 0,03; 0,45, 0,90 and 2%, for 6 and 12 hours. The treatments were distributed in DIC, with four replications of 25 seeds. Germination, meantime, germination speed index, germination uncertainty and synchrony were evaluated. The results revealed that in seeds of P. alata, Promalin® at a concentration of 0,90% in 12 hours of imbibition, guaranteed better germination results, average germination time and germination speed index. For seeds of P. cincinnata, treatment with Promalin® is effective at a concentration of 2% for 6 hours, promoting an increase in germination and the rate of germination speed. To perform the X-ray test and image analysis using the GroundEye® software, four replications of 50 seeds were used for each stage of ripening of the fruit of P. cincinnata (green, “from time to time”, mature and senescent). The seeds submitted to X-ray exposure were classified as full or empty. GroundEye® equipment was used for computer image analysis, evaluating 15 descriptors related to color dominance and 7 geometry. Subsequently, the seeds were evaluated for germination percentage. From the X-ray test, it was found that there was no statistical difference between the maturation stages. The results obtained by the GroundEye® software indicate differences in color and geometry between the fruit ripening stages. It is concluded that the seeds of P. cincinnata can be collected from fruits in the mature and senescent stages without prejudice to the physiological quality.