Variation in chemical composition and fruit morphometric traits of almond-leaved pear (Pyrus spinosa Forssk.) natural populations

Almond-leaved pear (Pyrus spinosa Forssk., Rosaceae) is a deciduous shrub or small tree native to Southern Europe and Asia Minor. The species is characterized by apple-shaped fruits which are quite hard and tart, but become sweet and edible after ripening. Given the importance of this wild species’ fruit, our aim was to study their morphological characteristics and chemical composition. Moreover, we tested the correlations between fruit characteristics and geographical and environmental conditions. To do this, we collected samples from 84 individuals across 10 wild populations located along eastern Adriatic coast. Overall, 15 morphological and six fruit chemical traits were examined. On average, fruits weighed 8.21 g, were 2.06 cm long and 2.54 cm wide, with stalks of 1.99 cm. Average values for seed length, width and thickness were 6.23, 4.40 and 2.69 mm, respectively. The largest percentage of fruits was water (68.90%), followed by glucose (3.98%), fructose (2.96%), protein (1.00%), ash (0.74%) and fat (0.12%). In addition, our research demonstrated high interpopulation variability, with statistically significant differences between the studied populations confirmed for nine morphometric traits and for water, ash, glucose and fructose content. Furthermore, we revealed that populations on higher latitudes with lower insolation rates tended to have shorter stalks, thinner seeds and lower glucose content unlike those from lower latitudes with higher insolation rates characterized by longer stalks, larger seeds and higher glucose content. Overall, our results can support gene conservation activities and breeding programs for this Mediterranean species under increasing pressure due to climate change.