GENOTYPIC DIFFERENCES BETWEEN TWO MUNGBEAN VARIETIES IN RESPONSE TO SALT STRESS AT SEEDLING STAGE

In order to study performance of mungbean to salinity stress, a laboratory experiment was carried out to investigate salinity tolerance of two mungbean varieties (Kawmy-1 and IV 2010) to eight salinity levels i.e. 0, 2, 4, 6, 8, 10, 12 and 14 dS/m of NaCl concen- trations. Mungbean (Vigna radiata (L.) Wilczek) varieties were compared for germination efficiency and seedling characters. Results indi- cated that mungbean IV 2010 variety recorded the highest percentages of final germination, germination index %, seedling vigor index, energy of germination, mean germination time (day), coefficient velocity, abnormal seed percentage, root and shoot length, root fresh and dry weight and seedling height reduction. Whilst, mungbean Kawmy-1 variety recorded the highest weight of fresh and dry shoot and relative dry weight. Highest germination parameters and seedling characters of the two studied varieties under control treatment. The obtained results suggested that the two varieties registered a decrease in the percentage of germination and seedlings growth at higher NaCl concentrations. Results clearly indicated that mungbean Kawme-1 variety appeared to be more tolerant to salt stress than IV 2010 variety recording higher germination parameters and seedling characters. Increasing salinity concentrations significantly reduced germi- nation percentage, seedling vigor index, coefficient of velocity, mean germination time, shoot and root length, shoot and root fresh and dry weight. It could be concluded that germination efficiency i.e. final germination percentage, germination index, energy of germination, mean germination time, abnormal seed percentage, root and shoot length, seedling total fresh and dry weight, dry weight reduction and shoot length reduction were gradually decreased significantly when salinity increased.