Molecular Breeding for Maize Improvement: An Overview

85-98The maize genome is one of the most extensively analyzed among the plant genomes. Consequently, maize has been at the forefront in development and evaluation of an array of molecular markers for varied purposes in genetics and breeding. Besides the well-demonstrated utility of molecular markers in genotype differentiation and analysis of genetic diversity in maize germplasm, application of DNA-based markers is also of considerable significance to tropical/sub-tropical maize production systems, such as in India, for mapping and marker-assisted selection for resistance to major biotic/abiotic stresses affecting production and productivity. Significant impetus in this direction has been provided in recent years through the Asian Maize Biotechnology Network (AMBIONET). This article provides an overview of the recent efforts under AMBIONET in relation to: (i) the molecular characterization of inbred lines developed by various public sector institutions in India; (ii) the analysis of genetic diversity in the Indian maize germ plasm using microsatellite markers; and (Hi) the mapping of quantitative trait loci conferring resistance to different downy mildews affecting maize in tropical Asia. Judicious integration of conventional and molecular approaches in maize breeding programmes is vital for efficient utilization of genetic resources, and improving the production and post-harvest characteristics of the elite germplasm. This shall, in turn, require further strengthening of synergistic linkages and partnerships among national and international research institutions to harness the rapidly emerging information and technologies related to molecular breeding in maize