| Popis: |
The association of Infrared thermal imaging and specific target traits for drought tolerance (presence of awns,Normalized Difference Vegetative Index (NDVI), Relative Water Content (RWC), leaf area) with yield performanceunder three water regimes was analyzed utilizing wheat genotypes in two seasons (2012/2013 and 2013/2014). In thisstudy eight genotypes of bread wheat were used for screening them under three water regimes; control 100% FieldCapacity (FC), 75% FC and 50% FC. The presence of awns had a significant effect on yield loss under drought amongstwheat genotypes. Moreover, an infrared crop water stress index was calculated in the main water requirement stage.RWC was determined to give indication on the plant water status during the experiment. RWC ranged from 47.2% to76.5% for water stress (50% FC). NDVI ranged from 0.31 (Maser 2) to 0.49 (H2) under water stress 50% FC. Thisresult indicated that hybrid (H2) had the greatest green biomass and could be considered as a drought tolerant genotype.Temperatures of canopies can be used as indicators of stomatal closure in response to soil water deficit. It was foundthat thermal imaging can distinguish between stressed and non-stressed canopies, and even between deficit watertreatments. Leaf temperature (T leaf) varied between water stress treatments and among the wheat genotypes within thesame water treatment. Where, T leaf was ranged from 21.9 to 25.3°C for 50% FC treatment. Similar observations werenoticed for the other water treatments. Indicating that the other physiological mechanism could be influenced on thebehavior of genotypes due to water stress and subsequently leaf temperature was affected. Variation of the distributionof temperatures within canopies was found to be a reliable indicator of water stress. It could be concluded thatcombining thermal camera technology with physiological traits was sufficiently to predict wheat production underwater stress. |
