Recent Advances in Rice Breeding Using Biotechnological and Genomics Tools

The area and production of rice have increased drastically since 1965, making it second major crop of the world and first for the prior countries. The major breakthrough in the productivity of rice resulted in green revolution which may be regarded as the threshold line for the advancement in rice cultivation. The development of technologies in the area of breeding, biotechnology and sequencing is the major driving force for boosting the rice production. The content of this chapter presents the glimpses of development of improved rice varieties through the intervention of biotechnological approaches such as genome sequencing, molecular marker technologies, etc. The varietal development through rice breeding programme involves pure line selections and hybrid rice technologies. The biotechnological approaches, DNA marker technologies, genome sequencing and genetic engineering, improve the rice breeding at parent selection, trait mapping and their introgression at early stages, thereby reducing the time, labour and cost of development of improved varieties with high precision. The involvement of marker technologies leads to the development of an area of marker-assisted breeding, marker-assisted backcross programme, marker-assisted gene pyramiding and marker-assisted recurrent selection. The genome sequencing increases the density of DNA markers at base level such as SNP improving the genotyping of mass population through chip and array type platform, genomic selection, association mapping and allele mining. The major genomic sites have been mapped for qualitative traits, viz., biotic and abiotic stress tolerances, nutritional improvement, and the quantitative traits such as yield-related traits like blast resistance, bacterial leaf blight resistance, gall midge resistance, salt tolerance, submergence tolerance, drought tolerance, high Fe and Zn content, dwarf stature, etc.