水稻叶色白化转绿突变体WGL的遗传分析与基因定位

Genetic analysis and gene mapping of virescent albino leaf mutant WGL in rice

[目的]对水稻叶色白化转淡绿突变体WGL进行遗传分析与基因定位,为水稻叶绿素合成与质体发育的分子机制研究奠定基础。[方法]水稻白化转淡绿突变体WGL与‘日本晴’、‘越光’杂交构建F2群体,取隐性极端个体定位基因WGL。[结果]白化转淡绿叶突变体WGL由甲基磺酸乙酯(EMS)诱变籼稻‘南京11’获得,2叶1心期叶片开始转绿,但叶缘和叶尖仍表现白化。4叶期后,WGL叶色表现为淡绿色。与野生型相比,WGL的株高显著降低,剑叶长、剑叶宽、穗长、有效分蘖、千粒质量等均有不同程度的降低。3叶期和抽穗期光合色素含量测定结果表明:与野生型相比,3叶期WGL的叶绿素a、b和类胡萝卜素含量均显著下降,抽穗期叶绿素b显著下降。遗传分析表明,突变性状受1对隐性核基因控制。利用基因定位群体,将该突变基因定位在第3染色体短臂RM6472与N3-15两个标记之间大约680 kb范围内。[结论]水稻白化转淡绿叶WGL突变性状受1对隐性核基因控制,基因定位在第3染色体短臂上680 kb区间内。WGL的发现对丰富和深入理解水稻叶色形成和调控的机制及丰富特异种质资源具有一定的意义。

[Objectives]The aim is to identify rice virescent albino leaf mutant WGL,localize the target gene and lay the foundation for the study of the molecular mechanism of chlorophyll biosynthesis and plastid development. [Methods]Virescent albino leaf mutant WGL were crossed with‘Nipponbare＇and‘Koshihikari＇to construct F2 population and we selected the recessive extreme individual to localize the gene WGL. [Results]Virescent albino leaf mutant WGL was isolated from an ethylmethylsulfone-induced‘Nanjing 11＇mutant bank.At 2-leaf stage,leaves of WGL began to turn green,but the blade edge and tip still was albino. After 4-leaf stage,the leaf color of WGL was pale green. Compared with wild type,the plant height of WGL decreased significantly. Flag leaf length,leaf width,panicle length,effective tillers and 1 000-grain weight all reduced to varying degrees. 3-leaf stage and heading stage photosynthetic pigment content determination showed that chlorophyll a,chlorophyll b and carotenoid content of WGL at the 3-leaf stage decreased significantly. At the heading stage chlorophyll b decreased significantly. Genetic analysis showed that the virescent albino leaf phenotype was controlled by a single recessive gene. Furthermore,the target gene was finally localized on the short arm of chromosome 3 and positioned between SSR markers RM6472 and N3-15 by using two F2 populations derived from WGL/Nipponbare and WGL/Koshihikari. The physical distance between RM6472 and N3-15 was about 680 kb. [Conclusions]The phenotype of WGL was controlled by a single recessive gene. WGL was localized on the short arm of chromosome 3 within the physical distance about 680 kb. The discovery of WGL has certain significance for the understanding of leaf color formation and regulation mechanism,and the enrichment of rice germplasm resources.