Quantitative Traits Loci Associated with Biotic and Abiotic Resistance in Maize (Zea mays L.)

Maize is an essential crop rank first, cultivated all over the world. Maize is being consumed by both humans and animals inspite that it is utilized as an industrial product viz., starch, pharmaceuticals, alcoholic beverages, oil, cosmetics, textiles, etc. In ancient times, landraces were more popular due to presence of more genetic variability, resistant to biotic and abiotic factors and have heterogeneous nature. But due to continuous use of uniform cultivars, landraces were replaced by higher yielder. Modern maize has more homogeneity which is vulnerable to any dangerous pathogen strain. In the current era of molecular markers, DNA markers play an important role to identify diverse germplasm/cultivars. To evaluate the diversity of maize, several mapping populations are developed and used for QTL mapping. Linkage mapping was first used in maize in the 1990s and is still common now along with genome-wide association mapping. Association mapping has been preferred due to the conserved historical linkage disequilibrium and elimination for the construction of a bi-parental mapping population. In this review, we focused, how much work on genome mapping has been done and what is the prospect of genome mapping.