Abstract
Many inbred lines of maize are unable to synthesize glycinebetaine (GB). The present study was conducted to assess the influence of exogenously applied GB on growth and photosynthetic attributes of maize (Zea mays L.). Two maize varieties were C-20 and C-77 (C stands for Comb). Exogenously applied different levels i.e. control (without spray), water spray, 50 or 100 mmol L" of glycinebetaine had no increasing or decreasing effect on shoot length, shoot fresh and dry weights. Among different gas exchange attributes only stomatal conductance (gs) and transpiration rate (E) increased while photosynthetic rate (A), sub-stomatal CO2 cone. (Gj) and water use efficiency (WUE) were unaffected by foliar spray of GB. Chlorophyll a was high at 100 mM of GB for C-20, whereas in case of C-77 water spray gave maximum value. There was no effect of GB on chlorophyll b. Key words: Glycinebetaine, maize, photosynthetic attributes
