Abstract Quince ( Cydonia oblonga Miller) is a valuable fruit species with significant economic, nutritional, and genetic importance. The conservation and evaluation of genetic resources are crucial for plant breeding, and UPOV descriptors are commonly used as a standardized tool for their characterization, mainly focusing on morphological and phenological traits relevant to DUS testing. This study evaluated five quince genotypes selected from two central villages of Bilecik province, a previously unstudied region in Türkiye, based on 21 leaf and fruit traits. Variance analysis revealed significant differences for all traits, with the highest coefficients of variation observed in fruit: neck length (136.93%), fruit: neck (104.32%), and leaf blade: undulation of margin (81.31%), while leaf blade width (5.03%), leaf blade length (9.62%), and fruit length (13.54%) showed the lowest variability. Leaf blade size was greatest in YG-11-5, whereas fruit size and weight were highest in YG-11-1. Correlation and cluster analyses revealed strong positive relationships among fruit traits and negative correlations between fruit and leaf traits, highlighting trade-offs between vegetative and reproductive allocation. Genotypes were grouped into three clusters, emphasizing the predominant role of fruit traits in differentiation. These findings provide critical data for quince breeding and genetic resource conservation.
Gül et al. (Sun,) studied this question.