Analysis of Agromorphological Descriptors to Differentiate between Duke Cherry (Prunus x gondouinii (Poit. & Turpin)Rehd.) and Its Progenitors: Sweet Cherry (Prunus avium L.) and Sour Cherry (Prunus cerasus L.)
The rapid identification of the hybrids between sweet cherry (Prunus avium L.) and sour cherry (Prunus cerasus L.) is not easy. In order to resolve this problem, 18 Spanish sweet, sour and duke cherry cultivars were surveyed and characterized using 43 agromorphological descriptors evaluated in flowers, leaves, dormant 1-yr-old shoots, fruits, and trees during 2005 and 2006. Based on quantitative parameters, ANOVA and stepwise discriminant analysis (SDA) were carried out. For qualitative descriptors, statistical comparisons were done by means of the chi-square (χ2) test. As result of the study, two quantitative (titratable acidity and number of lenticels) and six qualitative descriptors (shape of the central and lateral lobes in the internal bracts of the flower fascicles, leaf shape and margin, pubescence in the veins of the lower side of the leaf, and type of sulci of the seed coat) were identified as differential parameters in P. avium, P. cerasus and P. x gondouinii(Poit. & Turpin) Rehd. Also, another four qualitative descriptors (petal coloration at the end of blooming, leaf stipule type, and seed shape and viability) were found to be useful for easy differentiation between sour and duke cherry. None of these parameters has been employed previously to discriminate among sweet, sour and duke cherry.