COMPARISON OF ANTHER AND POLLEN DEVELOPMENT BETWEEN MALE-STERILE DIPLOIDS AND MALE-FERTILE TETRAPLOIDS IN PELARGONIUM ROSEUM

In Pelargonium roseule4 WILLD., the pollen of the diploid plant (2n=77) is abortive but its colchicine-induted tetraploid (2n=154) can produce fertile pollen. According to anatornical observations, there are no differences in the development and disintegration of tapetum as well as in the formation of microspores and young pollen grains between both ploidal plants. After the maximum enlargement of the extine pollen grains in the diploid become empty, while in the tetraploid plant pollen grains suddenly increase the volume of their cytoplasm at the time of tapetal disintegration. At the flowering time, each pollen grain in the tetraploid becomes bi- or trinucleated.