SCREENING OF SALT TOLERANT EXISTING MUNGBEAN GENOTYPES IN BANGLADESH AND IMPROVEMENT OF SALT TOLERANCE THROUGH NUTRITIONAL MANAGEMENT

Abstract

Two pot experiments were carried out at Agronomy laboratory, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur during March 2014 to May 2015 to find out the response of mungbean genotypes on salinity and to alleviate salinity through nutrient management. For screening 11 mungbean genotypes (BARI mung 2, BARI mung 3, BARI mung 4, BARI mung 5, BARI mung 6, BINA mung 1, BINA mung 2, BINA mung 5, BINA mung 6, BINA mung 7 and BINA mung 8 were tested in three salinity levels (0, 75 and 125 mM) for 8 days in sand culture in plastic pot and another three salinity levels (0, 50 and 100 mM) were test for 30 days in small plastic pot. The germination of all mungbean genotypes was delayed and percentage was reduced with increasing level of salinity compared to control. Speed of germination as expressed by germination percentage (GP), germination index (GI) and vigor index (VI). BINA mung 8 showed better performances in terms shoot and root growth (fresh and dry weights), lower reduction of germination percentage (GP), germination index (GI) and vigor index (VI). On the other hand BARI mung 2 suppresed greatly in terms of fresh and dry weight, higher reduction of shoot and root lengths by the saline environment. Shoot growth was more affected than root. Results on germination and seedling growth indicate that BINA mung 8 was more tolerant and BARI mung 2 was more sensitive genotypes. BINA mung 8 was also used for alleviation of salinity through potassium nitrate (KNO3) application at five different levels (Control, 50 mM salt, 50 mM salt+10 mM KNO3, 50 mM salt+20 mM KNO3 and 50 mM salt+30 mM KNO3). Most of the growth and physiological characters viz., plant height, branches plant-1 , fresh and dry weight of leaf, stem, root and yield, yield contributing characters (number of pods plant-1 , number of seeds pod-1 , total seed weight plant-1 ) and root exudation rate performed better at 50 mM salt+30 mM KNO3 level and showed the lowest performance in respect of all the standared parameters at 50 mM saline condition. Therefore, BINA mung 8 should be cultivated at 50 mM saline soil by the application of 30 mM KNO3 at three growth stage viz., pre flowering, flowering and pod formation stage.