Turkish Journal of Agriculture - Food Science and Technology, cilt.8, ss.960-964, 2020 (Diğer Kurumların Hakemli Dergileri)
The aim of this study was to investigate the effects of exogenous Melatonin (100, 300 and 500 µM)
and L-tryptophan (125, 250, 375 ppm) applications on some growth parameters of lettuce plants
grown under salt stress. The study was carried out under semi-controlled greenhouse conditions in
spring (March/April) season. The exogenous applications to lettuce plants were carried out two times
as foliar spraying. Salt stress was generated by adding NaCl (0 mM, 100 mM, 200 mM) to irrigation
water. The complete randomized design was used with three replications in this experiment. At the
end of the study, it was found that the highest doses of exogenous applications had the highest effect
on the parameters of the number of leaves, salinity necrosis, fresh leaf weight, fresh root weight, and
total surface area of lettuce plants under 200 mM salinity condition. When the effects of the subtract
on these values were compared, the effect of melatonin was found to be more pronounced. Leaf
width, leaf length, and leaf surface temperature values were not affected by the external application.
These values only changed depending on salt concentration. As a result of the study, it was concluded
that the application of 500 µM melatonin significantly increased salt tolerance in lettuce plants.
However, in order to reach a more general conclusion, the dose ranges and genotype/variety numbers
should be increased.