一个水稻新型叶色突变体的形态结构与遗传定位

Morphological Structure and Genetic Mapping of a New Leaf Color Mutant in Rice

所用水稻叶色突变体为自然突变,并命名为白淮稻7号,其叶色表型为绿-白-绿,且突变表型只有在移栽等因素引起的机械损伤信号胁迫下才会产生。研究结果表明,叶色转白前,突变体生长态势、叶色、叶绿素a含量和叶绿体超显微结构与野生型差异不大;叶色转白后,突变体总叶绿素、叶绿素a、叶绿素b和类胡萝卜素含量都显著低于野生型和叶色转白前,而叶绿体中的类囊体逐渐降解,基粒片层减少、基粒数量明显减少,且在成熟后突变体叶色黄化、植株变矮小。遗传分析表明,突变性状由1对隐性核基因控制。以该突变体与江西1587的F2群体为定位群体,将突变基因定位于水稻第11染色体分子标记L59.2-7和L64.8-11之间大约740.5kb的区间内。认为该突变基因是一个新的水稻叶色突变基因,暂命名为GWGL。

A natural leaf color mutant gwgl in rice,named Baihuaidao 7,showed a typical phenotype of green-white-green leaf at different stages.The mutant character only arose under signal stress induced by mechanical damage such as transplantation.The leaf color,chlorophyll a content and ultra-structure of chloroplast of the mutant were almost the same with the wild typle at the seedling stage.After the leaf changed white,total chlorophyll,chlorophyll a,chlorophyll b and carotenoid contents of the mutant were evidently decreased,the thylakoid of the mutant were gradually degraded,and the chloroplast grana lamella and grana were decreased.At maturity,the plant of the mutant was etiolated and dwarfed.The genetic analysis indicated that the leaf mutant was controlled by a recessive nuclear gene.Genetic mapping of the mutant gene was conducted by using the F2 mapping population of Baihuaidao 7/Jiangxi 1587.The results suggested that the mutant gene was mapped on rice chromosome 11 between InDel markers L59.2-7 and L64.8-11.The physical distances between the two InDel markers were about 740.5 kb.The mutant gene was considered to be a new leaf gene in rice and designated tentatively as GWGL,which laid a good foundation for fine-mapping,cloning and functional analysis of the mutant genes.