|SHRESTHA, SURYA - University Of Tennessee
|PAN, WILLIAM - Washington State University
|HULBERT, SCOTT - Washington State University
Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/2022
Publication Date: 12/14/2022
Citation: Shrestha, S.L., Garland-Campbell, K.A., Steber, C.M., Pan, W.L., Hulbert, S.H. 2022. Association of canopy temperature with agronomic traits in spring wheat inbred populations. Euphytica. 219. Article 7. https://doi.org/10.1007/s10681-022-03135-4.
Interpretive Summary: The problem is that drought will continue to impact crop production and methods to assay the performance of plants under drought stress are needed. We evaluated canopy temperature at anthesis stage and spectral reflectance indices to determine if they are associated with grain yield and yield components in two spring wheat populations that are segregating for response to drought. A positive association was detected between canopy temperature and grain yield and between the spectral vegetation and water indices and grain yield. These indices could be used to identify higher-yielding genotypes in a wheat breeding program. Use of these canopy temperature, and the spectral green vegetation and water indices accounted up to 35% of yield variation across the moisture environments which give plant scientists additional tools to evaluate plant response to stress.
Technical Abstract: Low canopy temperature (CT) is a key indicator of drought, and green vegetation and chlorophyll indices are indicators of photosynthetic capacity of plants. The U.S. Pacific Northwest (PNW) adapted wheat cultivars lack stress adaptive traits resulting in a poor performance in drought environments. This study aims to identify stress adaptive trait/s in spring wheat populations. Infrared thermometer and remote sensing methods were used to estimate these parameters in two families of recombinant inbred lines in rainfed and irrigated environments in the PNW. Both CT and green vegetation indices were found to be moderately heritable. Low CT was consistently associated with high yield and high performance of other agronomic traits in most environments. The highest association between CT and yield was observed at anthesis stage in averaged environments (P<0.05). At the same growth stage, the spectral reflectance indices (SRI’s), including green vegetation, chlorophyll and water indices, showed positive association with yield and other agronomy traits in a rainfed environment. The phenological traits had significant effect on both CT and SRI’s. The CT, red normalized difference vegetation index (RNDVI) and spikelets per spike accounted for 35% of yield variation in both rainfed and high moisture environments in the Alpowa/Express population. In the Hollis/Drysdale population, CT, spikelets per spike and heading accounted for 8 to 29% of the yield variation. Our study shows that water uptake (low CT) and photosynthetic (RNDVI) abilities are useful stress adaptive traits for improving wheat performance under water limited conditions in the PNW.