Effects of melatonin on salt stressed garlic plants: Time-dependent monitoring of leaf morphology in early plant phase

Abstract

In this study, the effects of melatonin to garlic were investigated under salinity stress in the early plant growth phase. The experiment was carried out under semi-controlled greenhouse conditions in the spring season. Garlic cloves were soaked in solutions of different concentrations of melatonin (0, 1, 2, 4, and 8 mM) during a 12-hour period at room temperature and dark conditions. Salt stress was generated by adding NaCl (0, 100, 200, and 400 mM) to irrigation water. The complete randomized design was used with three replications. At the end of the study, it was found that the 2 mM Melatonin treatment had the highest effect on the leaf length under 400 mM salinity. In the same stress condition, the maximum leaf amount was obtained in 4 mM MEL treated plants. When the time-dependent change in the leaf length was examined, it was observed that there was a separation between MEL applications from the first week in high salinity environment. Leaf waxiness, leaf erect, and leaf color intensity values were not affected by the Melatonin applications. It was concluded that application of 2 mM and 4 mM melatonin significantly increased salt tolerance of garlic plants in the early plant growth phase.