Evaluation of desirability index in selection of apple cultivars using adjusted ‎selection index of ideal genotypes (ASIIG)‎

In order to determine the desirability based on the qualitative and quantitative traits of the fruit, 11 cultivars of apple spore type along with control cultivar Golden Delicious were used. These cultivars were evaluated in Kamalshahr Horticultural Research Station of Karaj during two crop years (2011–2012) in a randomized complete blocks design with three replications and fruit related traits including fruit weight, fruit length, fruit diameter, fruit firmness, acidity percentage, TSS, fruit yield, fruit–set % and number of fruits per tree were recorded during two years. Combined analysis of variance showed that the effect of year was significant only for fruit diameter and fruit weight at the probability level of 5 % (P≤0.05). The effect of cultivar on all traits, except fruit–set %, was significant at the probability level of 1% (P≤0.01). The highest fruit yield was observed in Yellowspur cultivar with a value of 23.39 kg per tree. Using specific scores as the weight of traits, adjusted selection index of ideal genotype (ASIIG) was calculated and it was observed that Yellowspur cultivar with an index value of 78.16 % similar to the ideal genotype has the highest desirability among the cultivars and Yellowspur along with Golden Smoothie and Deliciousspur cultivars were more desirable than Golden Delicious cultivar. The graphs obtained from the adjusted selection index of ideal genotype with appropriate grouping of experimental cultivars identified only Yellow spur cultivar as a completely desirable cultivar.