Discrimination between the cultivated species Passiflora edulis and the new species Passiflora cacao using trnL intron sequence, morphology and reproductive system
摘要
The genus Passiflora L. is the most important in family Passifloraceae, with more than 520 species. However, new species have been discovered and characterized. Many of these species are used as food, medicine, cosmetics and ornamentation. The cultivated passion fruit P. edulis Sims, also known as purple passion fruit tree, occurs in the Atlantic Forest of Southern Bahia state, Brazil. Another species was recently described, P. cacao, which is morphologically very similar to P. edulis. Their trnL intron sequence, morphology and reproductive system were characterized to better differentiate these two species. According to the comparison of the trnL intron sequence among species of the subgenus Passiflora, the P. cacao species was in a more basal position and more distant from P. edulis than the other species of this subgenus. Based on morphological descriptors for leaf, flower, fruit and pollen data, it was possible to structure the diversity found in P. cacao and P. edulis. Two distinct groups were formed, represented by the accessions of each species. Regarding on the pollen/ovule ratio, both species were included in the category of facultative autogamous but crossability percentages classified the species as allogamous. Passiflora edulis and P. cacao showed good crossbreeding rates, indicating that they are closely related species. Based on the comparison of the trnL intron sequence, pollen characteristics and vegetative morphology, P. cacao was included in the subgenus Passiflora group. Analyses based on the trnL intron sequence were effective in distinguishing between the two species and confirming the character of the individual genotype.