Variability of 21 apricot (Prunus armeniaca L.) cultivars and hybrids in selected traits of fruit and stone
Weight, height, width and diameter of fruits and stones were evaluated in 21 apricot cultivars and hybrids in 1994–1997. Statistically significant differences between the measured values of traits confirmed their applicability for objective characterization of genotypes. The evaluated traits are genetic dispositions. It was also proved by the rank of genotypes arranged according to the values of particular traits in one year that was highly significantly identical in the other years of the evaluated period (correlation coefficient r = 0.45<sup>++</sup> to 0.87<sup>++</sup>). The relationship between fruit weight and other traits (stone weight, stone height and stone width) is not linear. Fruit weight increases (or decreases) faster towards the limit values of traits. The average percentage proportion of stone weight in fruit weight ranged from 4.9% to 9.6% in the genotypes over the period of four years. A lower proportion of stone in fruit weight is a positive trait for selection of suitable genotypes for direct consumption and flesh processing. This trait can also be a suitable criterion of genotype selection to breed cultivars with a low proportion of inedible part. Promising cultivar Lemeda is an example of the low stone proportion in flesh weight. A high level of variability was found in the values of stone and fruit weight (coefficient of variation v = 19.00% and v = 24.74%, respectively). Coefficients of variation for other traits (fruit and stone height, width and diameter) were by more than a half lower.