High-resolution spectral information enables phenotyping of leaf epicuticular wax in wheat
Abstract Background Epicuticular wax (EW) is the first line of defense in plants for protection against biotic and abiotic factors in the environment. In wheat, EW is associated with resilience to heat and drought stress, however, the current limitations on phenotyping EW restrict the integration of...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2021-06-01
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| Series: | Plant Methods |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13007-021-00759-w |
| _version_ | 1819099788573933568 |
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| author | Fátima Camarillo-Castillo Trevis D. Huggins Suchismita Mondal Matthew P. Reynolds Michael Tilley Dirk B. Hays |
| author_facet | Fátima Camarillo-Castillo Trevis D. Huggins Suchismita Mondal Matthew P. Reynolds Michael Tilley Dirk B. Hays |
| author_sort | Fátima Camarillo-Castillo |
| collection | DOAJ |
| description | Abstract Background Epicuticular wax (EW) is the first line of defense in plants for protection against biotic and abiotic factors in the environment. In wheat, EW is associated with resilience to heat and drought stress, however, the current limitations on phenotyping EW restrict the integration of this secondary trait into wheat breeding pipelines. In this study we evaluated the use of light reflectance as a proxy for EW load and developed an efficient indirect method for the selection of genotypes with high EW density. Results Cuticular waxes affect the light that is reflected, absorbed and transmitted by plants. The narrow spectral regions statistically associated with EW overlap with bands linked to photosynthetic radiation (500 nm), carotenoid absorbance (400 nm) and water content (~ 900 nm) in plants. The narrow spectral indices developed predicted 65% (EWI-13) and 44% (EWI-1) of the variation in this trait utilizing single-leaf reflectance. However, the normalized difference indices EWI-4 and EWI-9 improved the phenotyping efficiency with canopy reflectance across all field experimental trials. Indirect selection for EW with EWI-4 and EWI-9 led to a selection efficiency of 70% compared to phenotyping with the chemical method. The regression model EWM-7 integrated eight narrow wavelengths and accurately predicted 71% of the variation in the EW load (mg·dm−2) with leaf reflectance, but under field conditions, a single-wavelength model consistently estimated EW with an average RMSE of 1.24 mg·dm−2 utilizing ground and aerial canopy reflectance. Conclusions Overall, the indices EWI-1, EWI-13 and the model EWM-7 are reliable tools for indirect selection for EW based on leaf reflectance, and the indices EWI-4, EWI-9 and the model EWM-1 are reliable for selection based on canopy reflectance. However, further research is needed to define how the background effects and geometry of the canopy impact the accuracy of these phenotyping methods. |
| first_indexed | 2024-12-22T00:52:27Z |
| format | Article |
| id | doaj.art-b2f19594cac14e6094e334678f4b8550 |
| institution | Directory Open Access Journal |
| issn | 1746-4811 |
| language | English |
| last_indexed | 2024-12-22T00:52:27Z |
| publishDate | 2021-06-01 |
| publisher | BMC |
| record_format | Article |
| series | Plant Methods |
| spelling | doaj.art-b2f19594cac14e6094e334678f4b85502022-12-21T18:44:25ZengBMCPlant Methods1746-48112021-06-0117111710.1186/s13007-021-00759-wHigh-resolution spectral information enables phenotyping of leaf epicuticular wax in wheatFátima Camarillo-Castillo0Trevis D. Huggins1Suchismita Mondal2Matthew P. Reynolds3Michael Tilley4Dirk B. Hays5Global Wheat Program, International Maize and Wheat Improvement Center (CIMMYT)USDA ARS, Dale Bumper National Rice Research CenterGlobal Wheat Program, International Maize and Wheat Improvement Center (CIMMYT)Global Wheat Program, International Maize and Wheat Improvement Center (CIMMYT)Agricultural Research Service, Center for Grain and Animal Health Research, USDADepartment of Soil and Crop Sciences, Texas A&M UniversityAbstract Background Epicuticular wax (EW) is the first line of defense in plants for protection against biotic and abiotic factors in the environment. In wheat, EW is associated with resilience to heat and drought stress, however, the current limitations on phenotyping EW restrict the integration of this secondary trait into wheat breeding pipelines. In this study we evaluated the use of light reflectance as a proxy for EW load and developed an efficient indirect method for the selection of genotypes with high EW density. Results Cuticular waxes affect the light that is reflected, absorbed and transmitted by plants. The narrow spectral regions statistically associated with EW overlap with bands linked to photosynthetic radiation (500 nm), carotenoid absorbance (400 nm) and water content (~ 900 nm) in plants. The narrow spectral indices developed predicted 65% (EWI-13) and 44% (EWI-1) of the variation in this trait utilizing single-leaf reflectance. However, the normalized difference indices EWI-4 and EWI-9 improved the phenotyping efficiency with canopy reflectance across all field experimental trials. Indirect selection for EW with EWI-4 and EWI-9 led to a selection efficiency of 70% compared to phenotyping with the chemical method. The regression model EWM-7 integrated eight narrow wavelengths and accurately predicted 71% of the variation in the EW load (mg·dm−2) with leaf reflectance, but under field conditions, a single-wavelength model consistently estimated EW with an average RMSE of 1.24 mg·dm−2 utilizing ground and aerial canopy reflectance. Conclusions Overall, the indices EWI-1, EWI-13 and the model EWM-7 are reliable tools for indirect selection for EW based on leaf reflectance, and the indices EWI-4, EWI-9 and the model EWM-1 are reliable for selection based on canopy reflectance. However, further research is needed to define how the background effects and geometry of the canopy impact the accuracy of these phenotyping methods.https://doi.org/10.1186/s13007-021-00759-wPlant cuticleVegetation indicesHigh-throughput phenotypingWheat breeding |
| spellingShingle | Fátima Camarillo-Castillo Trevis D. Huggins Suchismita Mondal Matthew P. Reynolds Michael Tilley Dirk B. Hays High-resolution spectral information enables phenotyping of leaf epicuticular wax in wheat Plant Methods Plant cuticle Vegetation indices High-throughput phenotyping Wheat breeding |
| title | High-resolution spectral information enables phenotyping of leaf epicuticular wax in wheat |
| title_full | High-resolution spectral information enables phenotyping of leaf epicuticular wax in wheat |
| title_fullStr | High-resolution spectral information enables phenotyping of leaf epicuticular wax in wheat |
| title_full_unstemmed | High-resolution spectral information enables phenotyping of leaf epicuticular wax in wheat |
| title_short | High-resolution spectral information enables phenotyping of leaf epicuticular wax in wheat |
| title_sort | high resolution spectral information enables phenotyping of leaf epicuticular wax in wheat |
| topic | Plant cuticle Vegetation indices High-throughput phenotyping Wheat breeding |
| url | https://doi.org/10.1186/s13007-021-00759-w |
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