Vervaeke et al. 2002 (Conference Paper) Bromeliaceae

Controlling prefertilization barriers by in vitro pollination and fertilization of Bromeliaceae

Author(s):—I. Vervaeke, E. Parton, R. Deroose & M.P. De Proft

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

Publication:—Kluwer Academic Publishers. Printed in the Netherlands (2002). — DOI

Abstract:—Prefertilization barriers between different Bromeliaceae are mostly confined within the style. To control these barriers cut style, placental and placental grafted style pollination were studied. After cut style pollination the fertilization rate increased when a longer style part was left on the ovary of Vriesea C. Possibly less factors that control pollen tube guidance to the ovules are present in the lower style part. After placental pollination pollen germinated on the ovules but only rarely penetration of the micropyle by a pollen tube occurred. No difference in fertilization rate between compatible and incongruent pollination was found. Semi in vivo pollination resulted in a higher pollen tube growth out of the isolated style in comparison to semi in vitro pollination. However for Vriesea C, even after semi in vivo pollination pollen tube growth was inhibited at the stylar end. Grafting a style containing actively growing pollen tubes to the ovules on the placenta (placental grafted style pollination) resulted in a fertilization percentage, which was comparable to this after a classical pollination on the stigma for Aechmea A. Pollen tube growth through the style seems to be necessary for guiding pollen tubes to the ovule micropyle.

Keywords:—Bromeliaceae, cut style pollination, placental pollination, pollen-tube growth, semi in vivo pollination