title: Comparison of molecular linkage maps and QTLs for morphological traits in two reciprocal backcross populations of rice.
abstract: Comparison of maps and QTLs between populations may provide us with a better understanding of molecular maps and the inheritance of traits. We developed and used two reciprocal BC1F1 populations, IP/DS//IP and IP/DS//DS, for QTL analysis. DS (Dasanbyeo) is a Korean tongil-type cultivar (derived from an indica x japonica cross and similar to indica in its genetic make-up) and IP (Ilpumbyeo) is a Korean japonica cultivar. We constructed two molecular linkage maps corresponding to each backcross population using 196 markers for each map. The length of each chromosome was longer in the IP/DS//IP population than in the IP/DS//DS population, indicating that more recombinants were produced in the IP/DS//IP population. Distorted segregation was observed for 44 and 19 marker loci for the IP/DS//IP and IP/DS//DS populations, respectively; these were mostly skewed in favor of the indica alleles. A total of 36 main effect QTLs (M-QTLs) and 15 digenic epistatic interactions (E-QTLs) were detected for the seven traits investigated. The phenotypic variation explained (PVE) by M-QTLs ranged from 3.4% to 88.2%. Total PVE of the M-QTLs for each trait was significantly higher than that of the E-QTLs. The total number of M-QTLs identified in the IP/DS//IP population was higher than in the IP/DS//DS population. However, the total PVE by the M-QTLs and E-QTLs together for each trait was similar in the two populations, suggesting that the two BC1F1 populations are equally useful for QTL analysis. Maps and QTLs in the two populations were compared. Eleven new QTLs were identified for SN, SF, GL, and GW in this study, and they will be valuable in marker-assisted selection, particularly for improving grain traits in tongil-type varieties.
authors.affiliation: Department of Plant Science, Seoul National University, Seoul 151-921, Korea.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Qiao
authors.forename: Wenzhu
authors.initials: W
authors.lastname: Jiang
authors.forename: Md Lutfor
authors.initials: ML
authors.lastname: Rahman
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Chu
authors.forename: Rihua
authors.initials: R
authors.lastname: Piao
authors.forename: Longzhi
authors.initials: L
authors.lastname: Han
authors.forename: Hee-Jong
authors.initials: HJ
authors.lastname: Koh
mesh_terms: D002874:Chromosome Mapping; D003433:Crosses, Genetic; D008040:Genetic Linkage; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics*; D010641:Phenotype; D040641:Quantitative Trait Loci