Adaptation of Wheat (Triticum aestivum L) Genotypes and Related Species to Water Deficiency

Wheat production is limited primarily by water deficiency. The challenge of our days is to increase production with less water by promoting biological basis of drought tolerance and higher water use efficiency (WUE). Eight genotypes were examined to make comparison of their response to drought. The plants were grown in pots filled with 8.5 kg soil. The drought stress was started at the mid-flowering stage (Zadoks' scale: 65) and continued till maturity by adding only 50% of the water given to the control pots. Morphological and physiological characteristics known to be related to drought tolerance were examined. Duration of grain filling was shortened by 3 days in the mean of genotypes, the number of productive tillers were reduced by about 20% in case of the newly bred cultivars and 4-11% for extensive genotypes because of water deficiency. The highest root dry weight increment was measured in case of Emese (71%) and Pantlika (54%), while Cap.Des. increased it's root weight only by 24%. Yield reduction was found between 11- and 44% and was mainly due to decrease of thousand grain weight (TGW). Regarding netto photosynthetic activity, intensive cultivars had positive balance even in stress treatment, while the extensive genotypes reacted with quick closing of stomata. The genotypes with small yield decrease proved to improve their WUE to a grater extent. According to our results Pantlika and Emese proved to be drought tolerant cultivars.