Phenotypic Characterization and Genetic mapping of Split-hull Mutant in Rice

Abstract

A split-hull mutant was induced by treating a chemical mutagen, N-methyl-N-nitrosourea (MNU), in the fertilized egg cells of Hwaseonchal. The hull of this split-hull mutant exhibited a gap between lemma and palea during grain filling period. This study was carried out to characterize the split-hull mutant and to construct a genetic map of the gene controlling this split-hull phenotype. In the mutant, hull splitting initiated about 15 days after flowering (DAF). The percentage of split-hull grain in a mutant panicle was about 30 percent. The cause of hull-splitting in mutant was reduced hull size compared to wild type. Genetic segregation ratio of the F2 population derived from the crossing split-hull mutant with Hwaseonchal was fitted to 3:1 ratio (wild type to split-hull type). This indicated that the split-hull trait is controlled by single recessive gene. For detecting the gene controlling the split-hull trait in the mutant, the genetic map was constructed using the F2 population derived from the cross between the split-hull mutant and Milyang 23. The BSA (Bulked segregant analysis) revealed that the gene is linked to two STS markers which are located in chromosome 4.