Vol. 21 >B. Research Notes>II. Genetics of morphological traits |
2. | Mapping of the EARLY YELLOWING 1 gene, EYE1 in rice |
M. KUSABA1, S. IIDA2, R. MORITA1 and N. NISHIMURA1 1) Institute of Radiation Breeding, National Institute of Agrobiological Resources, Ohmiya-machi, Naka-gun, Ibaraki, 319-2293 Japan 2) National Agricultural and Bio-oriented Research organization, National Agricultural Research Center for Western Region, Fukuyama, Hiroshima, 721-8514 Japan |
Leaf senescence is a developmentally regulated degeneration process to mobilize nutrients from senescing leaves to other tissues such as developing leaves and seeds. Leaf yellowing, which reflects degradation of chlorophyll, is a good indicator of senescence. In rice, leaf yellowing predominates in the late ripening period. Early-yellowing mutants are thought to be impaired in the regulation of senescence and could be a good material
to analyze senescence. A mutant line, NM67, which was obtained from cv.
'Nihonmasari' treated with ethylenimine, showed early yellowing phenotype
(Iida et al., 1993). Young plants appear almost normal but begin
yellowing from the tips of leaves about four weeks before heading. As
they grow, the yellowing phenotype becomes severer, but they finally develop
fertile panicles. This trait is thought to be conferred by a single recessive
mutation, early yellowing 1 (eye1) (Iida et al.,
1993). Together with the early yellowing phenotype, NM67 have a mutant
phenotype in the seed storage protein profile: low glutelin and high prolamin
content. This trait was conferred by a dominant mutation, Low glutelin
content 1 (Lgc1)(Iida et al., 1993, Kusaba et al.,
2003). Lgc1 is independent from eye1 (Iida et al.,
1993) and no low glutelin phenotype was observed in the eye1 line,
which was selected from the F2 progeny between NM67 and Nihonmasari
(data not shown). |
Vol. 21 >B. Research Notes>II. Genetics of morphological traits |