Received: 13-10-2016 / Accepted: 14-02-2017
The major problem encountered in F1 hybrid seed production using cytoplasmic male sterile (CMS) lines is the incomplete panicle exsertion at a rate of 30-60% depending on genotype. Application of exogenous GA3 is often required to overcome this problem. A recessive mutant gene (eui) that causes elongation of the uppermost internode at heading stage can be used as a genetic approach to GA3. In this study, DNA markers were used to identify and screen rice plants with eui gene in CMS lines and in F2 segregating and BC1F1 population. The results showed that 6 CMS lines, 12A, L1A, L2A, L3A, L4A and L5A contained eui gene. Phenotypic and genotypic analysis of F2 and BC1F1 population confirmed that elongated uppermost internode trait was regulated by a single recessive gene and followed of Mendelian segregation ratio..