Abstract
Four experiments were conducted at the plant Physiology laboratory and glasshouse Of the
Dept. of Crop Botany, Bangladesh Agricultural University, Mymensingh, along with one
field experiment under natural saline at Agricultural Research Station,
Bangladesh Agricultural Research Institute, Benerpota, Satkhira during 2015-16 and 2016-
17. Thirty five Sorghum germplasm were examined in the first to investigate the
salinity stress on germination using four concentrations (0, 6, 12 and 18 dSm•1) in complete
randomized design with three replications. The second was designed as
factorial using 18 selected %rghum germplasm (16 tolerant and 2 susceptible) from
previous germination experiment to test their morpho-physiological and biochemical
attributes against salinity in hydroponics under control (0 dSm-1) and saline (12 dSm-1)
condition. The third experiment was laid out in a factorial design with three replications
using the 1() Sorghum germplasm (8 tolerant and 2 susceptible) selected from previous
experiment under control and saline (12 dSm-1) conditions to observe the bio-chemical and
physiological mechanisms for salt tolerance in %rghum at stage. In
four, 10 Sorghum germplasm were tested to identify suitable germplasm in
terms of growth, yield components and yield under natural saline soils in costal belt of
Bangladesh. The experiment was laid out in Randomized Complete Block Design with three
replications during the Rabi season of 2016-2017. Germination stress tolerance index (GSI)
of 35 germplasm under the study ranged from 21.81-98.84, 7.51-65.78 and 0-30.66 at 6, 12
and 18 dSm-1 respectively. Among those, 18 germplasm were selected for hydroponics
study based on the GSI value under 6 and 12 dSm-1 salinity concentrations. Index of leaf
growth, leaf number, root shoot ratio, shoot fresh weight, shoot dry weight, root fresh
weight, root dry weight of the tested Sorghum germplasm in hydroponic culture also
differed significantly. Root, shoot dry and fresh weight, Na• and K* content in plant parts
varied significantly. Based on the relative value of different studied parameters and using
modified SFS score, 8 tolerant and 2 susceptible germplasm were selected and subjected to
pot trial under induced salinity. Morpho-physiological and biochemical characters of the
Sorghum germplasm varied significantly under imposed salinity condition in pot culture.
Plant height at different dates, SPAD, root length, root, shoot and total dry weight, days to
panicle initiation, proline content at vegetative and reproductive stages were measured.
Root and stem content showed sharp increase due to salinity stress. Total Nay and
found significantly higher in the susceptible germlasm. In all respect, Hybrid
%rgo, %rghum BD-701, BD-730, %rghurn BD-731, Sorghum BD-733 and
%rghum BD-737 performed better among the tested germplasm in pot culture. The Same
set of the germplasm were taken for field trial under natural saline soils. Sorghum
germplasm significantly varied in all characters investigated except number of leaves plant-
I at 30, 60, and 90 days and number of tillers plant-I at 60 days after sowing. The Na• content
of rcx't, stem and leaves differed significantly among different germplasm at different days
after sowing. The K*-Na+ ratio changed significantly among the %rghum germplasm tested
at 60 days after sowing. The highest K*-Na• ratio was calculated from the germplasm
Sorghum BD-737. The germplasm Sorghum BD-737 recorded the highest grain yield
followed by Hybrid Sorgo. Based on the results, BD-737, Hybrid Sorgo, Sorghum
BD-701, and Sorghum BD-730 can be recommended for further field trial in different coastal
regions of Bangladesh.