啤用大麦籽粒多酚组分及含量的基因型差异和表达调控机理

Polyphenol compounds are one of the very important sources of natural antioxidant, which play critical roles both in flavour stability and colloidal stability of beer. However, some of the polyphenol are major components in beer's haze formation. Hereby, polyphenol compounds are of particular interest to brewers and barley breeder. In this project, 200 barley germplasms with significantly different malting quality according to in our previous studies will be used for determining genotypic variation of polyphenol compounds in barley grain and malting. Moreover, two barley genotypes with significant difference in phenolic compounds will be used to investigate the effect of agronomy (level and timing of nitrogen fertilizer) and enviroment factors (temperaure and light) on the dynamics of phenolic compounds accumulation in grains. Triumph and its ABA insensitive mutant TL43 will be used to illustrate the mechanism of polyphenol compounds accumulation regulated by phytohormone, e.g. ABA and BR. Further, a DH population, from a cross between cultivars Yerong and Franklin, will be used to identified QTLs of phenolic compounds accumulation and its nitrogen response factors. In summary, we will determine genotypic and environmental variation of polyphenol compounds accumulation in barley grain and malt, it will benefit the breeding of malting barley.

多酚化合物是一类优质的天然抗氧化剂，在保持啤酒风味和胶体稳定中起着重要作用；但一些多酚成份也是啤酒混浊形成的主要因子。因此多酚及其组分研究日益受啤酒制造商和大麦育种工作者重视。本研究首先利用麦芽品质各异的近200份大麦种质，明确大麦籽粒多酚各组分含量的基因型差异；进而以多酚含量差异显著的大麦基因型为材料，分别在人工气候室和大田中研究主要环境因子（温度和光照）和农艺因素（氮肥用量和运筹等）对大麦籽粒多酚含量及其组分积累动态的影响，明确有益多酚和混浊敏感多酚合成和积累的调控机理。利用Triumph及其ABA不敏感突变体TL43探索多酚各组分合成和积累的激素调控规律。同时利用Yerong 和Franklin 为亲本的DH群体，比较分析籽粒和麦芽多酚各组分积累和氮素调控响应基因的QTL位点。本研究结果将丰富或刷新国内外啤酒大麦品质形成规律的理论，可为优质啤用大麦育种和栽培提供理论依据和技术指导。

大麦是全球第四大谷类作物。多酚是一类优质的天然抗氧化剂，在保持啤酒风味和胶体稳定中起着重要作用，但一些多酚成份也是啤酒混浊形成的主要因子。明确啤用大麦多酚化合物的基因型和环境效应是开展该性状遗传改良和制订优化农艺措施的理论与技术依据。本研究分析测定了栽培大麦和西藏野生大麦籽粒和麦芽多酚各组分含量，结果表明大麦籽粒和麦芽多酚各组分含量具有显著的基因型和环境变异。西藏野生大麦籽粒中两种主要酚酸含量显著高于栽培大麦。全基因组关联分析定位到大麦籽粒和麦芽酚酸组分积累和调控相关基因位点，我们推测在3H染色体的DArT标记bPb-9746和bPb-6347附近可能存在一个与大麦籽粒酚酸含量相关的基因。相关性分析也表明，麦芽酚酸含量对啤用大麦品质影响显著。本研究系统地分析大麦籽粒和麦芽多酚含量及组分积累的基因型差异及其内在的环境调控机理，将丰富或刷新国内外有关啤用大麦品质形成规律的理论，并可为优质啤用大麦育种和栽培提供理论依据与技术指导。