Pollen grain of barley (Hordeum vulgare L.) - pattern of development

Abstract

Pollen development in barley follows the general pattern established for other species of Poaceae: 1) microspore division occurs at the vacuolate microspore stage with polarly located nucleus; 2) microspore mitosis is immediately followed by phragmoplast and cell plate formation; 3) in consequence or unequal microspore division, the generative cell, at first attached to the pollen wall, is separated from the vegetative cell by a callosic wall; 4) during the postmitotic two-cell stage of development, the vegetative nucleus migrates to the aperture pole and is followed by the generative cell that is detached and free of callose wall. In this position the generative cell divides into two sperm cells. These data do not confirm the interpretation of pollen grain development in barley given by Cass and Karas in Can. J. Bot. 53: 1051-1062, 1975.