小麦显性矮秆基因Rht_3理想株高突变体的基因型检测  

Genotyping of Wheat Dominant Dwarfing Gene (Rht_3) in Dwarfing Mutants with Ideal Plant Height

作　　者：傅大雄[1] 余东[2] 阮仁武[1] 罗明华[2] 方宣钧[2] 

机构地区：[1]西南大学农学与生物科技学院,重庆400716 [2]海南省热带农业资源开发利用研究所,三亚572025

出　　处：《分子植物育种》2007年第1期84-90,共7页Molecular Plant Breeding

基　　金：国家自然科学基金项目(30370875);重庆市科委小麦遗传资源创新及应用研究项目资助。

摘　　要：本研究采用4BS染色体携带Rht3基因的小麦显性矮源“矮苏3”（55-60cm），经辐射与化学诱变，获得了一系列株高在70-85cm、具小麦育种理想株高的突变体。采用形态标记、生化标记及分子标记对上述理想株高突变体进行了基因型检测。经成熟种子萌发试验的生化标记检测表明，理想株高突变体仍具有显性矮秆基因Rht3成熟种子α-淀粉酶活性低而抗穗萌的特性。经采用位于4BS染色体上的“易组太谷核不育基因MN2（4BS）”作为形态标记基因来定位理想株高突变体携带的半显性矮秆基因，证实了理想株高突变体携带的半显性矮秆基因与MN2（4BS）连锁、因而与Rht3基因同位于普通小麦4B染色体上。基于通常认为Rht3与隐性矮秆基因Rht。同为4BS染色体上的复等位基因，经采用Ellis等开发的“perfect marker”SSR特异引物的分子标记检测，在矮苏3及其理想株高突变体上同时扩增出了与Rht-Blb相同的237bp的特征带。以上3种类型的基因标记检测的结果，均有利于说明矮苏3的理想株高突变体携带Rht3突变衍生的复等位基因，因其具理想株高而又抗穗萌，可望作为半显性创新矮源用于高度集约化的小麦“分子设计育种”，以克服小麦育种目前局限于使用隐性矮源的局面，实现自“绿色革命”以来小麦育种矮源的升级换代。A set of mutants 70-85 cm tall, i.e. the ideal plant height for wheat breeding, were obtained through irradiation and chemical mutagenesis of the dominant dwarf germplasm, Aisu 3, which carries the Rht3 gene on its chromosome 4BS and is typically 55-60 cm in height. In the present study, morphological, biochemical and molecular markers were used to identify the genotypes of these mutants with ideal plant height. In a test of the germination of their mature seeds with biochemical markers, these mutants （with ideal plant height） were shown to maintain the same low a-amylase activity and high pre-harvest sprouting resistance as the mature seeds carrying the dominant dwarfing gene Rht3. When an intergenomically translocated line with Taigu genie sterility gene （4BS） on chromosome 4BS was used as the morphological marker to locate the semi-dominant dwarfing gene carried by the mutants with ideal plant height, the results confirmed that its semi-dominant dwarfing gene was genetically linked with MS2 （4BS） and was, therefore, co-located on chromosome 4B of common wheat （Triticum aestivum） with the Rht3 gene. Based on the widely held assumption that Rht3 and the recessive dwarfing gene Rhtl may be multiple alleles on chromosome 4BS, the ＂perfect maker＂ SSR-specific primers developed by Ellis et al. were adopted to identify the genotypes of the tested mutants. The characteristic fragment, Rht-Blb, 237 bp in length was amplified in both Aisu 3 and its mutants （with ideal plant height）. The results of all the three genotyping tests mentioned above help to demonstrate that the mutants （with ideal plant height） derived from Aisu 3 carry multi-allele（s） mutagenically originated from Rht3. As they are of ideal plant height and resistant to pre-harvest sprouting, they should be novel dominant dwarfing germplasm resources, which could facilitate wheat breeding by molecular design, overcome the limitation of only using recessive dwarf germplasms in wheat breeding programs and realize an upgrading of

关 键 词：小麦 显性矮秆基因 复等位基因 Rhh3 矮化育种 

分 类 号：S512.1[农业科学—作物学]