Blue Mold Resistance Association with Pomological Traits in Local and Commercial Peach and Nectarine Cultivars

Penicillium expansum Link. is a major decay agent of fruits including peach and nectarine، in storage. In this research، relative resistance of fourteen commercial and local peach and nectarine cultivars to blue mold in cold storage and its correlation with physicochemical traits as potential resistance indicators were studied. For inoculation، the fungus conidial suspension was prepared and inoculated in wells in equatorial region of fruit. The fruits were then transferred to a cold storage room and lesions diameter was measured six weeks later. Pomological traits including cortex firmness، epidermal toughness، total soluble solids، titratable acidity and total acidity were also measured and their correlation with lesion diameter was studied. Based on the results، different susceptibility levels were observed in cultivars and mean lesion diameter varied from 3. 31 cm in Shams cultivar to 0. 58 cm in Sunglu cultivar. Clustering based on lesion diameter indicated that Shams was highly susceptible، Anjiri، MHF101، Independence، Rome Star، MHF100، MHF102، Nectared 9 and Nectared 4 were susceptible and GH Hall، Red Skin، Sunglu and Nectared 6 were relatively resistant. All cultivars varied in physicochemical traits. A negative correlation was observed between lesion diameter and titratable acidity and epidermal toughness but these relations were not strong enough to be used as decay resistance criteria.