POLLEN, TAPETUM AND ANTHER DEVELOPMENT IN TWO CULTIVARS OF SWEET CHERRY (PRUNUS AVIUM)

The ultrastructural development of pollen and tapetum is described together with the morphology of anther from the onset of meiosis up to the anther dehiscence in two cultivars of sweet cherry.Plastid differentiation and dedifferentiation together with starch metabolism was compared in tapetal cells and in microspore/pollen grains. Observations were carried out in two successive years and differences in the duration of the process were recorded. For one of the cultivars the whole process is presented in a reproductive calendar with emphasis on intaraction between anther tissues. The increase in diameter of microspore/pollen grains varies in the two considered years. Anther dehydration occurs due to the formation of an abscissing tissue.