Pollen Tube Growth and Fertilization Efficiency in Salpiglossis sinuata: Implications for the Involvement of Chemotropic Factors

Abstract

The possible involvement of chemotropic factors influencing pollen tube growth in the style and ovary of Salpiglossis was studied. Pollen deposited at the base of excised styles germinated readily, with pollen tubes penetrating the transmitting tissue and growing towards the stigma, implying that no chemotropic requirement exists for pollen tube growth in the style. However, the position and high efficiency of seed set following limited-pollination of intact pistils would support the involvement of localized chemotropism operating within the ovary.