Remote sensing based evaluation of heat tolerance in tropical bread wheat using spectral reflectance indices
Thankachan, D.
Remote sensing based evaluation of heat tolerance in tropical bread wheat using spectral reflectance indices - Bonn (Germany) : University of Hohenheim : ATSAF : CIMMYT, 2025. - 1 page
Presented at Tropentag 2025: International Conference on Research for Sustainable Development, September 10–12, Hybrid Conference.
Wheat productivity is significantly constrained by climate change–induced drought stress, often compounded by high irradiance, which inhibits photosynthesis and reduces yield. Spectral reflectance indices (SRIs) can assess physiological traits, including leaf pigments, as rapid, nondestructive proxies for drought response. This study identified genotypic variation among 24 spring wheat Lines under water-deficit (WD) conditions using SRIs and evaluated their association with crop performance. The experiment was conducted during the 2023/2024 season at CIMMYT’s field station in Ciudad Obregón, Sonora, Mexico. SRIs for Anthocyanin Reflectance Index (ARI), Carotenoid Reflectance Index (CRI), Ratio Analysis of Carotenoids (RARSc), Structure Insensitive Pigment Index (SIPI), Photochemical Reflectance Index (PRI), Normalised Difference Vegetation Index (NDVI), Ratio Analysis of Chlorophyll a (RARSa), Ratio Analysis of Chlorophyll b (RARSb), Water Index (WI), and Normalised Difference Water Index (NDWI) were used to assess physiological status at early reproductive and maturation stages. ARI increased under WD across both stages, indicating higher anthocyanin accumulation for photoprotection and antioxidant defence. PRI reduction under WD reflected increased xanthophyll cycle de-epoxidation and excess energy dissipation, while CRI and RARSc were higher under well-watered (WW) conditions, suggesting inhibition of carotenoid biosynthesis under WD. NDVI consistently declined under WD due to reduced green biomass, whereas SPAD values showed limited variation and contribution to principal component analysis. Chlorophyll index RARSa increased under WD in most Lines. WI and NDWI significantly decreased under WD. On average, grain yield and biomass were reduced by 46 % and 48 %, respectively. SRIs (PRI, NDVI, CRI, RARSc, RARSb, WI, NDWI) showed strong positive correlations with yield and biomass, while ARI, SIPI, and RARSa were negatively associated across stages and environments. Two Lines were drought-adapted, and two were drought-sensitive. Overall, SRIs proved reliable for identifying high-yielding, drought-resilient Lines, supporting their use in breeding for water-limited conditions.
Text in English
Remote sensing
Heat tolerance
Soft wheat
Reflectance
Remote sensing based evaluation of heat tolerance in tropical bread wheat using spectral reflectance indices - Bonn (Germany) : University of Hohenheim : ATSAF : CIMMYT, 2025. - 1 page
Presented at Tropentag 2025: International Conference on Research for Sustainable Development, September 10–12, Hybrid Conference.
Wheat productivity is significantly constrained by climate change–induced drought stress, often compounded by high irradiance, which inhibits photosynthesis and reduces yield. Spectral reflectance indices (SRIs) can assess physiological traits, including leaf pigments, as rapid, nondestructive proxies for drought response. This study identified genotypic variation among 24 spring wheat Lines under water-deficit (WD) conditions using SRIs and evaluated their association with crop performance. The experiment was conducted during the 2023/2024 season at CIMMYT’s field station in Ciudad Obregón, Sonora, Mexico. SRIs for Anthocyanin Reflectance Index (ARI), Carotenoid Reflectance Index (CRI), Ratio Analysis of Carotenoids (RARSc), Structure Insensitive Pigment Index (SIPI), Photochemical Reflectance Index (PRI), Normalised Difference Vegetation Index (NDVI), Ratio Analysis of Chlorophyll a (RARSa), Ratio Analysis of Chlorophyll b (RARSb), Water Index (WI), and Normalised Difference Water Index (NDWI) were used to assess physiological status at early reproductive and maturation stages. ARI increased under WD across both stages, indicating higher anthocyanin accumulation for photoprotection and antioxidant defence. PRI reduction under WD reflected increased xanthophyll cycle de-epoxidation and excess energy dissipation, while CRI and RARSc were higher under well-watered (WW) conditions, suggesting inhibition of carotenoid biosynthesis under WD. NDVI consistently declined under WD due to reduced green biomass, whereas SPAD values showed limited variation and contribution to principal component analysis. Chlorophyll index RARSa increased under WD in most Lines. WI and NDWI significantly decreased under WD. On average, grain yield and biomass were reduced by 46 % and 48 %, respectively. SRIs (PRI, NDVI, CRI, RARSc, RARSb, WI, NDWI) showed strong positive correlations with yield and biomass, while ARI, SIPI, and RARSa were negatively associated across stages and environments. Two Lines were drought-adapted, and two were drought-sensitive. Overall, SRIs proved reliable for identifying high-yielding, drought-resilient Lines, supporting their use in breeding for water-limited conditions.
Text in English
Remote sensing
Heat tolerance
Soft wheat
Reflectance