Abstract:
The experiment was conducted at The Central Laboratory of Sher-e-Bangla
Agricultural University (SAU), Sher-e-Bangla Nagar, Dhaka-1207 during the period
from August to November 2016. Two experiments were conducted to study the
mannitol induced salt tolerant capacity of wheat under salt stress condition. The
experiment was laid out in a Completely Randomized Design (CRD) with five
replications. Three wheat genotypes viz. V
1
(BARI Gom-28), V
2
(ESWYT-5) and V
(ESWYT-6) were used as test crop. Mannitol was used as priming chemicals and salt
(NaCl) were used for salinity stress. Alcohol was used as surface sterilizer of wheat
seeds. The data were recorded on germination percentage, root length, shoot length,
root dry weight and shoot dry weight, fresh weight, turgid weight, relative water
content, water retention capacity and vigour index. Data were analyzed using a
computer software MSTAT-C. For the first experiment four levels of mannitol such
as 2%, 4%, 6% and 8% were used for osmopriming and water was used for
hydropriming. Among the genotypes, V
(ESWYT-5) gave the best results on
studied parameters. Results revealed that the V
2
showed the highest germination rate
(96.67%), shoot length (148.40 mm), root length (109.95 mm), shoot dry weight
(9.65 mg), root dry weight (6.42 mg), fresh weight (264.55 mg), turgid weight
(282.65 mg), relative water content (93.21%) and vigour index (43.04) primed with
2% mannitol solution for 9 hours where seeds without priming showed lowest results
in respected parameters with the genotype V
2
(BARI Gom-28). In the second
experiment, 2% mannitol primed (9 hours) seeds of wheat genotypes above
mentioned with and without salt (NaCl) stress condition was evaluated. The salt
stress levels (0 dS/m), 5dS/m, 10 dS/m, 15 dS/m and 20 dS/m were used during
experimentation. It was observed that the genotype V
1
(ESWYT-5) with primed
seeds placed without salt; (control) gave the best performance on respected
parameters but under salinity stress, the highest germination rate (93.33%), shoot
length (142.85 mm), root length (115.20 mm), shoot dry weight (11.66 mg) and root
dry weight (8.01 mg), fresh weight (215.65 mg), turgid weight (268.55 mg), relative
water content (88.03%) and vigour index (238.9) were achieved from V
2
primed
seeds placed with 5 dS/m NaCl where V
primed seeds placed with 20 dS/m NaCl
showed lowest results in respected parameters. Priming with water was more
effective than control with regard to enhanced germination and growth parameters.
From the result of the study, it was observed that seeds primed 2% mannitol for 9
hours showed the best result to compare with water primed and non-primed seed
under salt stress condition.