Saturation of barley chromosomes with transposons to target malting quality traits

大麦是酿造和酿造的关键原料。麦芽由发芽的大麦制成，用于酿造酒精饮料。酿造公司是大麦麦芽的主要消费者。麦芽品质由麦芽浸出率、籽粒总蛋白、麦汁蛋白、β-葡聚糖和籽粒饱满度、α-淀粉酶活性、籽粒重量和淀粉力等多个性状组成。麦芽品质是一个重要的经济表型，但遗传复杂。麦芽品质的数量性状和低遗传力阻碍了啤酒品质的遗传改良。人们在大麦遗传图谱上对这一性状进行了一系列的遗传解剖和个体数量性状基因座的定位。位于4H染色体短臂上的一个主要QTL复合体QTL2影响几个麦芽品质参数。我们正在用转座子饱和麦芽品质的QTL区域，通常被称为“跳跃基因”，以便于在QTL2中识别和表征与麦芽有关的基因。这种利用转座子进行饱和突变的努力将有助于更好地了解麦芽品质性状和表现数量变异的候选基因。该QTL中包含的候选基因的鉴定将为啤酒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.