| Description: |
Sheath blight is a damaging rice disease caused by the fungi Rhizoctonia solani, leading to significant yield loss. Currently, there are no identified sources of complete resistance to the disease, as it is controlled by numerous minor genes. To tackle this issue, we conducted a study with a diversity panel comprising 228 indica lines, screening for sheath blight resistance. Through genome-wide association study, we identified QTLs (Quantitative Trait Loci) for three components of the disease which are lesion number, maximum lesion length, and vertical sheath colonization, along with donor lines associated with each QTL. To develop durable resistance against sheath blight, we performed a multiway cross, aiming to combine these QTLs into a single line. From the multiway cross population, we selected 15 lines that displayed good resistance under microfield conditions. These lines were further validated through controlled environment screening, resulting in 8 lines performing at par or even better than our resistant control. This demonstrates that pyramiding of QTLs linked to the different disease components contributes to generating lines with durable resistance, which in turn can be used in breeding for rice sheath blight resistance. |