Haplotype Diversity For QTL Associated with Drought tolerance on Chromosome 2 of Rice

In order to investigate the haplotype and allelic diversity of 22 rice (O</em>ryz</em>a sativa </em>L.) genotypes, a factorial experiment was conducted based on RCBD with three replications under normal (without stress) and drought stress (-5 bar) conditions at seedling stage. The 16 primer pairs of SSR markers related to drought tolerance were used for genotyping. The studied traits were included root diameter, root weight, root number, root length, stem weight, stem length, genotypic score and total biomass. Analysis of variance for studied traits showed that there was a significant genetic variation among genotypes. 16 used SSR loci produced 49 alleles. The number of alleles per locus generated by each primer pair varied from 2 to 6 alleles with an average of 3. The polymorphic information content (PIC) values ranged from 0.207 to 0.678 with an average of 0.462. The highest PIC value was found for RM8030 primer (0.678), followed by RM3302 primer (0.651). RM8030 and RM3302 microsatellite markers were useful for discriminating between tolerant and susceptible genotypes and therefore may be useful for marker-assisted selection. 15 haplotypes were identified among these genotypes using Bala haplotype as reference for haplotype diversity. Genotypes of haplotype group 1 including Salari, CT6516-24-3-2, IR77298-14-1-2 and IR50 genotypes can be useful for breeding programs to drought tolerance.