【作者】 高冬丽；

【导师】 柴岩；

【作者基本信息】 西北农林科技大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 荞麦是高寒和土地贫瘠地区的主要粮食作物之一,富含其他粮食作物所没有的生物活性成分芦丁,同时蛋白质含量明显高于大米、小麦、玉米等,而且迥异于谷物蛋白,类似于豆类蛋白,这些特性使荞麦具有重要的营养价值和药用价值。目前,对其生物活性成分芦丁和蛋白的研究主要集中于提取方法及营养特性的测定,如何提高其含量,提高加工利用价值成为亟待解决的问题。本研究以甜荞和苦荞品种为材料,采用-聚丙烯酰胺凝胶电泳研究了荞麦蛋白组分亚基特性,分析了籽粒形成过程中类黄酮和蛋白组分含量的变化及其了氮磷配比对其含量的影响,以期为栽培与育种中调节荞麦黄酮和蛋白质组分含量,进而调节营养与加工品质提供理论依据。所得结论如下:1.甜荞籽粒总蛋白及蛋白质各组分的谱带具有丰富的多态性,而苦荞籽粒总蛋白及蛋白组分谱带的多态性有限;荞麦清蛋白主要由低分子量的亚基构成;甜荞球蛋白组分含由中等到低分子量范围的5～12种亚基,苦荞球蛋白主要由8种亚基组成;甜荞谷蛋白主要由分子量在43-66.2kD之间的3～5种亚基组成,苦荞谷蛋白主要由分子量在31～43kD间的2种亚基组成。2.灌浆初期甜荞籽粒类黄酮含量升高,随后其含量下降,但幅度较小,籽粒成熟时类黄酮含量又上升;苦荞籽粒类黄酮含量在灌浆初期含量也较高,随籽粒成熟逐渐下降,后期略有升高。3.甜荞与苦荞的清蛋白和球蛋白随籽粒成熟表现相同的变化趋势,即两个栽培种的清蛋白在初期含量较高,随籽粒灌浆成熟而逐渐下降,球蛋白含量在整个籽粒发育成熟过程中始终最低,在灌浆过程中略有上升趋势;甜荞的醇溶蛋白含量在整个籽粒发育成熟过程中有所下降,但幅度很小,谷蛋白含量较高,随籽粒发育成熟而升高,在后期下降;苦荞的谷蛋白随灌浆成熟经历了低-高-低的趋势,但变化幅度较小,含量由15.20%升高到18.44%,最后下降为11.50%,醇溶蛋白的变化趋势与谷蛋白相同,但其含量均明显低于谷蛋白。4.不同生育时期叶片和茎中类黄酮含量皆随肥力水平上升而下降。高施肥处理对甜荞类黄酮含量的负效应表现为叶片较茎中更为明显,即与茎相比,甜荞叶片中类黄酮含量更易受肥力水平的影响;高肥处理对甜荞叶片的负效应要大于对苦荞叶片类黄酮含量的负效应,同时,与甜荞不同高肥力对苦荞茎中类黄酮含量也表现一定的负效应,但影响不显著。施肥以及所施肥的种类对甜荞籽粒类黄酮含量的影响差异不显著,高肥力水平则对苦荞类黄酮含量具有负效应。此外,由于长期的环境适应,荞麦具有独特的耐贫瘠性,氮肥利用效率不高。因此,施肥并不是提高荞麦类黄酮含量的理想手段。5.同施N相比,施P更容易影响甜荞籽粒各组分蛋白质含量,且各组分对磷素需求量不同,其中球蛋白含量随施磷水平的提高而提高,而施磷量过高则不利于醇溶蛋白的形成。施肥处理更容易影响苦荞籽粒球蛋白和醇溶蛋白含量,对清蛋白含量影响不显著,且适量氮肥和磷肥均有利于提高苦荞籽粒球蛋白和醇溶蛋白的含量。但是,各施肥水平对甜荞和苦荞籽粒谷蛋白含量的影响都不显著。更多还原

【Abstract】 Buckwheat is one of the staples in alpine region and areas with poor soil. Rich in flavonoid which is absent in other food crops, and protein whose content is higher than that of rice, wheat and maize and property is distinctive, buckwheat has important nutritive and medicinal value. At present, researches on flavonoid and protein focus on the extraction methods and nutrition determination, the improvement of contents, furthermore improving its processing and utilization is great urgent.In order to provide foundation for scientific management and production of high quality buckwheat, this study investigated the subunit property of buckwheat protein component, analyzed the dynamics of flavonoid and protein content with seeds maturing, and the effect of ratios of nitrogen and phosphrous on the content. It got the following main conclusions:1. Subunits composition of albumin, globulin and glutamine of common and tartary buckwheat,two cultured species,were determined using SDS-PAGE method. The results showed that high polymorphism was revealed among different common buckwheat cultivars while that among tartary buckwheat was limited. The albumin of buckwheat was composed of subunits with low molecular weight. Common buckwheat globulin was composed of 5-12 subunits from low to middle molecular weight whereas only 8 subunits constituted tartary buckwheat globulin. Common buckwheat glutelin was composed of 3-5 subunits with molecular weight ranging within 43-66.2kD. Tartary buckwheat glutelin was composed of 2 subunits whose molecular weight ranged within 31-43kD.2. Flavonoid content of common buckwheat seed was higher in the early grain-filling stage, and slowly decreased before rising at the seed maturing stage; Flavonoid content of tartary buckwheat was also higher in the early grain-filling stage, and gradually decreased. At the maturing stage, the flavonoid content was slightly increased.3. The dynamics of albumin and globulin content of common buckwheat and tartary buckwheat showed similar tendency. Albumin content was higher at the early grain-filling stage, and gradually decreased with seeds maturing; Globulin content was lowest and a negligible uptrend was observed in the grain-filling stage; Prolamin content of common buckwheat was also lower and a slightly downtrend was observed, glutamine content was higher with an increasing trend, but declined at the late stage of grain-filling stage; a tendency of“low, high, low”was observed for glutamine content of tartary buckwheat,which was also applicable to prolamin content.4. Flavonoid content of leaves and stems in development stage decreased with high level of fertilizer. High level of fertilization had a more negative effect on the flavonoid content of common buckwheat leaves than that of stems, a more negative effect on the flavonoid content of common buckwheat leaves than that of tartary buckwheat leaves, and an insignificant negative effect was also observed on the tartary buckwheat stems. In addition, because of tolerance to barren soil for a long time, nitrogen utilization of buckwheat is inefficient; therefore fertilization was not an ideal way for improving flavonoid content.5. Content of protein component of common buckwheat seed was more easily affected by P compared with N, and the demand of P was different, its globulin content was improved with higher level of P, which was not favorable to gliadin accumulation; As for tartary buckwheat, its globulin and gliadin content was more easily affected by fertilization level compared with albumin, moreover, moderate level of nitrogen and phosphorus was favorable to the accumulation of globulin and gliadin. However, fertilization level had no significant impact on the glutamine content of common buckwheat and tartary buckwheat.更多还原