High-throughput phenotyping to detect drought tolerance QTL in wild barley introgression lines.
Drought is one of the most severe stresses, endangering crop yields worldwide. In order to select drought tolerant genotypes, access to exotic germplasm and efficient phenotyping protocols are needed. In this study the high-throughput phenotyping platform "The Plant Accelerator", Adelaide, Australia, was used to screen a set of 47 juvenile (six week old) wild barley introgression lines (S42ILs) for drought stress responses. The kinetics of growth development was evaluated under early drought stress and well watered treatments. High correlation (r=0.98) between image based biomass estimates and actual biomass was demonstrated, and the suitability of the system to accurately and non-destructively estimate biomass was validated. Subsequently, quantitative trait loci (QTL) were located, which contributed to the genetic control of growth under drought stress. In total, 44 QTL for eleven out of 14 investigated traits were mapped, which for example controlled growth rate and water use efficiency. The correspondence of those QTL with QTL previously identified in field trials is shown. For instance, six out of eight QTL controlling plant height were also found in previous field and glasshouse studies with the same introgression lines. This indicates that phenotyping juvenile plants may assist in predicting adult plant performance. In addition, favorable wild barley alleles for growth and biomass parameters were detected, for instance, a QTL that increased biomass by approximately 36%. In particular, introgression line S42IL-121 revealed improved growth under drought stress compared to the control Scarlett. The introgression line showed a similar behavior in previous field experiments, indicating that S42IL-121 may be an attractive donor for breeding of drought tolerant barley cultivars.
Chair of Plant Breeding, Institute of Agricultural and Nutritional Sciences, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany; Interdisciplinary Center for Crop Plant Research (IZN), Halle (Saale), Germany.
Nora
N
Honsdorf
School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Adelaide, Australia.
Timothy John
TJ
March
The Plant Accelerator, University of Adelaide, Waite Campus, Adelaide, Australia.
Bettina
B
Berger
Center for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Mark
M
Tester
Chair of Plant Breeding, Institute of Agricultural and Nutritional Sciences, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany.
Klaus
K
Pillen
D000220:Adaptation, Biological / Q000235:genetics*; D000704:Analysis of Variance; D001947:Breeding / Q000379:methods; D055864:Droughts; D005828:Genetics, Population; D001467:Hordeum / Q000235:genetics* / Q000254:growth & development*; D006824:Hybridization, Genetic / Q000235:genetics*; D008957:Models, Genetic; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics*; D013045:Species Specificity