Changes of Nitrate and Carbonate Contents in Leaves of Tomato ( Lycopersicon pnennellii) by Salt Stress.
Byoung Choon Jang, National Institute of Agricultural Science and Technology, RDA, Seodun-Dong 249, Gwonseon-Gu, Suwon-Shi, 441-707, South Korea
Salt stress and water deficit are perhaps the two most important soil stresses that limit plant growth and development. To cope with them, plants must be able to sense and respond to them rapidly. The purpose of this study was to investigate changing nitrate and carbonate contents in plants under high salinity conditions. Three races of tomatoes (Lycopersicon pnennellii) were used (B-baia, Sweet, and CoCo) and grown in beds which were filled with perlite:peatmoss (1:1). Nutrient solution was given 2 times for 30 minutes every day. The nutrient solution were Hanbang A, B (CoSil Co. Ltd) and added NaCl or CaCl2(2:1 W/W) to control EC Levels(2, 3, 5, 9, 17 ,25 dS/m). We analyzed nitrate, sucrose, starch, proline and mineral contents in upper leaves (1-4th from top) and middle leaves (5-19th from top) of tomato. Evaluation of growth rates of tomatoes at various EC levels (2, 3, 5, 9, 17, 25 dS/m) showed growth rate inhibition as EC levels increased. Inhibition was observed for all races evaluated(B-baia, Sweet, CoCo). Proline contents increased with increasing EC level from 2 to 25 dS/m. Proline contents at upper leaf were higher than at middle leaf. Also, proline increases were greater for upper leaves than for middle leaves. Nitrate contents of upper leaves were lower than nitrate contents of middle leaves under low level of EC (2, 3, 5, 9 dS/m), but there was no significant difference between upper leaf and middle leaf under high level of EC (17, 23 dS/m). Carbonate content of tomato leaves were decreased from 9ds/m EC level. Nitrogen contents were slightly decreased by increasing EC level. Also, Iron level was increased by increasing EC level.