Effect of drought on morphological and physiological development of bread wheat (Triticum aestivum l.) genotypes at pre and post heading period

The goal of the study was to determine the effect of drought on the bread wheat genotypes at pre-and post-heading stage. This research was conducted for two years in 2017-2018 and 2018-2019 wheat growing season at Dicle University Faculty of Agriculture Research and Application Field in Diyarbakir, Turkey. Two check varieties (Empire and Pehlivan) and 8 CIMMYT bread wheat lines were used as materials in the study. Significant differences in all features such as heading stage, chlorophyll content (SPAD), normalized difference vegatation index (NDVI), leaf area index (LAI), plant height, grain weight and grain yield between the genotypes were identified. Based on the results of the correlation analysis performed over the two-year average data; grain yield was found to be correlated with an increase of all the characteristics studied during the pre-heading period when drought stress were encountered. In terms of grain yield, late varieties are resistant to stress that occurs prior to heading, while early varieties have become advantageous after heading. According to the results of the study, ideal genotypes with high yield and stability are expected to have moderate heading stage in environments where precipitation fluctuates from year to year due to climate change.