Characterization of the pollen growth transition in self-incompatible Petunia inflata

摘要: In Petunia inflata, as in other species that shed bicellular pollen, early pollen tube growth the pistil is slow, then increases 2- to 5-fold depending on genotype of female parent. We refer time point at which tubes enter accelerated phase transition (PGT). Here, we present evidence pre-PGT and post-PGT are quantitatively qualitatively different, PGT triggered when reach zone (TZ) below stigma. The capacity various zones precipitate was tested through 'stump' pollinations: varying lengths apex were excised, cut surface remaining (the stump) coated with stigmatic exudates dusted compatible pollen. Pollen applied TZ tissues entered earlier than growing intact control pistils; delayed stylar stumps, largely because germination reduced growth. immature pistils, by several hours relative its onset mature pistils. fails occur cultured vitro. Collectively, data suggest become competent they a critical size, but physicochemical environment transmitting tissue necessary for triggering cellular changes result An analysis distribution tips before after suggests competition most intense during phase.