Difference in Micromorphological Pattern on Pollen Surface of Japanese Pear Cultivars

The dry pollen surface of Japanese pear cultivars was investigated using the scanning electron microscope (SEM). Ridges, perlorations and nanoprocesses were observed on the exine, and the micromorphological pattern combined with these characteristics appeared to vary with the cultivars. Four cultivars, Imamuraaki, Suisei, Kikusui and Choju which apparently differed from each other with regard to the micromorphology of pollen surace, were chosen for estimating the morphological differences quantitatively. Twelve characteristics could be selected and measured on 50 pollen grains in each cultivar, based on microphotographs. Discriminant analysis was carried out using these 12 characteristics. Of the total of 200 pollen grains examined, about 76 percent could be correctly assigned to each cultivar. It is thus suggested that the micromorphology of pollen surface is available for distinguishing and identifying Japanese pear cultivars.