中文摘要：

【目的】对水稻类病变突变体C23进行遗传分析,并对其突变基因进行分子标记定位。【方法】通过EMS化学诱变获得类病变突变体。对突变体的形态特征、主要农艺性状进行观察,同时进行组织化学分析,对突变性状进行遗传分析,并以C23/浙辐802F2作群体,应用分子标记进行基因定位。【结果】突变体植株三叶期开始在叶片上出现近似圆形淡黄色斑点,随着植株的生长,斑点数量增多,面积逐渐扩大并连成中心枯黄色,边缘黄褐色的病斑,至成熟时病斑几乎遍布整个植株,该类病变发生可能属于程序性细胞死亡过程。与野生型相比,突变体C23的成熟期株高降低,有效分蘖数和每穗着粒数减少,千粒重和结实率降低。遗传分析表明,C23的突变性状由1对隐性核基因控制,该基因位于水稻第12染色体着丝粒附近,SSR标记RM101和InDel标记Ch12-112之间,与这2个标记的遗传距离分别为0.36和0.73cM,并与该区段内的4个InDel标记Ch12-91、Ch12-92、Ch12-95和Ch12-104共分离。【结论】认为C23的突变基因位点与已鉴定的spl1位点接近,但其植株类病变表型与spl1突变体表型有较大差异。

英文摘要：

Objective The objective of this study is to conduct genetic analysis and molecular mapping of lesion mimic mutant C23 in rice.Method A lesion mimic mutant was isolated by chemical mutagen EMS.The phenotypes and main agronomic traits of the mutant were observed.Histochemical analysis was used to detect the cell death type.Genetic mapping of the mutant gene was conducted by using molecular marker and F2 mapping population of C23/Zhefu802.Result The lesion first appeared on leaves as straw-yellow and approximate circular spot at 3-leaf stage.With the growth of the mutant plant,the number of the lesion increased,its area gradually expanded and coalesced into larger lesion with dry yellow center and orangish brown edge.The lesion almost occupied the whole plant till the maturaty stage.The trypan blue staining indicated that the cell death of C23 probably belonged to the programmed cell death.Compared with its wild-type parent,the plant height decreased,the number of productive panicles per plant and the number of spikelets per panicle reduced,1000-grain-weight and seed setting rate dropped.Genetic analysis showed that the lesion mimic character of C23 was controlled by one pair of recessive nuclear genes.This gene is located on rice chromosome 12,nearby centromere,between SSR marker RM101 and InDel marker Ch12-112.The genetic distances from the target gene to two markers were 0.36 and 0.73cM,respectively.At the same time,the mutant gene co-segregated with four InDel markers,Ch12-91,Ch12-92,Ch12-95 and Ch12-104.Conclusion It was considered that the mutant gene of C23 is located on nearby of spl1 gene loci,but the mutant C23 and spl1 have obviously difference in the lesion mimic phenotypes.