When this article was originally published in Plant Genetic Resources it contained an error in the name of the author Majid Esmaeilizadeh. This has now been updated.
There was also a handful of errors in the content and citations for some tables and figures. These have been updated and corrected accordingly.
The authors apologise for these errors.

Figure 1. Nut and kernel characteristics of some studied walnut genotypes.
Table 5. Means comparison of quantitative traits of 45 studied walnut genotypes based on cluster analysis

*, ** According to the significance level in the probability level 5% and 1%.