مرکز منطقه ای اطلاع رساني علوم و فناوري - Identification of Ion Accumulation and Distribution Mechanisms in Watermelon Seedlings (Citrullus lanatus (Thunb.) Mansf.) Grown under Salt Stress

Abstract :

The aim of this study was to determine ion accumulation and distribution mechanisms in watermelon. Salt sensitive Golden crown F1 and salt tolerant Midyat genotype Watermelon (Citrullus lanatus (Thunb.) Mansf.) seedlings were grown in Hoagland nutrient solution. When plants had 3-4 true leaves, 100 mM NaCl was applied. Shoot fresh weights, Na^+, K^+, Ca^+2 ion distribution in root, stem and leaves of the plants subjected to 14 days salt stress were determined. Salt tolerant Midyat genotype had higher shoot fresh weight than salt sensitive Golden crown F1 variety. Ion (Na^+, K^+, Ca^+2) accumulation in Golden crown F1 variety root was higher than Midyat genotype. Nevertheless, while Na ion accumulation in the shoot of the Golden Crown F1cultivars were higher, no differences between genotypes were determined for K^+, Ca^+2 ions. Na was higher in salt sensitive variety’s leaves, whereas, K^+ and Ca^+2 ions accumulation was higher in Midyat genotype’s leaves. As a result, it was determined in this study that salt avoidance mechanism worked in watermelon. Additionally, it was observed that watermelon acted to be selective in ion uptake, there was a competition in terms of K^+ and Na^+ ions uptake and this salt-tolerant genotype had higher K^+ accumulation rate. There was an increase in K accumulation in salt stress treated plants. A reverse relationship between K and Na ions was determined in ion distribution among organs. While N accumulation in an organ increased K ion accumulation decreased in that organ, and vice versa. Accumulation of Ca ions increased from root of the plant towards to leaves.