DNA marker characterization for allele mining of blast and bacterial leaf blight resistant genes and evaluation for grain yield
AbstractLandraces of rice were evaluated for blast and bacterial leaf blight (BLB) resistance, via tightly linked SSR markers and by phenotyping for flowering time, maturity and grain yield. Correlation between flowering maturity and grain yield was carried out using 162 local landraces and traditional rice cultivars. Days for 50% flowering ranged from 59 to 157 days, maturity from 93 to 192 days and seed yield per plant ranged from 0.24 to 33.3 g. Strong association was observed between flowering time and maturity time. Marker RG64 linked to Pi-2, a major dominant blast resistance gene on Chromosome 6 and marker pTA248 on Chromosome 11 linked to Xa21, a resistant gene to bacterial leaf blight were used to detect the presence of resistant alleles. Three different types of bands of 1 kb carrying Xa21 resistant allele and two susceptible alleles of 700 and 750 bp were amplified using pTA248. 14 rice genotypes were resistant for BLB, 46 genotypes showed susceptible banding pattern, and 87 genotypes were in heterozygous condition for resistance. 28 genotypes carried resistant alleles for both blast and bacterial leaf from among them Gowri Sanna, Ponni, Antharsali and Doddabyranellu were popularly preferred by the farmers. These can serve as donor lines for transferring of both resistances simultaneously.
Keywords: Landraces, blast, bacterial leaf blight, grain yield, DNA markers
African Journal of Biotechnology Vol. 12(18), pp. 2331-2340