A Comprehensive Review on the Role of Rootstocks in Fruit Crops: Effects on Fruit Quality, Bearing Behavior, and Scion-Rootstock Interactions

Rootstocks are central to modern fruit production, strongly influencing tree vigor, yield, fruit quality, and stress resilience. Through grafting, elite scion cultivars are combined with rootstocks that regulate water and nutrient uptake, hormonal balance, and responses to environmental stress. This review compiles current knowledge on rootstock classification and their functional roles in major fruit crops, emphasizing effects on vegetative growth, precocity, yield efficiency, and orchard lifespan. Contributions to fruit quality size, soluble solids, acidity, color, texture, and nutritional content are highlighted. Physiological and biochemical interactions between scion and rootstock, including water-mineral-hormone signaling and long-distance molecular communication, are discussed. The capacity of rootstocks to mitigate abiotic (drought, salinity, temperature) and biotic (pathogens, nematodes) stresses, as well as graft compatibility and orchard longevity, is examined. Future trends in marker-assisted selection, omics technologies, and precision horticulture are outlined to promote sustainable, high-quality fruit production.