Saturation of barley chromosomes with transposons to target malting quality traits

大麦是酿造麦芽和啤酒的关键原料。麦芽是由发芽的大麦生产的，用来制作酒精饮料。酿酒公司是大麦芽的主要消费者。麦芽品质是由麦芽提取物百分比、籽粒总蛋白、麦汁蛋白、ß-葡聚糖和籽粒饱满度、a-淀粉酶活性、籽粒重和膨松力等性状组成的。麦芽品质是一种经济上重要的表型，但遗传上很复杂。麦芽品质的遗传改良受其数量性质和低遗传力的制约。对这一性状进行了一系列的遗传剖析，并在大麦遗传图谱上定位了单个数量性状位点（QTL）。位于染色体4H短臂上的QTL2是一个主要的QTL复合物，它影响着几个麦芽品质参数。我们正在用转座子（通常称为“跳跃基因”）饱和麦芽品质QTL区域，以促进QTL2中与麦芽相关的基因的鉴定和表征。这种用转座子进行饱和诱变的努力将有助于更好地理解麦芽品质性状和显示数量变异的候选基因。该QTL中候选基因的鉴定将为大麦育种提供功能标记。

Barley is a key ingredient in malting and brewing. Malt, produced from germinating barley is used for making alcoholic beverages. Brewing companies are the main consumers for barley malt. Malting quality is composed of a number of traits including percentage of malt extract, total grain protein, wort protein, ß-glucan and kernel plumpness, a-amylase activity, kernel weight and diastatic power. Malting quality is an economically important phenotype but genetically complex. Genetic improvement of malting quality is impaired by its quantitative nature and low heritability. A series of efforts have been undertaken to genetically dissect this trait and to localize individual quantitative trait loci (QTL) on the genetic map of barley. One major QTL complex, QTL2 mapped on the short arm of chromosome 4H, affects several malting quality parameters. We are saturating malting-quality QTL regions with transposons, commonly known as "jumping genes" to facilitate identification and characterization of genes associated with malting in the QTL2. This effort of saturation mutagenesis with transposons will lead to a better understanding of malting quality traits and candidate genes that display quantitative variation. Identification of the candidate genes harboured in this QTL will allow development of functional markers for breeding of malting barley.