|WANG, RUI - University Of Idaho|
|HOLE, DAVID - Utah State University|
|ZHAO, WEIDONG - University Of Idaho|
|ISHAM, KYLE - University Of Idaho|
|GOATES, BLAIR - Retired ARS Employee|
|CHEN, JIANLI - University Of Idaho|
Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/19/2019
Publication Date: 6/25/2019
Citation: Wang, R., Gordon, T.C., Hole, D., Zhao, W., Isham, K., Bonman, J.M., Goates, B., Chen, J. 2019. Identification and assessment of two major QTL for dwarf bunt resistance in Winter Wheat Line ‘IDO835’. Journal of Theoretical and Applied Genetics. 132:2755-2766. https://doi.org/10.1007/s00122-019-03385-2.
Interpretive Summary: Dwarf bunt disease of winter wheat is important in organic production systems. Breeding for resistance to dwarf bunt is the primary means of control of the disease in organic wheat. However, field trials to screen for dwarf bunt resistance are time consuming and difficult. In this study, we identified resistance genes on two wheat chromosomes and found molecular markers linked to these genes that can be used by breeders to select for resistance. These markers will enable selection for resistance without expensive field trials and will assist wheat breeders in developing new, dwarf bunt resistant wheat cultivars.
Technical Abstract: Dwarf bunt (DB), caused by Tilletia controversa J.G. Kühn, and common bunt (CB), caused by T. caries and T. foetida, are two destructive diseases that reduce grain yield and quality in wheat. Breeding for bunt-resistant cultivars is important in many wheat production areas, especially where organic wheat is grown. However, few molecular markers have been used in selection of bunt resistance. In the present study, a doubled haploid (DH) population derived from the buntresistant line ‘IDO835’ and the susceptible cultivar ‘Moreland’ was evaluated for DB resistance in a field nursery in Logan, Utah, for four growing seasons. The population was genotyped with the Illumina 90 K SNP iSelect marker platform. Two major QTLs were consistently identified on chromosomes 6DL (Q.DB.ui-6DL) and 7AL (Q.DB.ui-7AL), explaining up to 53% and 38% of the phenotypic variation, respectively. Comparative study suggested that Q.DB.ui-6DL was located in the same region as the CB resistance gene Bt9, and Q.DB.ui-7AL was located at a novel locus for bunt resistance. Based on Chinese Spring reference sequence and annotations (IWGSC RefSeq v1.1), both resistance QTLs were mapped to disease resistance gene-rich (NBS-LRR and kinase genes) regions. To validate the identified QTL and design user-friendly markers for MAS, five SNPs were converted to Kompetitive Allele-Specific PCR (KASP) markers and used to genotype two validation panels, including a DH population and a diverse winter wheat population from USDA-ARS National Small Grain Collection, as well as a Bt gene investigation panel, consisting of 15 bunt differential lines and 11 resistant lines.