Maize is an economically and nutritionally important cereal crop being cultivated in different agricultural zones under diverse situations of rainfall and altitude around the world. In India, the importance of maize among farming community is increasing as compared to other cereal crops, it is mainly because of availability of high yielding single cross hybrids (Sharma et. ai, 2018). That status is only likely to become more apparent in the next decade. However, the incidence of a range of foliar diseases has become a severe yield limiting factor in most maize producing regions throughout the country. During the past few decades, a major fungal foliar disease of maize called maydis leaf blight (MLB) or southern corn leaf blight (SCLB) is a serious and wide spread disease which causes substantial yield losses worldwide. It is responsible for one of the major causes of low yield in Kharif season. In India, significant damage has already been reported in maize growing areas demonstrating that this disease is a major disease. The disease has potential to reduce grain yield upto the extent of 41 per cent in susceptible cultivars (Sharma and Rai, 2005). In Haryana, disease appears every year ranging from 20-85 per cent and causes significant yield losses (Mehra, 2011; Mehra and Singh, 2016). The rapid progress has been made in recent years in the genetic characterization of disease resistance but, progress in the understanding of the genetic and physiological processes underlying disease resistance hasbeen limited due to their complexity and incomplete and variable expression. As of now, no known genes confer complete immunity to this disease, therefore, maize breeders rely on polygenic, quantitative resistance to maydis leaf blight and the use of molecular markers for characterization of the disease has been used for many of the major maizediseases, and has provided insight for the basis of quantitative resistance (Prasanna et al., 2010). Preselection using molecular markers can reduce the size of a population, and the markers can identify desirable genotypes in the early seedling stage without disturbance by environmental effects. In recent years, microsatellites or simple sequence repeats (SSRs), have been recognized as useful molecular markers in marker-assisted selection (MAS), the analysis of genetic diversity, population analysis, and other purposes in various species (Gupta and Varshney, 2000). Therefore, the information on the aspects of the study of genetic nature of resistance of the disease and aid of molecular markers may help in selection and adoption of breeding approachessuitable for improving yield, quality and disease resistance.
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