Rosa Mérida-García ¹ Sergio Gálvez Rojas ² Ignacio Solís ³ Fernando Martinez ³ Carlos Camino ⁴ Jose M. Soriano ⁵ Carolina P. Sansaloni ⁶ Karim Ammar ⁶ Alison R. Bentley ⁷ Victoria Gonzalez-Dugo ¹ Pablo J. ZARCO-TEJADA ^1,8 Pilar Hernandez ^1*

• ¹ Institute for Sustainable Agriculture (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Avenida Menendez Pidal s/n, 14004 Córdoba, Spain, Cordoba, Spain
• ² Department of Languages and Computer Science, ETSI Informática, Campus de Teatinos, Universidad de Málaga, Andalucía Tech, Malaga, Spain
• ³ Department of Agronomy, ETSIA (University of Seville), Ctra de Utrera km1, 41013 Seville, Spain, Seville, Spain
• ⁴ European Commission (EC), Joint Research Centre (JRC), Ispra, Italy, Ispra, Italy
• ⁵ Department of Agricultural and Forest Sciences and Engineering, University of Lleida - AGROTECNIO, Av. Rovira Roure 191, 25198, Lleida, Spain
• ⁶ International Maize and Wheat Improvement Center (CIMMYT), Carretera México-Veracruz Km. 45 El Batán, Texcoco, México, Texcoco, Mexico
• ⁷ Research School of Biology, Australian National University, Canberra, Australia, Canberra, Australia
• ⁸ School of Agriculture, Food and Ecosystem Sciences (SAFES), Faculty of Science (FoS), and Faculty of Engineering, and Information Technology (IE-FEIT), University of Melbourne, Melbourne, Australia

High-throughput phenotyping (HTP) provides new opportunities for efficiently dissecting the genetic basis of drought-adaptive traits, which is essential in current wheat breeding programs. The combined use of HTP and genome-wide association (GWAS) approaches has been useful in the assessment of complex traits such as yield, under field stress conditions including heat and drought. The aim of this study was to identify molecular markers associated with yield (YLD) in elite durum wheat that could be explained using hyperspectral indices (HSIs) under drought field conditions in Mediterranean environments in Southern Spain. The HSIs were obtained from hyperspectral imagery collected during the pre-anthesis and anthesis crop stages using an airborne platform. A panel of 536 durum wheat lines were genotyped by sequencing (GBS, DArTseq) to determine population structure, revealing a lack of genetic structure in the breeding germplasm. The material was phenotyped for YLD and 19 HSIs for six growing seasons under drought field conditions at two locations in Andalusia, in southern Spain. GWAS analysis identified 740 significant marker-trait associations (MTAs) across all the durum wheat chromosomes, several of which were common for YLD and the HSIs, and can potentially be integrated into breeding programs. Candidate gene (CG) analysis uncovered genes related to important plant processes such as photosynthesis, regulatory biological processes, and plant abiotic stress tolerance. These results are novel in that they combine high-resolution hyperspectral imaging at the field scale with GWAS analysis in wheat. They also support the use of HSIs as useful tools for identifying chromosomal regions related to the heat and drought stress response in wheat, and pave the way for the integration of field HTP in wheat breeding programs.