Role of grafting in vegetable crops grown under saline conditions

Salinity is one of the major abiotic stresses that reduce plant growth and crop productivity in many vegetable production areas of the world. Grafting can represent an interesting tool to avoid or reduce yield losses caused by salinity stress in high-yielding genotypes belonging to Solanaceae and Cucurbitaceae families. Grafting is an integrative reciprocal process and, therefore, both scion and rootstock can influence salt tolerance of grafted plants. Grafted plants grown under saline conditions often exhibited better growth and yield, higher photosynthesis and leaf water content, greater root-to-shoot ratio, higher accumulation of compatible osmolytes, abscisic acid and polyamines in leaves, greater antioxidant capacity in leaves, and lower accumulation of Na+ and/or Cl− in shoots than ungrafted or self-grafted plants. This report gives an overview of the recent literature on the salinity response of grafted plants and the mechanisms of salt tolerance in grafted plants related to the morphological root characteristics and the physiological and biochemical processes. The review will conclude by identifying several prospects for future researches aiming to improve the role of grafting in vegetable crops grown under saline conditions.

Research highlights▶ Salinity in soil or water is one of the major abiotic stresses that reduce plant growth and crop productivity worldwide. Most of the vegetable crops are glycophytes and, therefore, highly susceptible to soil salinity even at low electrical conductivity in the saturated soil extract. ▶ One environment-friendly technique for avoiding or reducing losses in production caused by salinity in high-yielding genotypes belonging to Solanaceae and Cucurbitaceae families would be to graft them onto rootstocks capable of ameliorating salt-induced damage to the shoot. ▶ The aim of this paper is to review the recent literature on the salinity response of grafted plants and the mechanisms of salt tolerance in grafted plants related to the morphological root characteristics and the physiological and biochemical processes. The review will conclude by identifying several prospects for future researches aiming to improve the role of grafting in vegetable crops grown under saline conditions.