Micromorphological study on the seeds of wild species of Pyrus (Rosaceae) in Iran and their taxonomic implication

The seed micromorphological characters of 15 taxa of Iranian Pyrus comprising 22 individuals were examined by Scanning Electron Microscopy (SEM) and Digital Microscopy (DM) for the first time in this survey. For the assessment of probable ecological effects, several individuals of some widespread species were studied. After collecting several samples of each wild taxa of Pyrus from different localities in a ten-year period, the specimens were identified by means of the examination of type specimens and different Floras. After the examination of the seeds surface, qualitative (e.g., shape and ornamentation of seeds including areolate, foveate, reticulate, colliculate, striate and undulate types) and quantitative characters (e.g., size of seeds, size of surface cells and thickness of cell walls) were assessed. Statistical analyses were performed on the data using SPSS software. According to these observations, seed morphological characters showed to have a considerable variation even among the different individuals of the same species, verifying complexity of the genus as revealed by the different approaches which were previously reported. However, some descriptive characters of seeds such as shape, size, surface ornamentation type, cell size and cell wall thickness are presented for the first time for the genus.