IDENTIFICATION OF NEAR-ISOGENIC LINES RESISTANCE TO RICE YELLOW MOTTLE VIRUS

Rice yellow mottle virus (RYMV) is a serious disease in rice production in the lowland and irrigated ecologies. A study was conducted to examine the resistance of rice (Oryza sp.) lines RYMV. One hundred near-isogenic lines (NILs) from BC2F7 population derived from cross combination: Gigante (Oryza indica cv.) x IR64, Gigante x FK28 and Gigante x IR47 were evaluated. Twenty NILs were identified to be resistant to RYMV BF27 isolate from phenotypic screening. Enzyme-Linked-immunosorbent assay (ELISA) test revealed 36 lines to be resistant to RYMV with low virus content. Foreground selection using the gene marker, revealed 22 lines showed introgression of rymv1-2 allele. On the average, 71% of the markers used in the evaluation showed polymorphism. The highest proportion of recurrent parental contribution was obtained from the cross Gigante x IR64; and the lowest from Gigante x IR47. Individuals from Gigante x FK28 had the highest percentage of the donor parent (70%) and Gigante x IR64 had the lowest value but showed the highest genomic proportion of the recurrent parent (57%) was showed by Gigante x IR64.