Multivariate Analysis of Morphological Variables in Berberis integerrima L., a Neglected Medicinal Fruit

Berberis integerrima L., commonly known as seedy barberry, is a significant member of the Berberidaceae family, known for its nutritional and medicinal attributes. In this study, the phenotypic diversity of 96 accessions of B. integerrima was investigated using 30 morphological traits, evaluated from the Jasb region in the Markazi province, Iran. One-way ANOVA (p < 0.05) revealed significant differences among the accessions. The coefficient of variation (CV) ranged from 11.34% (berry width) to 78.74% (berry shape), with 23 of the 28 traits (82.14%) having CVs greater than 20.00%, indicating a high degree of variation among the accessions. Leaf length ranged from 16.53 to 53.06 mm, while berry length varied between 7.03 and 11.58 mm, and berry weight was recorded from 0.05 to 0.37 g. According to the frequency distribution, shrub height was categorized into low (39), intermediate (34), and high (23) groups, while growth habits were identified as weeping (8), spreading (59), and upright (29), with spreading being the predominant habit. Canopy density and leaf density were classified as low (23 and 12), intermediate (59 and 70), and high (14), indicating their importance in optimizing light intake and enhancing plant health. According to principal component analysis, the first three components (PC1 = 10.59%, PC2 = 9.95%, PC3 = 9.52%) account for 30.06% of the total variation, highlighting their significant representation of the analyzed traits. The first 10 components explain 76.66% of the total variation. The correlation matrix analysis revealed strong positive correlations among several traits; for example, the correlation between leaf length and width was found to be 0.568**. Additionally, berry weight showed significant positive correlations with berry length (r = 0.553**), bunch weight (r = 0.709**), and berry width (r = 0.841**), highlighting the interconnected nature of fruit development. Hierarchical cluster analysis revealed that subgroup A2 exhibited the greatest morphological diversity, consisting of 43 accessions. The standardized beta coefficients obtained from the multiple regression analysis were supported by the principal component analysis. Consequently, the accessions "Jasb-7", "Jasb-40", "Jasb-17", "Jasb-41", and "Jasb-3" not only ranked among the first twenty promising accessions but also fell outside the 95% confidence ellipse, exhibiting distinct morphological and pomological traits. This indicates that these genotypes possess valuable potential for selection breeding programs. In particular, the unique characteristics of these accessions may offer new opportunities in both agricultural and medicinal contexts.