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【目的】对2个新的水稻叶色突变体进行形态结构与遗传分析,并且初步定位这2个突变基因。【方法】在水稻育种材料中分别发现了一株白色条纹叶突变体和一株黄叶突变体,经多代自交已形成稳定的突变系。对突变体的主要形态特征与叶绿素组分等进行分析,观察叶绿体的超微结构,并以这2个突变系杂交产生的F2群体作为定位群体,应用SSR标记对突变基因进行初定位。【结果】与其野生型相比,白色条纹叶突变体的单株穗数减少12.86%,生育期延长11.27%,黄色叶突变体的株高降低31.08%,千粒重减少14.55%,生育期延长17.86%,并且2种突变体的叶绿素含量都显著低于其野生型。电镜观察结果表明:2种突变体的类囊体结构异常,与野生型水稻相比,黄色叶突变体的类囊体片层数变少,白色条纹叶中条纹部分的类囊体片层结构几乎消失,正常绿色部分的类囊体结构没有变化。遗传分析表明:这2种突变性状均受1对隐性核基因控制,位于不同染色体上,将突变基因暂时命名为st9(t)(stripe)、chl12(t)(chlorophyll-deficit)。将st9(t)定位到第一染色体短臂最末端,与分子标记RM1331相距9.6cM,且与标记RM3252等共分离;将chl12(t)定位到第三染色体短臂,与分子标记RM411、RM8208之间的遗传距离分别是1.2、5.1cM。【结论】发现了2个叶色突变新基因,为下一步的基因克隆与功能分析奠定了基础。
【Objective】 Morphological structure and genetic analysis of two new rice leaf color mutants were carried out. The two mutant genes were initially located. 【Method】 A white stripe leaf mutant and a yellow leaf mutant were found in rice breeding materials respectively. After several generations of selfing, a stable mutant line was formed. The main morphological characteristics and chlorophyll components of the mutant were analyzed. The ultrastructure of chloroplast was observed. The F2 population generated by the two mutant lines was used as the locating group. SSR markers were used to locate the mutants. 【Result】 Compared with its wild type, the leaf number per plant of white stripe leaf mutant decreased 12.86%, the growth period was 11.27%, the height of yellow leaf mutant was reduced by 31.08%, the grain weight was reduced by 14.55% and the growth period was prolonged by 17.86% , And the chlorophyll contents of the two mutants were significantly lower than their wild type. Electron microscopy results showed that the thylakoid structure of the two mutants was abnormal. Compared with the wild-type rice, the number of thylakoid lamellae of the yellow leaf mutant decreased. The lamellar structure of the thylakoid in the striated part of the white stripe leaf Almost disappeared, the normal green part of the thylakoid structure did not change. Genetic analysis showed that the two mutant traits were controlled by one pair of recessive nuclear genes and located on different chromosomes. The mutant genes were temporarily named as stripe and chl12 (t) (chlorophyll-deficit). The st9 (t) was mapped to the end of the short arm of chromosome 1, separated from the marker RM1331 by 9.6cM and co-segregated with marker RM3252. The chl12 (t) was mapped to the short arm of chromosome 3 with the markers RM411, RM8208 The genetic distance between them is 1.2, 5.1cM respectively. 【Conclusion】 Two new leaf color mutant genes were found, which laid the foundation for the next gene cloning and function analysis.