Morphological Characterization of Pollen in Some Varieties of Walnut (Juglans regia)

ABSTRACT In this study carried out to determine the pollen characteristics of walnut, Bilecik, Chandler, Fernette, Fernor, Kaman 1, Pedro, Şebin, and Şen 1 varieties were used as material. As a result of scanning electron microscopy (SEM) examination it was stated that the pollen shapes were oblate spheroidal for all the walnut varieties. The pollen of the varieties exhibited diversity in pollen length (37.54–40.52 µm), width (41.10–45.02 µm), pori diameter (2.45–3.61 µm), distance between pori (11.28–14.41 µm) and spinules (0.54–0.73 µm), pore (16.40–23.00) and spinules (20.50–43.50) number, spinule width (0.18–0.26 µm) and length (0.09–0.28 µm). Results showed that in particular, the Fernor had the largest pore diameter, so their number per unit area was low. In contrast, Bilecik had the smallest pore diameter. Distance between pori of this variety was the least. Therefore, a large number of pori was observed on the surface. In addition, spinules sizes were determined to be larger in Şen 1, but smaller in Chandler variety than the others. In particular, these morphological properties of pollen can be used for identification of different varieties. Also, the pollen shape and exine patterning of the varieties studied were illustrated by SEM images.