Robust wheat for the future

TY - GEN

T1 - Robust wheat for the future

AU - Abdelhakim, Lamis

PY - 2022/1

Y1 - 2022/1

N2 - Climate change already has an impact on agricultural productivity and food security. The continuously rising CO2 concentration contributes to global warming. Wheat is one of the global cereal crops that is highly in demand but is threatened by warmer and drier weather patterns that lower the yield. Thus, finding robust crops is critical for maintaining the food supply. This PhD project aimed to understand the underlying mechanisms of morphological, physiological and biochemical responses in selected Nordic wheat genotypes (heat-sensitive and heat-tolerant genotypes) under drought and heat stress at ambient and elevated CO2 levels. High-throughput phenotyping, gas exchange, chlorophyll fluorescence and targeted metabolomic profiling were used to assess the performance of the genotypes under abiotic stress. The results showed different responses among the selected genotypes to heat and combined drought and heat more than to moderate drought stress. Under heat stress, the responses of the heat-tolerant genotypes were found different between parameters such as increased transpiration rate compared to heat-sensitive genotypes. However, under combined drought and heat, the overall stress effect was amplified and the potential of genotypes to cope with such stress was revealed. Some of the heat-sensitive genotypes showed enhanced responses including higher photosynthesis, water use efficiency and the synthesis of compatible solutes under combined stress, particularly when plants were grown under elevated CO2. Thus, the mitigation effect of elevated CO2 under moderate drought and heat stress was genotype dependent. Moreover, in this study the responses to the stress applied at different developmental stages showed that the combination of stress types at anthesis was more severe as reflected in lower gas exchange parameters and maximum quantum efficiency of PSII com-pared to that at tillering and the negative impact of stress was observed on the grain yield. The findings in this PhD project highlight the necessity of investigating the effect of combined stress types in revealing the genotype potential to cope with stress. In addition, the applied phenotyping approach is useful for selecting climate-resilient genotypes. The results contribute to a better understanding of the physiological and biochemical responses among different genotypes that are important to develop robust crops for the future.

AB - Climate change already has an impact on agricultural productivity and food security. The continuously rising CO2 concentration contributes to global warming. Wheat is one of the global cereal crops that is highly in demand but is threatened by warmer and drier weather patterns that lower the yield. Thus, finding robust crops is critical for maintaining the food supply. This PhD project aimed to understand the underlying mechanisms of morphological, physiological and biochemical responses in selected Nordic wheat genotypes (heat-sensitive and heat-tolerant genotypes) under drought and heat stress at ambient and elevated CO2 levels. High-throughput phenotyping, gas exchange, chlorophyll fluorescence and targeted metabolomic profiling were used to assess the performance of the genotypes under abiotic stress. The results showed different responses among the selected genotypes to heat and combined drought and heat more than to moderate drought stress. Under heat stress, the responses of the heat-tolerant genotypes were found different between parameters such as increased transpiration rate compared to heat-sensitive genotypes. However, under combined drought and heat, the overall stress effect was amplified and the potential of genotypes to cope with such stress was revealed. Some of the heat-sensitive genotypes showed enhanced responses including higher photosynthesis, water use efficiency and the synthesis of compatible solutes under combined stress, particularly when plants were grown under elevated CO2. Thus, the mitigation effect of elevated CO2 under moderate drought and heat stress was genotype dependent. Moreover, in this study the responses to the stress applied at different developmental stages showed that the combination of stress types at anthesis was more severe as reflected in lower gas exchange parameters and maximum quantum efficiency of PSII com-pared to that at tillering and the negative impact of stress was observed on the grain yield. The findings in this PhD project highlight the necessity of investigating the effect of combined stress types in revealing the genotype potential to cope with stress. In addition, the applied phenotyping approach is useful for selecting climate-resilient genotypes. The results contribute to a better understanding of the physiological and biochemical responses among different genotypes that are important to develop robust crops for the future.

M3 - PhD thesis

SN - 9788794253093

PB - Århus Universitet

ER -