The pollen grains are covered with two concentric wall layers, the outer exine and the inner intine. The stratification of pollen wall is primarily based upon optical microscopy of whole as well as sectioned grains and upon staining reactions of the strata. Recently such stratification is complemented by the biochemical analysis of the various pollen wall layers. The intine is [...]
In this article we will discuss about the role of proteins in pollen grains. T. Singer and Petrovskya - Baranova (1961) were the first to show the existence of proteins with enzymatic properties in certain layers of the pollen walls of Paeonia and Amaryllis. Subsequently, Makinen and McDonald (1968) demonstrated the pollen enzymes and isoenzymes in flowering plants. The details [...]
In this article we will discuss about the evolutionary trends among pollen grains based on palynotaxonomical works. Primarily the aperture is proximal in position in all the taxa of plants, and a change from proximal to distal has been conditioned by physiological and ecological needs that arose in the wake of the origin of new plant taxa. The bryophytes and [...]