Grain size has a great impact on rice grain yield and is controlled by quantitative trait loci (QTL). Daeribbyeo 1 with big grain is widely used for genetic materials to develop varieties with diverse grain size. This study was conducted to identify genes controlling grain size traits of Daeribbyeo 1. An F2:3 population derived from a cross between two japonica cultivars, Boseogheugchal and Daeribbyeo1, was used to identify QTL controlling grain shape traits. A total of 284 F2 plants were measured for grain shape traits, grain length (GL), grain width (GW), grain thickness (GT), 1,000 grain weight (TGW), and two morphological traits, pericarp color and waxy endosperm. Sixty F3 lines were selected based on the grain shape traits and marker genotypes and evaluated for grain shape traits. For marker analysis, SSR markers tightly linked to five known grain size genes and two QTLs were selected and used for genotyping. A total of 11 QTLs detected on chromosomes 2, 3, 4 and 6 explained phenotypic variation from 3.9% to 59.3%. qTGW2, qGW2 and qGT2 were detected in the same region between RM12811-RM12837 that are tightly linked with GW2 gene. qTGW3 and qGL3 were detected near GS3 gene. To know whether Daeribbyeo 1 has the same mutations in GW2 and GS3 as the various grain-size genotypes, GW2 and GS3 of two parents were sequenced. Daeribbyeo 1 had the same one base (A) deletion at a position 316 as ‘WY3’ in GW2 which results in the loss of function of GW2 gene. Boseogheugchal showed a C-to-A nonsense mutation in the second exon of GS3 gene that increased grain length. Interaction between GW2 and GS3 was not significant indicating that two genes controlled grain-size traits in additive pathway. The results from this study indicate that three QTLs GW2, qGT4 and qGL6 are associated with the grain size variation in Daeribbyeo 1 with GW2 as the major QTL.

서 언
 재료 및 방법
  시험재료 및 재배방법
  농업형질 조사
  DNA추출 및 유전자형 검정
  표현형 마커 유전자형 검정
  통계분석 및 QTL분석
 결과 및 고찰
  양친 및 F2:3 집단의 종자 형태 특성
  유전분석
  염기서열 분석 및 유전자형 검정
  GW2와 GS3 의 상호작용
  대립벼 1호 종자 크기를 조절하는 유전자
 적 요
 REFERENCES

• 심규찬(충남대학교 농업생명과학대학 농학과) | Kyu-Chan Shim
• 강주원(경남 밀양시 점필재로 국립식량과학원) | Ju-Won Kang
• 이현숙(충남대학교 농업생명과학대학 농학과) | Hyun-Sook Lee
• 안상낙(충남대학교 농업생명과학대학 농학과) | Sang-Nag Ahn Corresponding author