Pollen-pistil interaction in a non-pseudogamous apomict, Commiphora wightii

Abstract

Structural and cytochemical details of the pistil and the interaction of pollen and pistil were studied in a non-pseudogamous apomict,Commiphora wightii.The anthers in the male and bisexual flowers produce functional pollen grains. The stigma is of the wet and papillate type. The style is typically solid with two strands of transmitting tissue that traverse the entire length of the style. There is a marked reduction in the area occupied by the transmitting tissue from the stigma to the base of the style. The cells of the transmitting tissue are isodiametric in transverse as well as longitudinal section and do not form longitudinal files of elongated cells as reported for other taxa. Proteins could not be localized in the intercellular matrix. Although pollen grains germinate on the stigma, pollen tubes do not grow beyond the proximal one third of the style. Changed orientation of the cells of the transmitting tissue and absence of proteins in the intercellular matrix could account for the failure of the pistil to support pollen growth.