Genome-Wide Association Studies Identified Resistance Loci to Orange Rust and Yellow Leaf Virus Diseases in Sugarcane (Saccharum spp.).

Sugarcane (Saccharum spp.) supplies globally ∼80% of table sugar and 60% of bioethanol. Sugarcane orange rust and Sugarcane yellow leaf virus (SCYLV) are major sugarcane diseases, causing up to 50 and 40% yield losses, respectively. Sugarcane cultivars resistant to these diseases are needed to sustain sugarcane production in several regions. Dissecting DNA sequence variants controlling disease resistance provides a valuable tool for fulfilling a breeding strategy to develop resistant cultivars. In this study, we evaluated disease reactions to orange rust and SCYLV of a sugarcane diversity panel in repeated trials. We conducted a genome-wide association study between high-density markers and disease resistance reactions. We identified 91 putative DNA markers and 82 candidate genes significantly associated with resistance to one of the two diseases. These provide an important genetic resource for finding genes and molecular markers for disease resistance. Our results emphasized the importance of utilizing a wide germplasm collection for breeding resistant sugarcane cultivars.