Morphological and anatomical characterization of peduncle, flower and fruit related to easy fruit abscission of Capsicum chinense (Solanaceae) genotypes

The sweet and chili pepper species of the genus Capsicum are originally from America; however, currently they are grown worldwide. Although widely appreciated, especially in the Amazon region, there have been few studies about C. chinense. Characterization and classification studies can aid in pepper crop genetic breeding and development of new cultivars with characteristics of agronomic interest. Resistance to fruit abscission makes harvesting difficult, which today is essentially manual, so that development of cultivars with easy fruit abscission, allowing semi-mechanized and mechanized harvest is an important goal. Descriptions of genetic differences based on anatomical characters are rare in this genus. Along this line, we examined morphological characters and anatomical structures directly related to easy fruit abscission in C. chinense, through the evaluation of two genotypes contrasting for this character, maintained by the Embrapa Hortalicas Genetic Breeding Program, as well as an F-1 hybrid. The morphological characterization of flowers and fruits was performed using 13 descriptors, eight defined by the International Plant Genetic Resources Institute and five adapted for this study. The anatomical characterization of the peduncle and flowers was carried out with the elaboration of plant slides to examine structures possibly linked to easy abscission of the fruit. Contrasting morphological polymorphisms were observed in immature fruit color, fruit shape, fruit position on the plant, abscission and fruit firmness, as well as fruit diameter, number of locules and seeds per loculus. Small differences were observed in the anatomical structures of peduncle and flower, such as the shape of the vascular system and lignification of the pericycle, but none were directly related to fruit abscission. Although there was no significant anatomical relationship with fruit abscission, the morphological characters evaluated in this study revealed great genetic variability for these genotypes, demonstrating potential of these genotypes in a breeding program for developing varieties with easy fruit abscission.