Morpho-physiological traits associated with terminal drought- stress tolerance in triticale and wheat
*Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan 84156 83111, Iran; e-mail: email@example.com
The objectives of this study were to evaluate the genotypic effects on tolerance to terminal drought stress in triticale and to compare it with that of durum and bread wheat under drought stress and normal field conditions using morpho-physiological traits. Five triticale ('Zoro', 'Moreno', 'Lasko', 'Prego' and 'Alamos 83'), one bread wheat ('Roshan') and one durum wheat ('Osta-Gata') cultivars were used. A randomized complete block design with three replications was used in each of the drought stress and well-watered (non-stress) experiments. Morpho-physiological traits including chlorophyll content, relative water content (RWC), excised leaf water retention (ELWR), rate of water loss (RWL), initial water content (IWC), leaf area, leaf angle, number of stomata, pollen viability, dry weight of awn and awn length were evaluated. Results of combined analyses of variances indicated the highly significant differences among genotypes for all traits and significant genotype × environmental interaction for all traits with the exception of leaf width, number of stomata and awn length. Overall performance of triticale cultivars was superior to wheat cultivars under both environmental conditions. Among triticale genotypes, 'Lasko' and 'Moreno' cultivars were the most drought tolerant and 'Prego' cultivar was the most sensitive genotype to water stress. Under drought stress conditions ELWR showed significant and negative correlation with grain yield, while their correlation was significant and positive under non-stress conditions. This relationship indicates that ELWR had an important impact on grain yield under both water stress and non-stress conditions.