抄録
To analyze the extent of variations in salt tolerance in soybean, 170 genotypes were screened against salinity stress at the vegetative stage at the Department of Agronomy of Bangabandhu Sheikh Mujubur Rahman Agricultural University in Bangladesh. The plants were grown in pots, subjected to saline irrigation of 150 mM NaCl solution, from 14 to 30 days after sowing; then plant height and dry weight of different plant parts were measured. The genotypes showed a wide variation in different plant characters. Relative plant height (percent value to the control) ranged from 43.2 % to 98.3 % with a mean of 73.0 %, the relative stem dry weight from 24.7 % to 99.4 % with a mean of 59.4 %, the relative leaf dry weight ranged from 6.9 % to 98.7 % with an average value of 48.9 % and the relative root dry weight from 9.8 % to 96.4 % with a mean of 65.3 %. Similarly, the relative shoot dry weight (RSDW), which is the sum of the dry weight of stem, leaf and petiole, ranged from 20.4 % to 93 % with an average value of 52.2%. The genotypes were grouped into different salt-tolerance categories based on their RSDW value and salinity susceptibility index (SSI). Among the 170 genotypes, 13 which showed a low SSI (0.265) and high RSDW (> 80 % of the control) under salinity were grouped into tolerant category, 36 into the medium-tolerant category with a SSI of 0.666 and RSDW in the range of 60-80 %, while 83 genotypes were medium-susceptible with a SSI of 1.052 and 40-60% RSDW, and the remaining 38 genotypes were grouped into the susceptible category with a SSI of 1.376 and <40% RSDW. The wide genotypic variations in salinity tolerance might be useful for improving the salinity tolerance level of this crop through genetic manipulation programs.
