The Effect of Exogenous Application of Gibberellic Acid on Two Salt Stressed Paddy Cultivars during Seed Germination (original) (raw)

Agriculture is a major essential activity in many parts of the world. It provides adequate nutrition and also concerned with economic development especially in developing countries. In India nearly 70% of population directly or indirectly depends on agriculture and contributes almost 16.1% of G.D.P. Cereals are rich in vitamins, minerals, carbohydrates and protein. The starch mobilization of seed reserves and supply substrates essential for growth of the embryonic axis. Rice is a salt sensitive crop; NaCl inhibits mobilization of seed reserves. Gibberellic acid (GA 3) induces the synthesis of α-amylase in embryoless rice seeds. Salinity is the most brutal environmental factor limiting the productivity of crop plants. High salt concentration in soil or in irrigation water causes drastic effect on plant metabolism, and in turn disrupting cellular homeostasis and major physiological and biochemical processes. Mechanisms combining the molecular, physiological, biochemical and metabolic aspects of salt tolerance are essential to develop salt-tolerant crop varieties. Recently, some protectants viz; proline, glycinebetaine, trehalose, gibberellic acids, jasmonic acids, salicylic acid, ascorbic acid, glutathione, tocopherol, nitric oxide, hydrogen peroxide, spermidine, selenium, silicon, etc. have been found to be effective in mitigating the salt induced damage in plant and in turn enhance the plants growth, yield and stress tolerance under salinity. Gibberellic acids (Gibberellins A 3 , GA, and GA 3) are concerned with growth. In the present investigation, an attempt has been made to study paddy cultivars primed with GA 3 and challenge with different saline conditions. Seed germination and vigor index has been improved by the application of GA 3. The mean shoot, root and seedling length and also Chlorophyll content and mean protein content of Jaya and Tanu rice cultivars in control and different concentrations of GA 3 treated with NaCl showed significant difference. Biotic stresses form the greatest constraint for crop production worldwide; more than 50% of yield reduction was also due to abiotic stresses (Acquaah 2007). Our results are correlated with the studies of Kumar and Singh (1996). Root, shoot and seedling lengths were also increased upon GA 3 priming under salt stress conditions (Kim and Son 2006). Similarly, Amal et al., (2014) who also reported that, gibberellins treatment on wheat seedlings under salinity stress will increases the Chlorophyll content.