Genomic characterization of blast resistant lines in the background of Improved Samba Mahsuri using genome wide SSR markers

Rice (Oryza sativa L.) is the most extensively cultivated and consumed grain and it is considered as lifeline for more than half of world's population. Blast and Bacterial leaf blight (BLB) are major diseases among biotic stresses which seriously limiting crop productivity. Hence, developing disease resistance lines is important in sustainability of rice production. In the present study, five blast resistance lines developed in background of elite rice variety improved samba mahsuri were genotyped with genome wide SSR markers and genomic differences were established. Genomic differences were studied in four combinations of ISM-MLPi54/ ISM-MLPi9, ISM-MLPi54/ ISM-MLPi20, ISM-MLPi54/ ISM-MLP40 and ISM-MLPi54/ ISM-MLPita. The results have shown that, among 1800 screened SSR markers, 63 were found to be polymorphic markers between ISM-MLPi54/ISM-MLPi9, 57 polymorphic markers between ISM-MLPi54/ISM-MLPi20, 55 polymorphic markers between ISM-MLPi54/ISM-MLPi40 and 60 polymorphic markers between ISM-MLPi54/ISM-MLPita. Number of polymorphic markers on each chromosome was found varying from 3 to 10 among four combinations with average of five markers per chromosome. Similarly, % polymorphism was varying from 1.67-5.98% with average of 3.16-3.52% per chromosome. Results of this study greatly enhance molecular insights in these blast resistance lines and their efficient use in further blast disease resistance breeding programmes.