Rapid tube growth occurred when lily (Lilium longiflorum Thunb. cv. Ace) pollen germinated in a liquid medium containing 0.29 m pentaerythritol. Growth was reduced by increasing or decreasing the pentaerythritol concn. There was a hyperbolic relationship between concn of H3BO3 in the medium and stimulation in rate of pollen tube growth, with 30 μm H3BO3 causing one-half maximal stimulation of growth. Neither early pollen tube growth nor percent germination was stimulated by the hormones indoleacetic acid and gibberellic acid, nor was there any effect by 2’-isopropyl-4’-(trimethylammonium chloride)-5’-methylphenyl piperidine-1-carboxylate (Amo 1618), an inhibitor of gibberellin biosynthesis.
This report describes a rapid and convenient photomicrographic method to observe pollen germination. The method was developed in connection with studies of biochemical changes during germination. It was important to know the time of pollen tube initiation and approximate rate of pollen tube growth. The technique was used to study germination of lily pollen (Lilium longiflorum, cultivar Ace) in sucrose.