Eurasian Journal of Biosciences


Bacterial leaf blight (BLB) disease, which is caused by Xanthomonas oryzae pv oryzae, is one of the devastating biotic stress in rice that results in yield losses. Cultivation of the resistant rice varieties has been proven as an environment-friendly and effective approach to address this problem. As such, this study developed a high quality and tightly linked marker of Xa7 gene, a resistant gene that controls BLB disease in rice. In this study, the mapping population of MR263 X IRBB7 was generated. The F2 population was used for genotyping purpose, while the F2:3 lines were employed for phenotyping purpose. Both genotyping and phenotyping data were used in bulk segregant analysis to narrow down the Xa7 region. A total 87 SNP markers were developed to genotype the mapping population. Out of 87 SNPs, only 65 SNPs exhibited acceptable call rates, and this was followed the Mendelian ration of F2 population (1:2:1). This study had successfully narrowed down the region of Xa7 from 118.5 kb to 58.5 kb, flanked by SNP_Xa7_14 and SNP_Xa7_31 that composed of 13 SNP markers. The developed SNP markers, which were tightly linked to Xa7 gene, emerge to be greatly significant in marker-assisted breeding activity to introgress BLB resistant gene into susceptible rice varieties. The application of the developed SNP marker is bound to enhance both efficiency and accuracy in the selection. The linkage drag phenomenon may be minimised as well as the marker is highly close to the target gene.


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