Grain yield, chlorophyll content, osmolyte accumulation, total phenolics and catalase activity in maize (Zea mays L.) under drought stress

To study the response of grain yield, chlorophyll (a) content, glycine betaine, proline, soluble sugars, total phenolics, and catalase (CAT) activity in maize hybrids to drought stress during kernel filling stage, a field experiment was carried out as a split plot completely randomized block design with four replications in Moghan Research Station, during 2010 and 2011 growing seasons. The main plots were composed of two drought stress levels including commonly available irrigation water (control) and no irrigation at kernel filling stage. Three maize hybrids including NS640, SC704, and SC720 were allocated into sub-plots. Analysis of the data suggested that drought stress significantly affected all measured characters and reduced grain yield (30.7%) and chlorophyll (a) content (14.7%). Drought stress also increased glycine betaine, proline, soluble sugars, total phenolics, and CAT activity about 30.2, 36.7, 17.8, 38.8 and %15.2, respectively. SC704 displayed maximum grain yield and osmolyte accumulation. Based on the findings of the study, grain yield, chlorophyll (a) content, glycine betaine, proline, soluble sugars, total phenolics, and catalase (CAT) activity can be used to study drought-response and drought-tolerance of maize hybrids.