MORPHOMETRIC ANALYSIS OF DIOSPYROS SPP. FRUITS FROM THE KHOROL BOTANICAL GARDEN COLLECTION

Abstract

Background. The genus Diospyros L. (Ebenaceae) comprises approximately 787 taxonomically recognised species, primarily distributed in tropical and subtropical regions. Among the species introduced to Ukraine, D. kaki is the most widely cultivated, owing to its nutritionally valuable fruits, rich in sugars, antioxidants, and minerals. While D. kaki can tolerate winter temperatures down to -18 °C (and occasionally to -22 °C) in southern Ukraine, D. virginiana is the most frost-resistant species, tolerating temperatures as low as -37 °C, which enables its cultivation throughout the country. Hybrids of these species, developed in Ukraine, combine the large fruit size characteristic of D. kaki with the high winter hardiness of D. virginiana, thereby facilitating the northward expansion of high-quality persimmon cultivars.
Materials and Methods. The study was conducted at the Khorol Botanical Garden (Forest-Steppe zone of Ukraine) and included 18 persimmon genotypes. Plant material comprised D. virginiana seedlings and American cultivars (‘Early Golden’, ‘Meader’, ‘Prok’), alongside the Ukrainian interspecific hybrid ‘Sosnivska’. In 2025, morphometric analysis
was performed on a randomly selected sample of 20 fruits per genotype. Measurements included fruit weight and linear parameters (height, diameter, and shape index), as well as seed dimensions (length, width, and thickness) and weight. Data were processed using descriptive statistics, correlation analysis, and analysis of variance (ANOVA). Fisher’s least significant difference (LSD) test was used to determine significant diffe­rences (p ≤ 0.05).
Results. Significant morphological variability in fruit and seed characteristics was observed among the 18 studied genotypes. The ‘Sosnivska’ hybrid produced the largest and heaviest fruits, with a mean weight of 75.2 g, significantly exceeding all D. virginiana genotypes. Among the latter, ‘Prok’ exhibited the highest fruit weight (38.4 g), followed by ‘Krasotka’ and ‘Meader’, while certain seedlings produced the smallest fruits (under 10 g). Fruit weight and number of seeds showed high variability, with seed counts ranging from zero to eight. Strong positive correlations were identified between fruit weight and linear dimensions (r > 0.9), and between seed width and weight (r = 0.767). However, fruit weight exhibited no significant correlation with seed number (r = 0.129).
Conclusions. The substantial morphological variability observed within the Diospyros collection provides a solid basis for selective breeding. The hybrid cultivar ‘Sosnivska’ demonstrates the effectiveness of interspecific hybridisation, combining superior fruit weight with high environmental adaptability. Moreover, the absence of
a significant relationship between fruit weight and seed number (r = 0.129) indicates that breeding for larger fruits with reduced seed content is feasible, which is particularly important for both fresh consumption and industrial processing.