Determination of drought tolerance of some exotic vegetable species

In this study, Mibuna (Brassica rapa var. nipposinica), Mizuna (Brassica rapa var. Japonica), Misome (Brassica campestris var narinosa), Komatsuna (Brassica rapa var. perviridis), Japanese mustard (Brassıca juncea L.), Chinese mustard (Brassica campestris var. chinensis), Coriander (Coriandrum sativum L.), Chives (Allium schoenoprasum), Basil (Ocimum basilicum), Molehiya (Corchorus capsularis and Corchorus olitoruus) were used as plant material. All experiments were performed, 25/20 °C temperature (day / night), 65-70% Rh (relative humiditiy) , 12/12 (light / dark) hour photoperiod, 400 µmol m-2s-1 in a climate room. Hoagland hydroponic solution was given by drip irrigation in hydroponic system during the emergence and seedling periods, and then water stress applications were launched. The experiment consists of 5 replications with randomized plots with 10 species (Mibuna, Mizuna, Misome, Komatsuna, Japanese mustard, Chinese mustard, Coriander, Chives, Basil and Molehiya) and 4 PEG6000 concentrations (Control, -4 MPa, -8 MPa ve -12 MPa). During the harvest period, some morphological, physiological and chemical measurements were made in plants. According to the obtained results from the trial, when the PEG6000 concentrations in the Hoagland hydroponic solution was increased, seedling root length, seedling stem diameter, number of leaves, weight of leaf, leaf thickness, leaf area, leaf fresh and dry weight, leaf water potential, chlorophyll amount in the leaves and amound of macro-micro nutriets decreased. Contrary to these results, the leaf damage index, membrane damage in leaf cells, leaf stoma permeability and leaf temperature values increased with the increasing rates of water stress. As a result; In places with drought problems, chives, Molehiya and Japanese mustard cultivation are recommended, which seem to be more drought-resistant than other species. Key Words: Japanese greens, PEG6000 concentration, water stress, leaf water potential