Improving blast resistance of maintainer line DRR 9B by transferring broad spectrum resistance gene by marker assisted selection in rice.

Hybrid rice technology offers great promise to further enhance rice production and productivity for global food security. Improving hybrid rice parental lines is the first step in developing heterotic rice hybrids. To improve resistance against blast disease, a maintainer line DRR 9B was fortified with a major broad-spectrum blast resistance gene through marker-assisted selection. The rice blast caused by is a major disease and can cause severe yield losses upto 100%. The NILs of Samba Mahsuri namely BA-23-11-89-12-168 possessing was utilized as a donor parent. The PCR-based molecular marker tightly linked to gene was used for the foreground selection at BCF generation. The molecular marker tightly linked to the major fertility restorer gene was used for negative selection (i.e., selection of plants possessing non fertility restoring alleles) at BCF generation to identify maintainer lines. The positive plants with gene were added to the restorer pool for restorer line development. At each stage, MAS for coupled with stringent phenotypic selection for agro-morphological and grain quality traits were exercised. At BCF generation, one hundred families were screened against blast disease at uniform blast nursery (UBN) and selected resistant lines were advanced to next generations. In the BCF generation plants were subjected to agro-morphological evaluation for yield and yield-contributing traits. The selected plants at BCF generation were crossed with DRR 9A to assess the maintainer ability of blast resistance lines and for further CMS line conversion for hybrid rice breeding for developing blast resistance rice hybrids.