PALYNOLOGICAL STUDY OF SALIX L. (SALICACEAE) IN IRAN

Pollen grains in seven species of Salix are studied with light Microscope and Scanning Electron Microscope. The results of LM showed that pollen grains are tricolpate and the overall shape is spherical to subprolate. In polar view, most of pollen grains were 3-lobed with convex lobes. The size of pollen was very variable. The Exine was reticulate. The characters of muri such as shape and size of lumen were varied in different species. The lumen was isodiametric or heteromorphic and the patterns were orbicular, elliptic or polygonal with rounded angle. Based on former studies the pollen grains in this study were referable to the following types: Salix alba type 6, S. issatissensis type 1, S. acmophylla, S. zygostemon and S. cinerea type 2, S. elbursensis type 5, S. excelsa type 3 and 6. Our results showed that shape and size of pollen grins are similar but the exine sculpturing is different and can be used for distinguishing the species. In addition, the exine pattern in S. zygostemon which is a hybrid species showed that S. cinerea is the male parent of this hybrid and the female parent is S. elbursensis.