Location: Sunflower and Plant Biology ResearchTitle: Genetic dissection of Phomopsis stem canker resistance in cultivated sunflower using High density SNP linkage map
|TALUKDER, ZAHIRUL - North Dakota State University|
|MA, GUOJIA - North Dakota State University|
|CAI, XIWEN - North Dakota State University|
Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2020
Publication Date: 2/22/2020
Citation: Talukder, Z., Underwood, W., Ma, G., Seiler, G.J., Misar, C.G., Cai, X., Qi, L. 2020. Genetic dissection of Phomopsis stem canker resistance in cultivated sunflower using High density SNP linkage map. International Journal of Molecular Sciences. https://doi.org/10.3390/ijms21041497.
Interpretive Summary: Phomopsis stem canker (PSC) disease in sunflower can result in yield losses as high as 40% and oil loss up to 25%. Host resistance is considered one of the most effective tools for disease management, but is quantitative in nature and governed by mostly additive gene action. Thus, the identification of quantitative trait loci (QTL) for PSC resistance in sunflower holds immediate promise for genetic improvement. In the current study, we report QTL mapping of PSC resistance in a recombinant inbred line population using DNA markers. A total of 15 QTL associated with PSC resistance on 11 sunflower chromosomes was identified, each explaining between 5.24 to 17.39% of the phenotypic variation. The SNP markers flanking the PSC resistance QTL reported in this study will help to facilitate marker-assisted selection in sunflower breeding programs.
Technical Abstract: Phomopsis stem canker (PSC) caused by Diaporthe helianthi is increasingly becoming a global threat for sunflower production. In this study, the genetic basis of PSC resistance was investigated in a recombinant inbred line (RIL) population developed from a cross between HA 89 (susceptible) and HA-R3 (resistant). The RIL population was evaluated for PSC disease incidence (DI) in eight screening trials at multiple locations during 2016-2018. The distribution of PSC DI in the RIL population was continuous, confirming a polygenic inheritance of the trait. A moderately high broad-sense heritability (H2, 0.76) was estimated for the trait across environments. In the combined analysis, both the genotype, and the genotype × environment interactions were highly significant. A linkage map spanning 1,505.33 cM was constructed using genotyping-by-sequencing derived markers. Marker-trait association analysis identified a total of 15 QTL associated with PSC resistance on 11 sunflower chromosomes, each explaining between 5.24 to 17.39% of the phenotypic variation. PSC resistance QTL were detected in two genomic regions each on chromosomes 3, 5, 13 and 17, while one QTL each was detected in the remaining seven chromosomes. Tightly linked SNP markers flanking the PSC resistance QTL will facilitate marker-assisted selection in PSC resistance sunflower breeding.