Abstract:
Objective The paper aims to investigate the effects of exogenous melatonin on the growth and selenium accumulation of grape, and screen out the optimal melatonin concentration that could promote grape growth and selenium (Se) accumulation.
Methods The cuttings of 'Xiahei' grape was used as the material, and the pot experiment was conducted to study the effects of melatonin on the growth, physiology and Se accumulation of grape seedlings under Se stress.
Results Different concentrations of melatonin increased the biomass and root/shoot ratio of grape seedlings to a certain extent, and melatonin with a concentration of 150 μmol L−1 had the greatest increase (18.22%) in the shoot biomass of grape seedlings. Melatonin treatment also increased the contents of chlorophyll and carotenoids in grape seedlings to a certain extent, improved the photosynthetic capacity and antioxidant enzyme activities, and decreased the proline content, soluble protein content, relative conductivity, and malondialdehyde content. Different concentrations of melatonin increased the Se content in grape seedlings, among which melatonin at a concentration of 150 μmol L−1 increased the Se content in the shoots of grape seedlings the most (112.71%). Regression analysis showed that there were quadratic polynomial or linear regression relationships between melatonin concentration and root biomass, shoot biomass, Se content in roots, or Se content in shoots of grape seedlings.
Conclusion Exogenous melatonin can promote the grape growth and Se accumulation under Se stress, and the concentration of 150 μmol L−1 is the best.
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