This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by Kamienska, A. Articles by Pharis, R. P. Search for Related Content PubMed PubMed Citation Articles by Kamienska, A. Articles by Pharis, R. P. Agricola Articles by Kamienska, A. Articles by Pharis, R. P.

Articles

Endogenous Gibberellins of Pine Pollen

II. Changes during Germination of Pinus attenuata, P. coulteri, and P. ponderosa Pollen ¹

^a Department of Biology, University of Calgary, Calgary, Alberta, T2N 1N4, Canada

The endogenous gibberellins (GAs) of pollen of Pinus attenuata, P. coulteri, and P. ponderosa were bioassayed at hour 0, 3, 15, 24, 48 and 72 of germination. Dormant pollen showed relatively high GA activity throughout the elution spectrum (i.e. ranging from relatively nonpolar to highly polar). The maximum GA activity was obtained at hour 15 in more polar regions and especially in the zone corresponding to GA₃ (for P. attenuata estimated as 250 micrograms of GA₃/kilogram pollen). It is probable that the "nonpolar" GAs present in high quantities in dormant pollen and in early stages of germination were converted to "more polar" GAs as germination progressed. The amount of all GAs decreased after hour 15 of germination and by hour 72 no GAs could be detected. Among the species tested P. attenuata showed the highest over-all GA activity.