This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in barley.The accuracy of selected quantitative trait loci(QTLs),candi...This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in barley.The accuracy of selected quantitative trait loci(QTLs),candidate genes and suggested markers was assessed in the barley genome cv.Morex.Six common strategies are described for molecular marker development,candidate gene identification and verification,and their possible applications in MAS to improve the grain yield and yield components in barley under drought stress.These strategies are based on the following five principles:(1)Molecular markers are designated as genomic‘tags’,and their‘prediction’is strongly dependent on their distance from a candidate gene on genetic or physical maps;(2)plants react differently under favourable and stressful conditions or depending on their stage of development;(3)each candidate gene must be verified by confirming its expression in the relevant conditions,e.g.,drought;(4)the molecular marker identified must be validated for MAS for tolerance to drought stress and improved grain yield;and(5)the small number of molecular markers realized for MAS in breeding,from among the many studies targeting candidate genes,can be explained by the complex nature of drought stress,and multiple stress-responsive genes in each barley genotype that are expressed differentially depending on many other factors.展开更多
基金supported by Bolashak International Fellowships,Center for International Programs,Ministry of Education and Science,KazakhstanAP14869777 supported by the Ministry of Education and Science,KazakhstanResearch Projects BR10764991 and BR10765000 supported by the Ministry of Agriculture,Kazakhstan。
文摘This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in barley.The accuracy of selected quantitative trait loci(QTLs),candidate genes and suggested markers was assessed in the barley genome cv.Morex.Six common strategies are described for molecular marker development,candidate gene identification and verification,and their possible applications in MAS to improve the grain yield and yield components in barley under drought stress.These strategies are based on the following five principles:(1)Molecular markers are designated as genomic‘tags’,and their‘prediction’is strongly dependent on their distance from a candidate gene on genetic or physical maps;(2)plants react differently under favourable and stressful conditions or depending on their stage of development;(3)each candidate gene must be verified by confirming its expression in the relevant conditions,e.g.,drought;(4)the molecular marker identified must be validated for MAS for tolerance to drought stress and improved grain yield;and(5)the small number of molecular markers realized for MAS in breeding,from among the many studies targeting candidate genes,can be explained by the complex nature of drought stress,and multiple stress-responsive genes in each barley genotype that are expressed differentially depending on many other factors.
文摘【目的】基于水稻MAGIC-Hei(Multi-parent advanced generation inter-cross)群体,在多环境下挖掘镉含量相关新位点/基因,并筛选含有低镉等位基因的优良株系,为选育低镉积累品种提供新的基因和种质资源。【方法】将由8个亲本衍生的MAGIC群体分别于2017、2018、2019和2020年度种植于湖南长沙并开展稻米镉含量表型测试分析。利用GBS(genotyping by sequencing)简化基因组测序获得基因型数据,对稻米镉含量开展全基因组关联分析(genome-wide association analysis,GWAS),发掘QTL位点,解析其遗传机制。【结果】检测到了14个镉积累相关的QTL位点,除了第8染色体之外,其他11条染色体上均有分布。其中6个位点与已报道基因一致,8个为新发现位点。另外,这8个位点分布在第2、4、7、9和12染色体上,均可以在两个及以上环境中检测到,效应较为稳定,可用于下一步精细定位及功能研究。结合基因注释和基因表达分析结果,推测LOC_Os02g37160、LOC_Os02g49560、LOC_Os04g39010和LOC_Os06g46310为镉含量相关位点候选基因,这些基因与重金属转运和积累等功能相关。另外,我们筛选到10个携带有利等位基因的优良株系,可用于低镉积累水稻材料的创制。【结论】发掘了8个水稻镉积累相关性状的QTL位点和低镉优异材料,对于镉积累相关遗传研究和利用分子标记辅助选育低镉积累品种具有一定意义。
