Morphometric Diversity for Rootstock Characteristics of Turkish Hazel (Corylus colurna L.) Populations in The Western Black Sea Region of Türkiye

The Turkish hazel (Corylus colurna L.) is native to Türkiye, where it is found only in small, scattered, and isolated populations within its natural distribution area. These remaining populations are of critical importance for conservation, for continued use as a natural reservoir, and natural selection. The trees are up to 400 years old and already well-adapted to harsh environmental conditions. In recent years, this species has drawn the attention of agriculture and forest practitioners and scientists in several countries who use this important and valuable tree species in studies of the effects of climate change. The origin and genotype of the reproductive material of this species play a key role in its adaptation to environmental conditions, and possible cultivation. The purpose of this study is to reveal the variation of genotypes selected from 13 different populations in Kastamonu and Bolu provinces in terms of rootstock characteristics. These regions are the locations where the Turkish tree hazel is most abundant. For this aim, the growth habit, vigor, number of suckers, and internode of one-year-old shoots were scored on the parent trees. A Kruskal Wallis-H test was applied to the non-parametric data to determine if there were differences among the populations for each variable and the total number of points. Then the Mann-Whitney-U test was used for differences among the groups. In addition, the phylogenetic relationship among the populations and genotypes was revealed by Cluster analysis. Among the rootstocks scored, KTU3 and KTU64 provided the highest score according to non-suckering and strong growth. It has been observed that individuals in Turkish hazelnut populations generally do not form suckers (%89.4) and show strong growth. C. colurna trees were observed to be individual and scattered in the population. Most of the trees are elderly and need to be protected in situ. Turkish hazel population will play a key role in production and sustainable such as to develop rootstock and variety in agriculture production, sustainable forest development, and for ecological adaptation in climate change scenarios.