Location: Crop Genetics and Breeding ResearchTitle: Mapping late leaf spot resistance in peanut (Arachis hypogaea) using QTL-seq reveals markers for marker-assisted selection
|CLEVENGER, J - Mars, Inc|
|CHU, Y - University Of Georgia|
|CHAVARRO, C - University Of Georgia|
|BOTTON, S - University Of Georgia|
|CULBREATH, A - University Of Georgia|
|ISLEIB, T - North Carolina State University|
|Holbrook, Carl - Corley|
|OZIAS-AKINS, P - University Of Georgia|
Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2018
Publication Date: 2/5/2018
Citation: Clevenger, J., Chu, Y., Chavarro, C., Botton, S., Culbreath, A.K., Isleib, T.G., Holbrook Jr, C.C., Ozias-Akins, P. 2018. Mapping late leaf spot resistance in peanut (Arachis hypogaea) using QTL-seq reveals markers for marker-assisted selection. Frontiers in Plant Science. 9:83. https://doi.org/10.3389/fpls.2018.00083.
Interpretive Summary: Late leaf spot (LLS) is a major disease in peanut. Many growers use 5 to 7 fungicide sprays in a growing season to control this disease. Resistant varieties would help to reduce cost of disease control while minimizing loss from disease. The development of molecular markers for resistant genes would greatly aid in breeding for resistance. We developed a population that was segregating for resistance to LLS. After genotyping and phenotyping this population we used QTL-seq to discover significant genetic markers for resistant genes. These markers were confirmed over 4 years of field data. Selection with these genetic markers resulted in a significant increase in resistance, showing that these markers can be immediately applied in breeding programs.
Technical Abstract: Late leaf spot (LLS; Cercosporidium personatum) is a major fungal disease of cultivated peanut (Arachis hypogaea). A recombinant inbred line population segregating for quantitative field resistance was used to identify quantitative trait loci (QTL) using QTL-seq. High rates of false positive SNP calls using established methods in this allotetraploid crop obscured significant QTLs. To resolve this problem, robust parental SNPS were first identified using polyploid-specific SNP identification pipelines, leading to discovery of significant QTLs for LLS resistance. These QTLs were confirmed over 4 years of field data. Selection with markers linked to these QTLs resulted in a significant increase in resistance, showing that these markers can be immediately applied in breeding programs. This study demonstrates that QTL-seq can be used to rapidly identify QTLs controlling highly quantitative traits in polyploid crops with complex genomes. Markers identified can then be deployed in breeding programs, increasing the efficiency of selection using molecular tools.