Adaptive Traits to Improve Durum Wheat Yield in Drought and Crown Rot Environments

• Published in: International journal of molecular sciences Vol. 21; no. 15; p. 5260
• Main Authors: Alahmad, Samir, Kang, Yichen, Dinglasan, Eric, Mazzucotelli, Elisabetta, Voss-Fels, Kai P, Able, Jason A, Christopher, Jack, Bassi, Filippo M, Hickey, Lee T
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 24-07-2020; MDPI
• Subjects: Adaptation; Agricultural production; Alleles; association mapping; Barley; Cereals; Chromosome Mapping; Chromosomes; Chromosomes, Plant - genetics; Chromosomes, Plant - metabolism; Computer architecture; Controlled conditions; Crop diseases; Crop yield; Crops; Crosses, Genetic; Crown rot; Dehydration - genetics; Dehydration - metabolism; Drought; drought adaptation; fusarium; Gene mapping; Genome-Wide Association Study; Genomes; Genotypes; Germplasm; Mapping; Normalized difference vegetative index; Physiology; Quantitative Trait Loci; Rain; root architecture; Senescence; Sorghum; stay-green; Triticum - genetics; Triticum - growth & development; Triticum durum; Triticum turgidum; Water shortages; Water stress; water use; Wheat; Australia; stay-green; root architecture; drought adaptation; water use; association mapping; fusarium
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21155260

Durum wheat (
L. ssp.
) production can experience significant yield losses due to crown rot (CR) disease. Losses are usually exacerbated when disease infection coincides with terminal drought. Durum wheat is very susceptible to CR, and resistant germplasm is not currently available in elite breeding pools. We hypothesize that deploying physiological traits for drought adaptation, such as optimal root system architecture to reduce water stress, might minimize losses due to CR infection. This study evaluated a subset of lines from a nested association mapping population for stay-green traits, CR incidence and yield in field experiments as well as root traits under controlled conditions. Weekly measurements of normalized difference vegetative index (NDVI) in the field were used to model canopy senescence and to determine stay-green traits for each genotype. Genome-wide association studies using DArTseq molecular markers identified quantitative trait loci (QTLs) on chromosome 6B (
) associated with CR tolerance and stay-green. We explored the value of
and a major QTL for root angle QTL
using yield datasets from six rainfed environments, including two environments with high CR disease pressure. In the absence of CR, the favorable allele for
provided an average yield advantage of 0.57 t·ha
, whereas in the presence of CR, the combination of favorable alleles for both
and
resulted in a yield advantage of 0.90 t·ha
. Results of this study highlight the value of combining above- and belowground physiological traits to enhance yield potential. We anticipate that these insights will assist breeders to design improved durum varieties that mitigate production losses due to water deficit and CR.