An analysis of physiological index of differences in drought tolerance of tomato rootstock seedlings

Drought is one of the most limiting factors for plant growth and development. In this study, experiments were carried out on five tomato rootstocks were subjected to water withdrawal and re-watering. Two RKN (root-knot nematodes)-and drought-dual resistant rootstocks were identified according to phenotype, physiological and molecular indexes such as the leaf relative water content (LRWC), electrolyte leakage (EL), water loss of the leaf, proline content, and increased activities of antioxidant enzymes, including peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and the transcript levels of drought stress marker genes. Further, we preliminarily investigated the mechanism underlying improved drought tolerance arising from grafting. These results will promote the application of these rootstocks in tomato production and provide new information on the mechanism of tomato grafting.