Akademik Veri Yönetim Sistemi
6th Balkan Symposium on Vegetables and Potatoes, Zagreb, Hırvatistan, 29 Eylül - 02 Ekim 2014, cilt.1142, ss.369-375
The study was conducted to determine tolerance levels of two tolerant (T-1: TR-68516 and T-2: 'Rio Grande'), and two sensitive (S-1: TR-63233 and S-2: H-2274) tomato genotypes to drought. Three different irrigation treatments have been applied (Do: control: when 40% available water is consumed, D-1: when 90% available water is consumed, D-2: no water was given when plants reached 3-4 leaves stage). The drought stress index, malondialdehyde (MDA) content, antioxidant enzyme activities and ions contents (Ca, Zn, Mn, and Fe) were investigated. Visual injury assessment was conducted according to a 0-5 scale created for this purpose. According to that the most affected genotypes were S-1 and S-2 respectively. Irrigation treatments D-1 and D-2 caused reduction in the leaves K, Ca, Zn, Mn and Fe contents compared to the control. In the salt-tolerant cultivars, the decrease of ions contents was less under drought conditions. SOD, CAT, GR and APX enzyme activities have increased in drought stress conditions. The four genotypes showed an increase in MDA content under drought conditions, especially in the sensitive genotypes. As a result, visual scaling was noted to be an important parameter for determining tolerance of plants under drought stress. Plant ions regulation especially K and Ca, and enzymatic defense system seem to be effective against drought stress in tomato.