Stigma receptivity and dehiscence of pollen in an F3 generation of ornamental pepper

Resumo

The objective of this study was to evaluate stigma receptivity and dehiscence of pollen in three floral development stages in an F₃ generation of ornamental pepper (Capsicum annuum L.). A total of 162 plants were evaluated, divided into two classes according to the color of the corolla: purple and white. To study the stigma receptivity and anther dehiscence, three floral stages were analyzed: bud, pre-anthesis, and open flower. For each stage, 33 replicates of each phenotypic class were collected. The receptivity of the stigma was detected by dripping a hydrogen peroxide solution (3%) on it. For the evaluation of the level of receptivity, scores of 0 to 3 were assigned, varying according to the number of bubbles found on the stigmatic surface. As stigma receptivity was observed, anther dehiscence was also observed. Scores of 1 to 5 were assigned for the reference of the amount of pollen released by the stamens. The data were subjected to analysis of variance at 1% probability with later separation of means by Duncan’s test at this same probability level. For the analysis of divergence, the data were clustered according to Tocher’s method based on generalized Mahalanobis distance. After the analysis of the data, it was observed that the flower colors did not differ statistically for the presence of pollen grains. When open, both the white and purple flowers showed higher means for pollen dehiscence as compared with the other treatments, which did not differ statistically. The flowers from the ornamental peppers displayed stigma receptivity since the bud phase, but the highest level of receptivity was observed after anthesis. Anther dehiscence prevailed after anthesis of the flowers regardless of color, and the presence of pollen grains was superior after anthesis in all genotypes. For the manual crossing, the buds pre-anthesis are the most indicated irrespective of the color, as they show high stigma receptivity and greater ease at handling.