Response to salinity of two flue-cured tobacco varieties
1987
Agtarap, M.L.
It appears from this study that plants stressed with saline solution developed morphological and physiological adaptations (succulence, decrease transpiration) which enabled them to adopt to the stressed condition. The analyses of the organic and inorganic constituents further revealed the possibility of osmoregulation as the physiological basis for this adaptation. Ions which accumulate under salt stress include Cl-, Na+, K+ and to some extent Ca++. There is likewise a significant increase in the proline content of the stressed plants. All these were considered as possibly responsible for the decrease in the solute potential of the vacuole and cytoplasm, respectively, which consequently brought about the decrease of its water potential, thus allowing the flow of water from the soil to the plant. Accompanying these changes is the general decrease in the starch and sugar content of the tissues which is interpreted as possible sources of energy for accumulation against concentration gradient, compartmentation of the salts and as source of carbon for synthesis of other organic compounds. Cured tobacco leaves obtained from salt stressed plants and classified as salty were not directly correlated with chloride content. These leaves might have been caused by NH4+-Cl- toxicity. Chemical analysis shows that these types of leaves have low nicotine and reducing sugar content.
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