Morphological variation in leaf & seed germination characteristics of Rowan tree (Sorbus aucuparia L.) in the Hyrcanian forest

Rowan is a tree with a very limited distribution in the upper treeline in the Hyrcanian forest. In this study, seven habitats of this tree from east to west of the Hyrcanian forest were identified and seed germination behaviors and diversity in leaf morphological traits were evaluated. Multivariate analysis showed that the studied populations were not differentiated from each other in terms of morphological traits. The results of germination percentage showed that in cold treatment and hot and cold treatment, germination reached about 100% after about 70 weeks. The germination rate in the cold treatment reaches its peak at week 55 and about 90% of the seeds germinate at week 55. In the hot and cold combination treatment, although before week 50 the germination rate reaches its maximum with a cumulative germination percentage of about 40%, but from this week to week 55 the germination rate again slows down and from week 55 to week 60 second drops. It experiences its peak with about 80% germination. The results of the present study showed that the Rowan tree species does not have a high morphological diversity in its habitats in the northern Iran. Due to lack of knowledge on the long-term seed germination of this tree, mountain nurseries have been unsuccessful in producing seedling