Inheritance of powdery mildew resistance in sunflower (Helianthus annuss L.)

Powdery mildew caused by Golovinomyces cichoracearum is the most important disease on sunflower worldwide. The investigation was undertaken to determine the mode of genetic inheritance of powdery mildew resistance in five F1 and F2 populations of sunflower. The four hybrids were derived by crossing resistant with susceptible genotype and one hybrid between resistant and highly susceptible genotype. Out of 23 hybrids, five crosses viz., PM-22x PM-36, PM-14xPM-36, PM-16xPM-38, PM-17xPM-35 and PM-34x PM-23 were resistant under natural as well as artificial epiphytotic screening conditions and the same five resistant hybrids segregated in 9R:7S ratio in F2 population indicating involvement of two independent loci controlling powdery mildew resistance in sunflower