Role of chromosomes 1 and 6 in the genetic control of agronomical traits in rice

In order to mapping of QTLs related to agronomical traits, an F2:3 population derived from the cross between Shahpasand (indica) and IR28 (indica) was used to mapping agronomic traits in rice. The linkage map constructed by 33 simple sequence repeat (SSR) molecular markers covered a total of about 336 cM rice chromosomes 1 and 6. Mapping population was grown in Gonbad Kavous University. Five QTLs, for biomass (Two QTLs) and harvest index (Three QTLs) were identified. The allele from IR28 parent increased biomass production. The additive effects of all alleles, except the alleles of qHI-1a increased measured traits in the plant. The QTLs related to harvest index were located on chromosomes 1 and 6 where the allele from IR28 at qHI-1b and qHI-6 increased harvest index. Number of filled grains, plant height, and panicle length, number of panicle, grain weight, and panicle weight were mapped. Three QTLs for number of filled grain were detected on chromosome 1(two QTLs) and choromosome 6 (1 QTL). Indeed, three QTLs on chromosomes 1 and 6 for the number of panicles, one QTL for the plant height (chromosome 6), one QTL for the panicle length and grain weight (chromosome 1) were identified. IR28 alleles in qFG-1a, qFG-1b and qFG-6 increased number of filled grains. Among these QTLs, the three major QTLs with very large effects, i.e. qFG-1a for number of filled grain, qLP-6 for panicle length and qWG-1 for grain weight explained 14.33, 12.45 and 11.99% of the total phenotypic variances, respectively. The results reinforced the idea that, new QTLs of this study could play an important role in the developing of rice populations.