水稻低温敏感叶色突变体tcd32鉴定与遗传分析

Identification and genetic analysis of low-temperature-sensitive leaf color mutant tcd32 in rice

对粳稻"嘉花1号"经60Coγ诱变处理获得的稳定遗传低温敏感叶色突变体tcd32进行了表型鉴定与遗传分析.在20℃条件下,该突变体表现为白色,光合色素含量明显下降,叶绿体发育不完整,植株最终枯萎死亡;在25℃条件下,三叶期之前幼苗表现为黄色,从第四叶开始逐渐转为黄绿色,光合色素含量也明显下降;而在30℃条件下,其表型与野生型(WT)相比没有明显差异.通过对培矮64S与tcd32杂交的F2代分离群体进行遗传分析,结果表明:该低温敏感叶色突变体性状是受一对隐性核基因(tcd32)控制,利用图位克隆技术将tcd32基因定位在水稻第3染色体上顶端537 kb区域内,发现TCD32是一个新的水稻早期叶绿体发育相关基因.

In this study,the identification and genetic analysis of a stable genetic low-temperature-sensitive leaf color mutant tcd 32 obtained by 60 Co gamma mutagenesis in the japonica rice(Oryza sativa L.)″Jiahua 1″were carried out.Under the condition of 20℃,the tcd 32 mutant showed white leaves and obviously low level of photosynthetic pigments,have not intact chloroplast,eventually mutant plants withered to death.And under the condition of 25℃,the 3-leaf seedlings were yellow,then began to turn yellowish green from the fourth leaves,which also showed lower level of photosynthetic pigments.However,at 30℃,the tcd 32 mutant had no obvious difference from the wild type phenotype.Based on genetic analysis of F 2 segregating population form the cross of Peiai 64S and tcd 32,it was shown that the low-temperature-sensitive mutant trait was controlled by a single recessive gene(tcd 32).Then through map-based cloning,the TCD 32 gene was located to the 537 kb region at the top of chromosome 3,which is a novel gene associated with early chloroplast development in rice.