Flower anatomy related to blooming development of Berberis microphylla G. Forst (Berberidaceae)

Abstract

Berberis microphylla G. Forst. is a Patagonian native shrub commonly named “calafate”, which has a growing economic potential due to its dark blue berries that are consumed fresh, as jams and preserves, and are used for the production of soft drinks and ice cream. Moreover, the fruits have a high content of carbohydrates, phenols and antioxidants. The objective of this work was to show the changes observed in the flower from the emergence in relation to the floral phases and the importance that they have on pollination and fertilization. During the anthesis, the nectar is excreted inside and outside of the petal through the epidermis of the secretory tissue. The epidermis of the stigma is papillae with cells of greater length in the periphery of this structure simulating an additional ring. Secretory tissue is also present on the area of the fusion carpel. During anthesis, the epidermis glands of the stigma showed active secretion and these conditions favor pollen grain germination. Germinated pollen grains were observed after 12 hours of pollination and ten days later the pollen tube reached the ovule area. Pollen tube grew surrounded the ovules and probably some of them already accomplished the fertilization.