Genome-wide association studies identify resistance loci to orange rust and yellow leaf virus diseases in a diversity panel of polyploid sugarcane (Saccharum spp.)

Authors: YANG, XIPING - University Of Florida; Sood, Sushma; LUO, ZILIANG - University Of Florida; Todd, James; WANG, JIANPING - University Of Florida

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2018
Publication Date: 3/6/2019
Citation: Yang, X., Sood, S.G., Luo, Z., Todd, J.R., Wang, J. 2019. Genome-wide association studies identify resistance loci to orange rust and yellow leaf virus diseases in a diversity panel of polyploid sugarcane (Saccharum spp.). Phytopathology. 109(4):623-631. https://doi.org/10.1094/Phyto-08-18-0282-R.
DOI: https://doi.org/10.1094/Phyto-08-18-0282-R

Interpretive Summary: Sugarcane orange rust and sugarcane yellow leaf virus are major threats to sugarcane, an energy-efficient C4 plant, contributes up to 80% of sugar and approximately 60% of bio-fuel globally. Using resistant sugarcane cultivars is most economical and environmentally friendly control measure to these diseases in commercial production. Dissecting DNA sequence variants controlling disease resistance are fundamental for fulfilling this strategy in sugarcane breeding programs by providing valuable genetic resources and tools. In this study, we evaluated disease resistance reactions to orange rust and sugarcane yellow leaf virus of a sugarcane diversity panel consisting of 308 accessions primarily selected from the “world collection of sugarcane and related grasses” in repeated trials. Our results emphasized the importance to utilize a wide germplasm for breeding resistant sugarcane cultivars.

Technical Abstract: Sugarcane orange rust and sugarcane yellow leaf virus (SCYLV), which can cause up to 50% and 40% yield loss respectively, are major threats to sugarcane (Saccharum spp.), an energy-efficient C4 plant, contributes up to 80% of sugar and approximately 60% of bio-fuel globally. To control the two diseases efficiently, it is critical to breed and use resistant sugarcane cultivars to the diseases in commercial production. Dissecting DNA sequence variants controlling disease resistance are fundamental for fulfilling this strategy in sugarcane breeding programs by providing valuable genetic resources and tools. In this study, we evaluated disease resistance reactions to orange rust and SCYLV of a sugarcane diversity panel consisting of 308 accessions primarily selected from the “world collection of sugarcane and related grasses” in repeated trials. We further conducted genome-wide association study between the high-density markers and traits. In total, 91 non-redundant markers and 82 candidate genes were identified to be significantly associated with resistance reactions to the two diseases evaluated, which can serve as a comprehensive genetic resource for gene identification, characterization, and selection for sugarcane improvement. Our results emphasized the importance to utilize a wide germplasm for breeding resistant sugarcane cultivars.