Optimising wheat grain shape for improved processing quality

该计划旨在优化小麦和大麦的最终用户品质特征。碾磨产量取决于籽粒的大小和形状以及籽粒中胚乳与其他组织的比例。小麦凹陷的腹沟是有效提取白面粉的一个特别障碍，英国磨坊采用新的去皮技术进一步增加了折痕形态的重要性。对于大麦来说，在酿造过程中，短而肥的籽粒有助于水分的吸收和淀粉的快速动员。我们将使用正向和反向遗传学方法结合模型系统中种子发育的知识来提高我们对籽粒大小和形状的理解。该计划涉及目前在英国从事谷物和种子开发研究的主要实验室，以及一个致力于碾磨技术的领导小组，该小组可以评估改变谷物形状对碾磨产量和麦芽质量的好处。我们已经表明，英国小麦品种在籽粒形态上存在差异，并将把我们的分析扩展到更广泛的种质，包括具有圆形籽粒和减少褶皱的T. aestivum sphaerococum。将“球球”表型渗入到英国优质材料中，可以确定对去皮和碾磨产量的影响。研究籽粒形状qtl在不同群体中的分离，以确定连锁标记。我们还将绘制和鉴定可能在大麦中控制类似（球状体）表型的基因。我们在模式物种拟南芥和玉米中的工作是解决参与胚乳细胞增殖和分化的过程和基因。我们假设这些基因的谷物同源物可能是谷物大小和形状的qtl的基础。所选候选基因的表达将在转基因小麦或大麦中通过TILLING进行改变，并与亲本进行籽粒形态和品质性状的比较。

This programme aims to optimise end user quality traits in wheat and barley. Milling yield is dependent on size and shape of grains and on the proportion of endosperm to the other tissues in the grain. The recessed ventral groove of wheat is a particular obstacle to the efficient extraction of the white flour and the adoption of new de-branning technology in UK mills has further increased the importance of crease morphology. For barley, a short, fat grain is desirable to assist water uptake and rapid starch mobilisation during malting. We will use forward and reverse genetics approaches combined with knowledge of seed development in model systems to improve our understanding of grain size and shape. This programme involves the major laboratories presently engaged in research in grain and seed development in the UK, together with a leading group working on milling technology allowing the benefits of altered grain shape to milling yield and malting quality to be assessed. We have shown that UK wheat varieties differ in grain morphology and will extend our analysis to broader germplasm including T. aestivum sphaerococcum which has rounded grains and a reduced crease. Introgression of the 'sphaerococcum' phenotype into elite UK material will allow the effects on de-branning and milling yield to be determined. The segregation of QTLs for grain shape will be studied in different populations to identify linked markers. We will also map and identify genes that may be controlling a similar (globosum) phenotype in barley. Our work in the model species Arabidopsis and maize is resolving the processes and genes that are involved in cell proliferation and differentiation in the endosperm. We hypothesise that cereal orthologues of these genes may underlie QTLs for grain size and shape. The expression of selected candidates will be altered in transgenic wheat or through TILLING in barley and an assessment of grain morphology and quality traits compared to parental lines.