【作者】 齐军仓；

【导师】 张国平；

【作者基本信息】 浙江大学 ， 作物学， 2005， 博士

【摘要】 啤酒大麦(麦芽)的品质指标主要有籽粒蛋白质含量、麦芽浸出率、糖化力、库尔巴哈值、α—氨基氮等。这些品质指标多属数量性状,对环境反应敏感,相互关系错综复杂。β—淀粉酶等一些水解酶类与上述品质性状关系密切。醇溶蛋白作为大麦籽粒主要的储藏蛋白,其组分含量变化对麦芽品质有直接的影响。本文研究了籽粒蛋白质含量、醇溶蛋白组分含量、β—淀粉酶活性以及主要麦芽品质性状的基因型和环境变异及其对氮素营养和主要农艺措施的反应,并分析了醇溶蛋白组分与麦芽品质之间的关系。主要结果如下: 1.氮素营养对籽粒蛋白质和醇溶蛋白组分含量的影响及其与β—淀粉酶活性的关系 采用离体穗培养技术,在7种氮素水平下,选用两个籽粒大小、蛋白质含量有明显差异的品种为材料,研究了氮素、品种以及二者的互作对籽粒蛋白质和醇溶蛋白组分含量及β—淀粉酶活性的影响以及醇溶蛋白组分与β—淀粉酶活性的关系。结果表明:随着培养液中氮素浓度增加,籽粒蛋白质和醇溶蛋白组分含量及β—淀粉酶活性显著增加;籽粒蛋白质含量在氮素水平和品种间差异显著,但品种与氮素之间的互作效应不显著;醇溶蛋白组分含量和β—淀粉酶活性氮素水平及品种间差异显著,且二者的互作效应显著。相关分析表明,β—淀粉酶活性与籽粒蛋白质含量以及三种醇溶蛋白组分含量呈显著的正相关,而B/C醇溶蛋白比率与籽粒蛋白质含量和β—淀粉酶活性呈显著的负相关。 2.氮肥运筹对籽粒蛋白质和醇溶蛋白组分含量的影响及其与β—淀粉酶活性的关系 氮肥用量显著影响籽粒蛋白质含量、B醇溶蛋白和C醇溶蛋白组分含量,而对D醇溶蛋白组分含量的影响不显著;随着氮肥用量增加,籽粒蛋白质含量、B醇溶蛋白和C醇溶蛋白组分含量显著增加,D醇溶蛋白组分含量增加相对较少。品种对籽粒蛋白质含量、C和D醇溶蛋白组分含量的影响要比氮肥用量大,而B醇溶蛋白组分含量的差异主要是由氮肥用量的差异引起的。氮肥用量显著影响千粒重和β—淀粉酶活性,而对产量的影响不显著;随着氮肥用量增加,千粒重和β—淀粉酶活性显著增加,而产量的变化相对较小。品种对千粒重和β—淀粉酶活性的影响要比氮肥用量大。 氮肥施用时期显著影响籽粒蛋白质含量、B醇溶蛋白和C醇溶蛋白组分含量,而对D醇溶蛋白组分含量的影响不显著;与前期施氮相比,后期施用氮肥显著增加籽粒蛋白质和三种醇溶蛋白组分的含量。品种对B、C醇溶蛋白含量的影响要比氮肥施用时期大,而籽粒蛋白质和D醇溶蛋白含量的差异主要是由氮肥施用时更多还原

