Genotyping for Blast () Resistance Genes in F Population of Supa Aromatic Rice ( L.).

The ascomycete fungus, or , is known to cause blast disease in more than 80 host plants of the Gramineae family-cereals including rice and grasses. The improvement of the Supa234 rice line (IR97012-27-3-1-1-B, containing gene for aroma) developed at IRRI-ESA Burundi consisted of introgression of R genes ( and ) for blast resistance. The F population obtained via the cross had been screened for blast resistance using inoculation with spore's suspension. The objectives of this study were to assess the presence of and genes for blast resistance and to assess the presence of the gene for aroma in the screened F plants using molecular markers. Genotyping was carried out in 103 F plants which grew to maturity using the KASP genotyping method with SNP markers (snpOS0007, snpOS0006, and snpOS0022) targeting the and genes for blast resistance and the gene for aromatic fragrance. The genotyping results showed that 38 F plants had the gene present in both alleles, 31 F plants with the gene in one allele, and only one plant (3B1) was found with the gene in one allele. The gene for aroma was detected in 27 F plants on both alleles and in 57 F plants on one allele. There were thirteen plants which had both the gene and the gene for aroma, and only one plant (3B1) had a combination of the three genes (, , and ). Seven plants resistant to blast disease (2H2, 2H4, 1G2, 1C12, 1E13, 1B12, and 1C5) with the and genes were found, and only one resistant plant (3B1) had a combination of the three genes , , and which is recommended to be bulked for the development of the Supa aromatic rice variety resistant to blast disease. The plants generated by the best line 3B1 should further be evaluated for grain quality (Supa type) after F generation in the field.