A CHARACTERISTIC ANALYSIS ON THE REPRODUCTIVE TRENDS FAVOURED BY ANTHER AND POLLEN GRAINS OF XANTHOPHYLLUM ARNOTTIANUM WIGHT (POLYGALACEAE)

摘要

Southern Western Ghats belongs to the family Polygalaceae and the genus is distributed along the riparian belt of Indo-Malaysian tropics. The flowers of Xanthophyllum highly resemble to those of keeled flowers and show inclination towards entomophify.Though cross pollination is preferred, self pollination was also observed. The anthers dehisce pollen grains two days before anthesis and the stigma becomes receptive one day prior to anthesis constituting protandry. Thus morphology and other pollen characteristics such as viability and germination of pollen grains of the flowers of Xanthophyllum were related to their role in pollination mechanism. The maximum percentage of pollen germination and pollen tube elongation was noticed in Brewbaker and Kwack's medium with 50% sucrose after 24 hours of incubation. The viability of pollen grains was checked at different periods of flower development in order to determine the optimum viability to effect a successful fertilization. The morphological and functional characteristics of the pollen grains are discussed in terms of anther and pollen morphology, pollen viability and pollen tube germination in vitro.