Localization of membrane-associated calcium in unpollinated and pollinated pistil of Petunia hybrida Hort.

Elżbieta Bednarska


In the pistil of Petunia hybrida, the transmitting tract and the ovules are the sites which give Ca2+-CTC fluorescence. In unpollinated pistil the level of membrane-associated Ca2+ decreases from the stigma to the base of the style. The renewed strong rise of Ca2+-CTC fluorescence appears on the placenta surface and in the ovule integuments. Following pollination, when the pollen tubes have grown through the pistil, the pattern of membrane-associated Ca2+ on the path stigma - ovary is reversed. The highest fluorescence is found in the base of the style. In pollinated ovules the Ca2+-CTC fluorescence increases markedly. In the transmitting cells membrane-associated Ca2+ occurs mainly in the polar regions of the cell. During cell degeneration following pollination the cytoplasmic clusters show Ca2+-CTC fluorescence. The used P. hybrida cultivar is self-fertile. The selection of pollen tubes occurs mainly in the upper part of the style. The rejected pollen tubes show a steady high level of membrane-associated calcium.


Petunia hybrida; calcium-chlorotetracycline; pollen-pistil interaction

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