Vervaeke et al. 2003 (Article) Fertilization, pollination

Flower Biology of Six Cultivars of the Bromeliaceae II. Pollination and Fertilization

Author(s):—I. Vervaeke, R. Delen, J. Wouters, R. Deroose & M.P. De Proft

Corresponding email:—ine.vervaeke@agr.kuleuven.ac.be

Publication:—Selbyana 24(1): 87-94. (2003)

Abstract:—In describing the pathway followed by the pollen tube after compatible pollination, the authors found that pollen grains germinated on the papillate stigma and grew down in the style across stylar canal cells. They observed in the style of Vriesea splendens, a conversion from a hollow to a solid area at the lower end of the style. The pollen tube pathway of V. X vimimalis-rex X carinata and V. splendens differed from the universal pathway via the placenta described in literature and found by the authors for Aechmea fasciata and Guzmania Ungulata. Fertilization occurred porogamously in all studied species. Pollen tubes of A. fasciata grew at 2 mm/hour, with those of the other cultivars at 1.1 mm/hour. The time between pollination and start of pollen tube growth was 5-6 hours for Vriesea. Aechmea fasciata was inter-com- patible and, in part, self-compatible. The self-incompatibility index of A. fasciata decreased from 28% to 4% toward the end of the flowering period. Homomorphic gametophytic self-incompatibility is proposed for A. chantinii and for Tillandsia cyanea.

Keywords:—Bromeliaceae, incompatibility, fertilization, pollen tube growth, pollination