Development of BioMAGIC population in rice: applications and use in breeding for disease resistance

Rice is prone to different types of biotic stresses resulting to significant yield losses. Breeding for disease resistance is traditionally done through biparental crosses. However, native trait stacking is difficult to achieve whenever breeders are working for multiple traits. In this study, a Multi-parent Advanced Generation Inter-Cross (BioMAGIC) population with biotic stress resistance was developed using 8 founders that have multiple resistance to insect pests and diseases. The population was subjected for initial screening to blast, rice tungro virus (RTV), brown plant hopper (BPH), green leaf hopper (GLH) and two races of bacterial blight (PXO 61 and PXO 86). Results showed that out of 684 lines, 50% of the lines scored resistant to blast, 76% to different races of BLB such as PXO61, 29% to PXO 86, 28% to GLH, 14% to BPH and 2% to RTV. Fifty two lines with multiple disease resistance were sequenced at 10X depth using Illumina (HiSeq X-Ten). These lines were found to have known genes/QTL for BPH3, BPH17, Xa4, Xa7, xa13, Xa21, Pita and Pi54. For a better understanding of the extent of adaptation of this highly recombined population, 19 genotypes were tested in 3 locations (IRRI, Iloilo and Bukidnon) during 2018WS in the Philippines. Individual and combined analysis of variance revealed significant genotypic effects and genotype and environmental (GxE) interactions for grain yield. Among the lines, IR116262:26-B24-9-10-1 was most stable for grain yield across locations. This line outperformed inbred checks and all the founders and showed resistant reaction of GLH, PXO61, PXO86, blast and has genes/QTLs for Xa4, Xa7 and Pita. In addition to offering disease resistance, BioMAGIC lines will serve as useful donors for varietal development of economically important biotic traits and precisely identifying QTLs for multiple traits.