中文摘要：

【目的】探查水稻联乙烯还原酶基因OsDVR（Os03g22780）碱基序列不同突变引起的突变体表型差异,评估该基因作为叶色标记基因的育种应用潜力。【方法】以EMS化学诱变籼稻品种冈46B和粳稻品种日本晴得到的黄绿叶突变体为材料,利用高效液相色谱（HPLC）从中筛选积累联乙烯叶绿素的突变体,对获得的目标突变体进行遗传分析、基因定位及等位性测验,再对突变体的OsDVR进行DNA测序、编码氨基酸序列比对以及叶片光合色素、植株表型和主要农艺性状比较。【结果】从EMS诱变而来的53份黄绿叶突变体中筛选到2个新的积累联乙烯叶绿素的突变体590ys和525ys,其突变性状均由1对隐性核基因控制,突变基因均定位于已报道的824ys突变基因所在的染色体区域内,且经等位性测验证明均与824ys突变基因等位,因此它们都是OsDVR突变体。然而,590ys、525ys和824ys这3个突变体的OsDVR碱基突变位点和数目不同,导致编码蛋白的氨基酸突变位点和数目不同,造成它们在叶绿素含量、叶绿素组成、植株表型以及主要农艺性状和单株产量的极显著差异。其中,525ys突变体叶片淡黄色,植株生长发育、成熟期的主要农艺性状和单株产量所受影响相对较小,其突变基因基本上可满足对导入不育系的叶色标记基因的要求。【结论】水稻OsDVR碱基序列的不同突变可引起突变体表型和单株产量的极显著差异,该基因作为叶色标记基因在水稻遗传育种中可能具有较大的应用潜力。

英文摘要：

[Objective] The present study was aimed at investigating the differences of mutant phenotypes resulting from different mutations in base sequence of rice divinyl reductase gene OsDVR （OsO3g22780）, and evaluating application potential of this gene in rice breeding as a leaf color marker gene. [Method] The yellow-green leaf mutants isolated from Indica rice variety G46B and japonica rice variety Nipponbare via ethyl methanesulfonate mutagenesis were detected using high-performance liquid chromatography （HPLC） to screen the mutants accumulating divinyl chlorophyll. Then genetic analysis, gene mapping and allelism test of the target mutants were performed. Subsequently, DNA sequencing of OsDVR gene in these mutants and alignment of the deduced amino acid sequences of homologous DVR proteins were conducted, and leaf photosynthetic pigments, plant phenotypes and main agronomic traits of the mutants were investigated. [Result] 590ys and 525ys, two novel mutants accumulating divinyl chlorophyll, were obtained by screening 53 yellow-green leaf mutants isolated from ethyl methanesulfonate mutagenesis. Their mutant phenotypes were all controlled by a pair of recessive nuclear gene and moreover, the mutant genes were all mapped on the chromosomal region harbouring the 824ys mutant gene reported. Furthermore, allelism test confirmed that the mutant genes of 590ys and 525ys were allelic to that of 824ys. So 590ys, 525ys and 824ys mutants were all OsDFR mutants. However, mutational sites of OsDVR mutant gene and their encoded protein product in the three mutants were different, which resulted in extremely significantdifferences of chlorophyll contents and compositions, plant phenotypes, main agronomic traits and yields per plant among the three mutants. Among them, 525ys mutant had slight yellow leaves, and its growth and development, main agronomic traits and yield per plant were affected relatively less, indicating that 525ys mutant gene can basically meet the requirements as a leaf color marker gene introduced into r