Evaluation of phlorizin stress resistance and mineral nutrient utilization efficiency in apple seedlings with different dwarfing interstocks

• The nutrient utilization efficiency of new interstocks were studied in apple cv Tianhong 2. • Apple dwarfing interstocks varied in their responses to phlorizin stress. • J1 had the strongest phlorizin tolerance and nutrient utilization efficiency, followed by SH40 and J2. Excessive accumulation of phlorizin in soil is one of the main causes of apple replanting disease (ARD). This study evaluated the effects of phlorizin stress on apple seedlings grafted with three dwarfing interstocks [Jizhen 1 (J1), Jizhen 2 (J2), and SH40]. Phlorizin stress increased relative electrolyte leakage, caused reactive oxygen species and malondialdehyde accumulation, and significantly reduced chlorophyll content, photosynthesis rates, and nutrient absorption, accumulation, and transport, inhibiting apple tree growth regardless of the interstock. Antioxidant enzyme activity was significantly affected in each rootstock/interstock/scion combination under phlorizin stress; however, apple seedlings maintained higher antioxidant enzyme activity levels when J1 was used as the interstock. Principal component and membership function analyses showed that compared to the other interstocks, J1 conferred stronger resistance and mineral nutrient utilization efficiency for apple trees to cope with phlorizin stress. These results highlight the phlorizin resistance and nutrient utilization efficiency of different interstocks under phlorizin stress and provide new insights into the breeding of ARD-resistant rootstock.