Influence of Strigolactone (GR24) as a Seed Treatment on Growth, Gas Exchange and Chlorophyll Fluorescence of Wheat under Saline Conditions

Striglactones are generally considered as the signaling molecules. A pot experiment was conducted to explore the role of strigolactone (GR24) as seed treatment on wheat under saline conditions. Seeds of two wheat cultivars (S-24 and PARI-73) were sown in sand. Two salt treatments [control (non-saline) and 150 mM (NaCl)] nourished with full strength Hoagland's nutrient solution were applied as root growing medium while four strigolactone (GR24) levels (water (0), 0.001, 0.01 and 0.1 mg L-1) were applied as seed treatment for 16 h. Imposition of salt stress significantly reduced growth attributes while plants developed from seeds raised with GR24 showed variable response on growth under salt stress. Pre-sowing seed treatment with GR24 showed non-significant effect on shoot fresh and dry weight and root length. Net CO2 assimilation rate of both wheat genotypes increased due to GR24 application. In chlorophyll fluorescence plants showed increasing response towards application of GR24 with respect to co-efficient of photochemical quenching (qN) and non-photochemical quenching (NPQ) under non-saline. Root-medium salinity significantly enhanced the concentrations of Na+ ions and decreased K+ ions in shoot and roots. Pre-seed treatment with GR24 did not modulate concentration of shoot and roots Na+ and K+ ions. Overall, the wheat cultivar S-24 showed better performance for growth parameters and non-significant behavior towards the photosynthetic rate. Both the cultivars showed uniform response in chlorophyll fluorescence. (C) 2017 Friends Science Publishers