Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany.
Theor Appl Genet. 2010 May;120(8):1559-74. doi: 10.1007/s00122-010-1276-y. Epub 2010 Feb 13.
The control of flowering time has important impacts on crop yield. The variation in response to day length (photoperiod) and low temperature (vernalization) has been selected in barley to provide adaptation to different environments and farming practices. As a further step towards unraveling the genetic mechanisms underlying flowering time control in barley, we investigated the allelic variation of ten known or putative photoperiod and vernalization pathway genes between two genotypes, the spring barley elite cultivar 'Scarlett' (Hordeum vulgare ssp. vulgare) and the wild barley accession 'ISR42-8' (Hordeum vulgare ssp. spontaneum). The genes studied are Ppd-H1, VRN-H1, VRN-H2, VRN-H3, HvCO1, HvCO2, HvGI, HvFT2, HvFT3 and HvFT4. 'Scarlett' and 'ISR42-8' are the parents of the BC(2)DH advanced backcross population S42 and a set of wild barley introgression lines (S42ILs). The latter are derived from S42 after backcrossing and marker-assisted selection. The genotypes and phenotypes in S42 and S42ILs were utilized to determine the genetic map location of the candidate genes and to test if these genes may exert quantitative trait locus (QTL) effects on flowering time, yield and yield-related traits in the two populations studied. By sequencing the characteristic regions of the genes and genotyping with diagnostic markers, the contrasting allelic constitutions of four known flowering regulation genes were identified as ppd-H1, Vrn-H1, vrn-H2 and vrn-H3 in 'Scarlett' and as Ppd-H1, vrn-H1, Vrn-H2 and a novel allele of VRN-H3 in 'ISR42-8'. All candidate genes could be placed on a barley simple sequence repeat (SSR) map. Seven candidate genes (Ppd-H1, VRN-H2, VRN-H3, HvGI, HvFT2, HvFT3 and HvFT4) were associated with flowering time QTLs in population S42. Four exotic alleles (Ppd-H1, Vrn-H2, vrn-H3 and HvCO1) possibly exhibited significant effects on flowering time in S42ILs. In both populations, the QTL showing the strongest effect corresponded to Ppd-H1. Here, the exotic allele was associated with a reduction of number of days until flowering by 8.0 and 12.7%, respectively. Our data suggest that Ppd-H1, Vrn-H2 and Vrn-H3 may also exert pleiotropic effects on yield and yield-related traits.
开花时间的控制对作物产量有重要影响。在大麦中，对光周期（光周期）和低温（春化）的反应已经被选择，以提供对不同环境和耕作实践的适应。为了进一步揭示大麦开花时间控制的遗传机制，我们研究了两个基因型（春大麦优良品种“Scarlett”（Hordeum vulgare ssp. vulgare）和野生大麦品系“ISR42-8”（Hordeum vulgare ssp. spontaneum）之间 10 个已知或假定的光周期和春化途径基因的等位变异。研究的基因是 Ppd-H1、VRN-H1、VRN-H2、VRN-H3、HvCO1、HvCO2、HvGI、HvFT2、HvFT3 和 HvFT4。“Scarlett”和“ISR42-8”是 BC(2)DH 先进回交群体 S42 和一组野生大麦导入系（S42ILs）的亲本。后者是 S42 经过回交和标记辅助选择后的产物。S42 和 S42ILs 的基因型和表型被用来确定候选基因的遗传图谱位置，并测试这些基因是否可能对研究的两个群体的开花时间、产量和产量相关性状产生数量性状位点（QTL）效应。通过对基因特征区域进行测序和用诊断标记进行基因分型，确定了四个已知开花调控基因的等位基因组成，即“Scarlett”中的 ppd-H1、Vrn-H1、vrn-H2 和 vrn-H3，以及“ISR42-8”中的 Ppd-H1、vrn-H1、Vrn-H2 和 VRN-H3 的一个新等位基因。所有候选基因都可以定位在大麦简单重复序列（SSR）图谱上。在群体 S42 中，有 7 个候选基因（Ppd-H1、VRN-H2、VRN-H3、HvGI、HvFT2、HvFT3 和 HvFT4）与开花时间 QTL 相关。在 S42ILs 中，四个外来等位基因（Ppd-H1、Vrn-H2、vrn-H3 和 HvCO1）可能对开花时间表现出显著影响。在两个群体中，效应最强的 QTL 对应于 Ppd-H1。在这里，外来等位基因与开花时间减少 8.0%和 12.7%有关。我们的数据表明，Ppd-H1、Vrn-H2 和 Vrn-H3 也可能对产量和产量相关性状表现出多效性效应。
