Influence of Borate and Pentaerythritol Concentrations on Germination and Tube Growth of Lilium longiflorum Pollen1

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 H 3 BO 3 in the medium and stimulation in rate of pollen tube growth, with 30 μ m H 3 BO 3 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.