In order to better understand the critical period and the cellular changes accompaniment chilling injury in peaches, two peaches cultivars were analysed: 'Aurora-1' (chilling non-sensitivy) and 'Dourado-2' (chilling sensitivy) during storage at 3 °C followed by two days at 25 °C (simulated commercialization). Analysis on light and electron microscope were performed. Mesocarp tissue and cell anatomy from freshly harvest peaches were similar and presented turgid isodiametric parenchyma cells with different sizes and conspicuous intercellular spaces. The fruit mesocarp from both cultivars were similar and almost unchanged during storage at 3 °C for 7, 14, 21, 28 e 35 days. But, 'Dourado-2' fruits when transfered to 25 °C for two days after cold storage at 3 °C, showed typical mealiness symptoms like cell walls separation leading to increased intercellular spaces and accumulation of pectic substances in the intercellular matrix. Nuclear fragmentation and macroendocytosis process by endosome individualization were described by the first time as related to chilling injury.
anatomy; cold storage; fruits; Prunus persica; ultrastructure
