DIVERSITY AND EVOLUTION OF POLLEN APERTURE PATTERN IN ANGIOSPERMS

Srihari Reddy Devarinti; A. Vijaya Bhasker Reddy

Volume : V, Issue : XII, December - 2016

DIVERSITY AND EVOLUTION OF POLLEN APERTURE PATTERN IN ANGIOSPERMS

Srihari Reddy Devarinti, A. Vijaya Bhasker Reddy

Abstract :

?e wall of pollen grains particularly outer wall exine shows impressive ornamentations and morphological variation. Diversity of aperture pattern in pollen is one of the main features of pollen morphology. ?is diversity is due to variation in pollen morphogenesis, which occurs during microsporogenesis. In monocots, pollen in many species is monoporate(monoaperturate), a single aperture located at the distal pole, but the shape of the aperture varies from monosulcate, trichotomosulcate to polychotomosulcate. But in dicots(eudicots), pollen is triporate(triaperturate) and three apertures are arranged in equatorial plane in most of the species and in remaining species di, tetra, penta or hexaaperturate. In Chenopodiaceae, Amaranthaceae, Convolvulaceae, Cucurbitaceae pollen is pantoporate/polyporate i.e. many apertures all around the surface of the pollen. Aperture pattern with reference to Borassus spp. belongs to Arecaceae of Monocotyledons and Phyllanthus spp. belongs to Leguminosae of Dicotyledons is shown