Grafting in Vegetable Crops for Combating Biotic and Abiotic Stresses and Enhancing Productivity: A Critical Review

Abstract

Vegetable production is increasingly constrained by soil-borne pathogens, nematodes, salinity, drought, temperature extremes, waterlogging and heavy-metal contamination, all of which threaten yield stability and produce quality. Grafting, the union of a commercial scion with a stress-tolerant or disease-resistant rootstock, offers a practical approach for strengthening vegetable crop performance without altering the market-preferred shoot genotype. This review critically synthesises the physiological, molecular and agronomic evidence on grafting in major solanaceous and cucurbitaceous vegetables. It examines graft union formation as a coordinated process involving wound signalling, callus proliferation, vascular reconnection and long-distance rootstock–scion communication. The review further evaluates how rootstocks influence ion transport, water relations, hormonal balance, antioxidant responses, nutrient acquisition and rhizosphere microbial assembly under biotic and abiotic stresses. Evidence is assessed for the use of grafting against Fusarium wilts, bacterial wilt, root-knot nematodes, salinity, drought, heat, chilling, waterlogging and cadmium stress, alongside its effects on nutrient-use efficiency, yield stability and fruit quality. The synthesis indicates that grafting is most reliable where clearly defined stress pressure exists, particularly from soil-borne diseases or adverse root-zone conditions. However, responses remain strongly dependent on crop species, production environment and rootstock–scion compatibility. The review therefore emphasises targeted rootstock selection, standardised compatibility screening and multi-stress field validation as priorities for improving the predictability of grafting in sustainable vegetable production.