Phenotypic variability of autochthonous walnut (Juglansregia L) genotypes in northwestern Bosnia and Herzegovina
: The main objective of this study was to examine the characteristics and the relationship between walnuts in the Una-Sana Canton based on phenotypic properties. This is the first study of preselection of walnut variability in this area. In this study, we evaluated the phenological and morphological characteristics of 75 selected genotypes during 2014 and 2015. Twenty-four phenotypic traits were monitored throughout 2 years on different sites. The results of the PCA analysis showed a very high heterogeneity of walnut seedlings on the examined sites, from the aspect of observed parameters. A limited number of superior genotypes were found, but individual genotypes with high nut and kernel weight, as well as the colour of the kernel were determined, which would classify them as high-ranked parents in hybridization programs. Certain number of genotypes with high values of traits such as: nut weight, kernel weight and a high percentage of kernel were selected for future studies. Amongst the selected trees, genotype G25 had the highest weight of nuts and kernel, as well as a satisfactory color of the kernel. This genotype could be used as a superior tree for further breeding programs in the future. A highlevel of phenotypic variability in this studyrevealed the existence of a rich genetics pool of nuts variation. The genetic diversity of walnuts obtained from our studies will represent a valuable source of information for breeding programs of Persian walnut in future.