分子标记技术聚合Wx基因改良水稻早熟不育系品质

Molecular Marker Technology Polymerizes Wx Genes to Improve the Quality of Rice Early-maturing Sterile Lines

改良早熟型两系不育系‘粤早1S’米质特性,为选育适合华南稻区及长江中下游优质早中稻杂交稻组合奠定基础。本研究以携带低直链淀粉基因Wx的两系不育系材料‘RGD-7S’为供体亲本,以早熟型两系不育系‘粤早1S’为轮回亲本进行杂交,开展杂交、回交和自交相结合的系谱选育方法与分子标记辅助选择(MAS)技术,贯穿以不育系鉴定、人工气候箱光温反应鉴定、米质测定与室内米饭蒸煮食味品质鉴定等方法。通过2次回交,12次杂交,8年系谱选育,最终获得农艺性状整齐、不育株率100%、含有Wx基因且直链淀粉(干基)含量降低的两系不育系‘台早1S’,该不育系在广州早造播始历期60 d、晚造播始历期47 d,雄性不育期达140 d以上,不育起点温度为23℃,米质鉴定直链淀粉含量为13.6%。‘台早1S’于2017年获农业部农作物新品种权申请号20173673.7,并成功进行成果转化,2018年9月通过广东省技术鉴定。本研究通过分子标记辅助选择技术与系谱选育相结合的方法,有效地降低了‘粤早1S’直链淀粉含量,改良了米质特性,选育得到农艺性状优良的优质早熟两系不育系‘台早1S’,为配制优质早熟两系不育系杂交稻组合,充实华南和长江中下游稻区中早熟优质两系杂交稻市场提供了良好材料的基础。

The rice quality characteristics of early maturing two-line male sterile line’Yuezao 1S’were improved,which laid a foundation for breeding hybrids rice suitable for South China and early mid-season rice hybrids in the middle and lower reaches of the Yangtze River.In this study,the two-line sterile line’RGD-7S’carrying low amylose gene Wx was used as donor parent,and the early maturing two-line sterile line’Yuezao 1S’was used as the recurrent parent to carry out hybridization.The pedigree breeding and molecular marker-assisted selection(MAS)technology combining hybridization,backcross and selfing were carried out,and the identification of sterile lines,identification of light and temperature response in artificial climate chambers,determination of rice quality and identification of rice cooking taste and eating quality and so on.Thro ugh 2 backcrosses,12 crosses and 8-years pedigree selection,the research finally obtained two-lines sterile lines’Taizao 1S’with uniform agronomic characters,sterile plant rate of 100%,Wx gene and lower amylose content,60 days of early sowing and 47 days of late sowing in Guangzhou,over 140 days of male sterility,23℃of sterile starting point temperature,13.6%of amylose content and moderate hardness.’Taizao 1s’obtained the application No.20173673.7 of new crop variety right from the Ministry of Agriculture in 2017 and successfully transformed the achievements,and passed the technical appraisal of Guangdong Province in September 2018.The combination of molecular marker-assisted selection technology and pedigree breeding effectively improved the rice quality characteristics of’Yuezao 1S’,and selected high-quality ear ly maturing two-line sterile lines’Taizao 1S’with excellent agronomic traits.The two-line sterile-line hybrid rice combination has provided a good basis for enriching the market of middle-early and high-quality two-line hybrid rice in rice areas in southern China and the middle and lower reaches of the Yangtze River.