Genetic analysis and molecular mapping of a novel gene for zebra mutation in rice (Oryza sativa L.)

A novel zebra mutant, zebra-15, derived from the restorer line Jinhui10 (Oryza sativa L. ssp. indica) treated by EMS, displayed a distinctive zebra leaf from seedling stage to jointing stage. Its chlorophyll content decreased (55.4%) and the ratio of Chla/Chlb increased (90.2%) significantly in the yellow part of the zebra-15, compared with the wild type. Net photosynthetic rate and fluorescence kinetic parameters showed that the decrease of chlorophyll content significantly influenced the photosynthetic efficiency of the mutant. Genetic analysis of F2 segregation populations derived from the cross of Xinong1A and zebra-15 indicated that the zebra leaf trait is controlled by a single recessive nuclear gene. Ninety-eight out of four hundred and eighty pairs of SSR markers showed the diversity between the Xinong1A and the zebra-15, their F2 population was then used for gene mapping. Zebra-15 (Z-15) gene was primarily restricted on the short arm of chromosome 5 by 150 F2 recessive individuals, 19.6 cM from marker RM3322 and 6.0 cM from marker RM6082. Thirty-six SSR markers were newly designed in the restricted location, and the Z-15 was finally located between markers nSSR516 and nSSR502 with the physical region 258 kb by using 1,054 F2 recessive individuals.