Effect of water deficit on growth and photosynthetic characteristics of 13 winter wheat
Wheat is one of the major crops in the world and is rather sensitive to water deficit and differences between genotypes for water tolerance have been previously testified. Experiment was conducted in a greenhouse with 13 cultivars grown in control and water deficit conditions. Gas exchange, chlorophyll fluorescence parameters, above ground biomass and total leaf area were measured to determine water tolerance. Drought susceptibility indexes were used to estimate the relative tolerance of wheat cultivars to water deficit. Water deficit decreased total leaf area, above-ground biomass, net photosynthesis, stomatal conductance, internal CO2 concentration and the actual quantum yield of PS II electron transport relative to cultivars that were grown under control condition. Measurement of stomatal conductance provided useful information to assess genetic differences in wheat for absolute performance when subjected to water deficit. Besides, CY20 and XN979 showed more drought tolerance than other wheat cultivars in terms of drought susceptibility indexes.
Key words: Wheat cultivars, growth, chlorophyll fluorescence, gas exchange, water deficit.