【Abstract】 Grain protein content, malt extract, diastatic power, kolbach index and alpha-amino nitrogen content are commonly used as the indicators of malting barley. All these characters are controlled by multi-genes and sensitive to environmental factors. Moreover, they are inter-related and dependent. Beta-amylase and other hydrolytic enzymes are closely associated with these parameters. Hordein, being a main storage protein shows a wide variation in its composition and content over the genotypes and environments, posing the great influence on malting quality.The current research was carried out to determine the genotypic and environmental variation of grain protein content, hordein fraction content, beta-amylase activity and some malting quality parameters, as well as the response of these parameters to nitrogen nutrition and major agronomic practices. The correlation between hordein fraction and malting quality was also analyzed. The main results are as follow:1 Protein and hordein content in barley seeds as affected by nitrogen nutrition and their relations to beta-amylase activityTwo barley cultivars differing in grain size and protein content were used to investigate the effects of 7 nitrogen level in culture solution, cultivar and their interaction on grain protein content, hordein content and beta-amylase activity and the relationship between hordein content and beta-amylase activity in vitro spike culture. The results showed that the contents of protein and hordein fraction, and beta-amylase activity in barley grains increased significantly with the nitrogen level in culture solution. Grain protein content was significantly affected by nitrogen treatment and cultivar, and there was no significant interaction between nitrogen treatment and cultivar. Hordein fraction content and beta-amylase activity were significantly affected by nitrogen treatment and cultivar as well as their interaction. The correlation analysis showed that beta-amylase activity was positively correlated with grain protein and hordein fraction contents, and the ratio of hordein B:C was negatively correlated with total protein content and beta-amylase activity.2 Protein, and hordein content in barley seeds as affected by timing ofnitrogen application and their relations to beta-amylase activityGrain protein content, B and C hordein content were dramatically affected by application rate of nitrogen fertilizer, whereas D hordein content was little affected. Grain protein, B and C hordein contents increased significantly with application rate of nitrogen, whereas D hordein content had less increase. The effect of cultivar on grain protein, C and D hordein contents was larger relative to that of nitrogen treatment. The variation of B hordein content was mainly attributed to nitrogen treatment. Grain weight and beta-amylase activity were significantly affected by nitrogen treatment, but grain yield had little changed over three N levels.Grain protein, B and C hordein contents were dramatically affected by application timing of nitrogen fertilizer, whereas D hordein content was little affected. The treatment with N application at late stage had significantly higher protein and hordein fraction contents than the treatment with N application at early growth stage. The effect of cultivar on B and C hordein contents was larger than that of nitrogen application time, whereas the variations of grain protein and D hordein contents were mainly attributed to the application timing of nitrogen. The treatment with N application at late stage had higher beta-amylase activity in comparison with the treatment with N application at early stage.3 Protein and hordein fraction content in barley seeds as affected by sowing date and their relations to malting qualityThe effect of sowing date on grain protein, hordein fraction contents and some malting quality of two-rowed spring barleys was investigated by using ten commercial cultivars with different grain protein content, and relationships among these traits were examined. The results showed that grain protein and B hordein contents increased with the postponed sowing date, whereas sowing date had no significant influence on C and D hordein contents. There were significant differences in grain protein and hordein fraction contents among cultivars. The coefficient of variation of D hordein content was much larger than that of B and C hordein contents, suggesting that D hordein is much affected by environments than the two other hordein fractions. Beta-amylase activity and diastatic powerincreased significantly with postponed sowing date and malt extract was little affected. Grain protein content was positively and negatively correlated to B hordein content and malt extract, respectively. No significant correlation was found between beta-amylase activity, diastatic power and grain protein content. B hordein was negatively correlated with malt extract, whereas no significant correlation was were detected between C hordein, D hordein and malting quality traits.4 The genotypic and environmental variation of hordein fraction content and some malting qualitiesThe differences among cultivars and environments (locations) ingrain protein content, hordein fraction content, beta-amylase activity and its thermal stability as well as some malting quality were studied by using seven two-rowed spring barley cultivars grown at different ecological regions. The result showed that there was a significant difference in these traits among locations and cultivars. Moreover, the interaction between location and cultivar were also significant. The genotypic effect for B hordein, C hordein, diastatic power and kolbach index and alpha-amino nitrogen was larger than environmental effect. By contrast, the environmental effect for grain protein, D hordein, malt extract, beta-amylase activity and thermal stability was larger than genotypic effect.The correlation analysis showed that beta-amylase activity was positively correlated with diastatic power, kolbach index and alpha-amino nitrogen. Malt extract was negatively correlated with alpha-amino nitrogen. The diastatic power was positively correlated with alpha-amino nitrogen and Z?eta-amylase thermal stability. Kolbach index was positively correlated with alpha-amino nitrogen and Z>eta~amylase thermal stability. Grain protein content was positively correlated with beta-amylase activity, diastatic power, alpha-amino nitrogen, and negatively correlated with malt extract. B hordein content was positively correlated with beta-amylase activity, diastatic power and beta-amylase thermal stability, and negatively correlated with malt extract. C hordein content was positively correlated with beta-amylase activity. D hordein content was negatively correlated with kolbach index.更多还原