Morphological Structure and Genetic Mapping of New Leaf-Color Mutant Gene in Rice （Oryza sativa）

• Published in: 水稻科学：英文版 2012, Vol.19 (2), p.79-85
• Main Author: LI Yu-hong WANG Bao-he DAI Zheng-yuan LI Ai-hong LIu Guang-qing Zuo Shi-min ZHANG Hong-xi PAN Xue-biao
• Format: Article
• Language: English
• Subjects: Oryza; 变体基因; 叶绿体超微结构; 叶绿素含量; 形态结构; 水稻植株; 遗传图谱; 颜色转换
• ISSN: 1672-6308; 1876-4762

Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white ~eaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 ~ Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.