Downy mildew was described for first time in india by
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Downy mildew occurs in sunflower-growing areas in all parts of the world and becomes especially epidemic during wet spring years. Downy mildew is constantly developing new races. At least 18 downy mildew races have been observed up to the moment, but resistant genes have been successfully controlled by transferring PI genes from wild sunflower species (Škorić et al. 2006; Bán et al., 2014; Sakr, 2014). Using metalaxyl as a chemical control for seed treatment is an efficient method. However, new races cannot be controlled by metalaxyl treatment, so sunflower breeders use the US Department of Agriculture (USDA) public lines having PI genes such as RHA-340 and RHA-419 to develop durable resistance. Furthermore, to get better downy mildew resistance, sunflower breeders need to develop new resistant genotypes with genes that are more resistant by making use of different resistance sources to achieve vertical and horizontal resistance against downy mildew in breeding programs. In addition to classical breeding efforts, different molecular studies especially for marker-assisted selection (MAS) have been performed to speed up selection cycles and also to characterize dominant genes in the genotypes (Liu et al., 2012). Breeding materials have been tested by inoculation methods which has brought about continuous improvements in determining downy mildew resistance (Vear et al. 2000; Molinaro-Demilly et al., 2004; Tourvieille de Labrouhe et al., 2004; Škorić, 2012; Sakr, 2014).