Plant growth substances in pollen of Pinus radiata at different levels of germination

Publisher Website
Google Scholar
Abstract
Growth substances in germinated and ungerminated Pinus radiata pollen were examined by extraction and bioassay. Thirteen active substances were detected: five auxins, three inhibitors, four gibberellins, and one compound with some properties characteristic of both gibberellins and cytokinins. As the pollen germinated in vitro the quantities of some of these subtsances increased, others decreased, and still others remained constant. It is probable that the substance with both gibberellin and cytokinin affinities has a role in pollen-tube growth; and it is possible that, in vivo, one of the aqueous auxins may have a role in ovule development. Possible roles for some of the other hormones are briefly discussed.