Drought is a serious threat of wheat seed germination, growth and productivity in Bangladesh. A germination test was set to examine the influence of seed priming with various agents on seed germination and early seedling growth in two wheat cultivars (BARI Gom 28 and BARI Gom 29) under control and drought conditions. The experiment was conducted following completely randomized design with three replications. Four priming treatments were used such as i) hydropriming (distilled water, control), ii) 10% Polyethylene Glycol (PEG-6000), iii) 100 mM CaCl2 and iv) 1 mM ascorbic acid (AA). The primed seeds of two wheat cultivars were set in petri dishes for germination under two growth conditions viz. i) control and ii) drought (10% PEG-6000). In both cultivars and growth conditions, all priming agents increased final germination percentage (FGP), root and shoot length and root and shoot biomass in comparison to control. All these parameters were significantly affected by drought stress in both wheat cultivars. The highest FGP was observed in AA and CaCl2 priming (73%) in both cultivars under drought stress compared to the others. The root length and root dry weight were also higher in AA and CaCl2 priming in both cultivars and growth conditions but the variations between AA and CaCl2 were statistically similar. All seed priming techniques increased the stress tolerance indices and root-shoot ratio in both wheat cultivars showing an increased tolerance to drought. The higher values of stress tolerance indices in BARI Gom 28 compared to BARI Gom 29 indicated that the cultivar BARI Gom 28 performed better in response to drought and priming agents. In conclusion, the priming agents AA and/or CaCl2 (depending on availability and cost effectiveness) could be used for improving seed germination and early seedling growth both under control and drought stress conditions.
Key words: Wheat, seed priming, drought tolerance, germination, seedling growth
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