Genetic dissection of bread wheat diversity and identification of adaptive loci in response to elevated tropospheric ozone |
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Authors: | Hasina Begum Muhammad Shahedul Alam Yanru Feng Patrice Koua Md Ashrafuzzaman Asis Shrestha Mohammad Kamruzzaman Said Dadshani Agim Ballvora Ali Ahmad Naz Michael Frei |
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Institution: | 1. Institute of Crop Science and Resource Conservation (INRES), Plant Breeding, University of Bonn, Bonn, Germany;2. Institute of Crop Science and Resource Conservation (INRES), Crop Science, University of Bonn, Bonn, Germany |
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Abstract: | Rising tropospheric ozone affects the performance of important cereal crops thus threatening global food security. In this study, genetic variation of wheat regarding its physiological and yield responses to ozone was explored by exposing a diversity panel of 150 wheat genotypes to elevated ozone and control conditions throughout the growing season. Differential responses to ozone were observed for foliar symptom formation quantified as leaf bronzing score (LBS), vegetation indices and yield components. Vegetation indices representing the carotenoid to chlorophyll pigment ratio (such as Lic2) were particularly ozone-responsive and were thus considered suitable for the non-invasive diagnosing of ozone stress. Genetic variation in ozone-responsive traits was dissected by a genome-wide association study (GWAS). Significant marker-trait associations were identified for LBS on chromosome 5A and for vegetation indices (NDVI and Lic2) on chromosomes 6B and 6D. Analysis of linkage disequilibrium (LD) in these chromosomal regions revealed distinct LD blocks containing genes with a putative function in plant redox biology such as cytochrome P450 proteins and peroxidases. This study gives novel insight into the natural genetic variation in wheat ozone response, and lays the foundation for the molecular breeding of tolerant wheat varieties. |
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Keywords: | air pollution cereals cytochrome P450 proteins genome-wide association study global change molecular breeding ozone stress tolerance vegetation indices |
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