title: Identification and characterization of the erect-pose panicle gene EP conferring high grain yield in rice (Oryza sativa L.).
abstract: The breeding of japonica varieties with erect-pose panicle (EP) has recently progressed in the northern part of China, because these varieties exhibit a far higher grain yield than the varieties with normal-pose panicle (NP). A genetic analysis using the F(2) population from the cross between Liaojing5, the first japonica EP variety in China, and the Japanese japonica NP variety Toyonishiki revealed that EP is governed by a single dominant gene EP. Based on previous studies, map-based cloning of EP locus was conducted using Liaojing5, Toyonishiki, their F(2) population, and a pair of near-isogenic lines for EP locus (ZF14 and WF14) derived from the cross between the two varieties; consequently, the STS marker H90 was found to completely cosegregate with panicle pose. The H90 is located in the coding sequence AK101247 in the database, and the AK101247 of Liaojing5 has a 12 bp sequence in exon 5 replaced with a 637 bp sequence of its wild type allele. It was therefore considered that the AK101247 encodes the protein of the wild type allele at EP locus, and that the sequence substitution in exon 5 of Liaojing5 is crucial for expression of the EP phenotype. The effects of EP gene on agronomic traits were investigated using two pairs of near-isogenic lines (ZF6 vs. WF6 and ZF14 vs. WF14) derived from the cross between the two varieties. Experimental results showed that EP gene markedly enhanced grain yield, chiefly by increasing number of secondary branches and number of grains on the secondary branch. EP gene also produced a remarkable increase in grain density.
authors.affiliation: Key Laboratory of Crop Physiology, Ecology, Genetics and Breeding, Ministry of Agriculture/Key Laboratory of Northern Japonica Rice Breeding of Liaoning, Shenyang Agricultural University, Shenyang, China.
authors.forename: Jiayu
authors.initials: J
authors.lastname: Wang
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nakazaki
authors.forename: Shuqian
authors.initials: S
authors.lastname: Chen
authors.forename: Wenfu
authors.initials: W
authors.lastname: Chen
authors.forename: Hiroki
authors.initials: H
authors.lastname: Saito
authors.forename: Takuji
authors.initials: T
authors.lastname: Tsukiyama
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Okumoto
authors.forename: Zhenjin
authors.initials: Z
authors.lastname: Xu
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Tanisaka
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D018556:Crops, Agricultural / Q000235:genetics* / Q000254:growth & development; D017343:Genes, Plant; D005838:Genotype; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D018514:Plant Structures / Q000033:anatomy & histology / Q000235:genetics*; D011110:Polymorphism, Genetic; D011897:Random Allocation