Biologia floral de Physalis peruviana L. (Solanaceae)

Abstract

Physalis peruviana L. (Solanaceae) is an important crop in the small fruit sector due to its high added value. Considering that floral morphology and biology are determinants of plantpollinator interactions, this study aimed to describe P. peruviana anthesis through the recording of flower structure measurements, flower opening times, stigma receptivity, dehiscence of the anthers, the volume and concentration of the nectar. The study was developed in the experimental area of the Fronteira Sul Federal University, Cerro Largo, RS campus. Flower buds (N = 24) were marked to verify the flowers duration. The accumulated volume (N = 28) and nectar concentration (N = 63) were recorded with 10 μL graduated Microsyringes and manual refractometer, respectively. The flowers of P. peruviana last three days and open and close each day. During the anthesis there were changes in the size of the floral pieces. The flowers open around 6am and close around 6pm. The stigma was receptive from the beginning of anthesis to the senescence of the flower. The dehiscence of the anthers was sequential, with an average of three anthers open on the first day, 3.4 on the second and five on the third. There was a decrease in volume and concentration of nectar over the three days of anthesis: the volume ranged from 1.8 μL to 0.9 μL, and the concentration ranged from 22.9% to 20.5%. The sequential opening of the anthers and the continuous availability of nectar can be considered a strategy of P. peruviana, because through this mechanism the plant can contribute to increase the frequency of visits to flowers, which associated with stigma receptivity, throughout the anthesis, can facilitate cross-pollination, benefit crop breeding and productivity.