This study assessed morphological and genetic diversity in twelve Berberis F2 populations. Seeds were collected from selected F1 hybrids resulting from crosses between Berberis integerrima, B. crataegina, and ‘Zereshk Bidaneh’-a commercial seedless barberry cultivar. Initial evaluations compared seed germination and seedling survival on three substrates: perlite, cocopeat, and peat moss. Germination rates varied widely among F2 populations, ranging from 17% to 95.48%. A 1:1 mixture of cocopeat and perlite significantly enhanced germination. Twelve morphological and vegetative traits were subsequently measured, revealing substantial phenotypic variability across F2 populations. Correlation analyses identified strong positive associations among key traits such as leaf number, plant height, and leaf morphology characters. Factorial analysis indicated that the first two factors explained 35.5% of the total variance, primarily differentiating populations based on leaf pigmentation and leaf-spine architecture. Heatmap clustering grouped the F2 genotypes into six distinct phenotypic clusters. Notably, traits such as leaf margin spine (CV =33.89%) and leaf pigmentation (CV > 43%) exhibited high coefficients of variation, suggesting the potential for transgressive segregation and providing a wide basis for selection. These findings establish a robust framework for early-stage selection in barberry improvement programs.
