Development of salinity tolerant version of a popular rice variety improved white ponni through marker assisted back cross breeding

Salinity is one of the major abiotic stress limiting rice productivity under marginal environments. The progress in development of salinity tolerant rice varieties is slow due to complex nature of tolerance mechanisms determining performance under salinity. In the present study, efforts were taken to generate NILs of a popular rice genotype Improved White Ponni exhibiting increased tolerance against salinity through marker assisted introgression of ‘Saltol’, a major effect QTL of FL478. IWP-Satol NILs exhibited enhanced tolerance against salinity under hydroponic conditions. MABB approach accelerated the development of NILs with high recovery of recurrent parent genome within 2–3 backcrosses. Genotyping and phenotyping of BC3F1 progenies resulted in the identification of elite NILs of IWP harboring Saltol loci and possessing > 90% of recurrent parent genome recovery. Selected NILs viz., 5-35, 5-36 and 5-45 that carried the Saltol loci were screened under field conditions for their agronomic traits. NIL # 5-36 exhibited superior agronomic performance (58% increased yield over IWP under saline conditions) and superior grain/cooking quality traits than that of IWP.