Phenotypic characterization of a rice mutant Oryza sativa extraordinary glume 1 (Oseg 1) and its genetic analysis

Abstract

A rice mutant with Japonica 9522 cultivar background Oryza sativa extraordinary glume 1 (Oseg 1) was identified from the M 2 mutant pool mutagenized by 60Co γ-ray. Compared with wild type plants, Oseg 1 developed longer empty glumes and rudimentary glumes. In some Oseg 1 mutants, the number of stamens of flowers was reduced and leaf-like lodicules occurred, and excessive lemma/palea-like organ could be observed in some mutant spikelets. This indicated that OsEG1 could regulate the edevelopment of rudimentary glumes, empty glumes, lemma/palea, lodicules, and stamens. Genetic analysis indicated that Oseg 1 came from a single recessive genetic locus. To clone OsEG1 gene, F 2 population was constructed by a cross between Oseg 1 (Japonica) and Guangluai4 (Indica). Using map-based cloning approach, OsEG1 was mapped on chromosome 4, between INDEL marker OS407 and WHM0466 with genetic distance of 2.0 cm and 1.0 cm, respectively. These results are useful for further cloning and functional analysis of the OsEG1 gene.