Indian Journal of Plant Genetic Resources

The morphobiometric characters of the pollens and mericarps of 74 accessions of Origanum syriacum L. collected in the Damour River area of Mount Lebanon, Lebanon, were studied for the first time. The detailed analysis of the morphobiometric descriptors and the further elaboration of these by means of cluster analysis distinguished two principal groups. These groups seem to correspond to the two varieties of O. syriacum described by letswaart (1980), viz., O. syriacum L. var. syriacum and O. syriacum L. var. bevanii (Holmes) letswaart. On the other hand, with regard to their pollen characteristics, the studied accessions could be considered as ecoform variants. The greater uniformity detected in pollen traits could be ascribed to the enthomogamic pollination mechanisms present in Origanum syriacum and the related gene flow taking place among the populations under study. It can be hypothesized that such mechanisms might have in fact contributed to the natural selection of these populations, favoring greater uniformity in pollen traits rather than in those related to the mericarps. The diversity detected by this study in mericarps and pollen grains represents a useful diacritic element for the better understanding of Origanum syriacum, suggesting at the same time the presence of genetic variation that could be exploited in crop improvement programmes targeting this species.