利用转基因技术改良小麦品质的研究进展

小麦作为世界丰要粮食来源,其转基因遗传改良受到广泛关注.随着生活水平的提高,人们对面食品各种品质的需求也越来越高,利用转基因技术对小麦进行品质改良成为近几年小麦研究的热点.小麦品质包括加工品质和营养品质,加工品质又包括磨粉品质和食品加工品质.目前的小麦品质改良中,磨粉品质的改良主要通过提高籽粒硬度(grain hardness)基因pin的含量;食品加工品质的改良主要通过提高小麦高分子量谷蛋白业基(high-molecular-weight glutenin subunit,HMW-GS),尤其是1ny10、1Dx5及1Ax1亚基的含量;小麦的营养品质改良主要是提高赖氨酸及铁结合蛋白的含量;面粉白度是衡量面粉品质的重要性状之一,利用转基因技术从遗传因素进行的面粉白度改良主要集中在对多酚氧化酶(polyphenol oxidase,PPO)的抑制上;淀粉品质是小麦品质的一个重要方面,淀粉品质改良的研究主要集中在对支链含量相关淀粉基因的研究上.本文就应用转基因技术对小麦品质在这五个方面的改良进行了概括介绍,并对其中存在的问题进行了探讨.     

天津地区主产虾类多酚氧化酶抑制剂的筛选及应用

多酚氧化酶（PPO）是普遍存在于动植物体内的一种生物酶,它造成食品的褐变,从而严重影响食品的品质。本文以天津地区主产虾类为研究对象,研究了虾的褐变的感官评价与测定多酚氧化酶的活性相结合的方法,分别探讨了抗坏血酸、柠檬酸、植酸等抑制剂对多酚氧化酶的抑制效果,并测得生产贮运过程中使用该抑制剂的浓度与用量。结果表明,在虾中加入0．2％的抗坏血酸时,对PPO抑制效果较好,添加柠檬酸和植酸时效果不明显。     

STS标记在扬麦158×淮麦18F_4群体中的应用及其与PPO活性的关系

小麦籽粒中的多酚氧化酶活性是导致酶促褐变的主要因素.选育低多酚氧化酶活性的品种是改良面制食品外观品质的重要途径之一.本研究利用位于小麦2A和2D染色体上PPO基因分子标记PPO18和STS01,对扬麦158×淮麦18组合的300个F4代分离株系进行PCR扩增,说明不同带型与PPO活性的相关性.结果表明用PP018扩增的300个分离株系中有59个扩增出876 bp(2aaa型)的目标片段,其活性均值为82.01;46个同时扩增出685 bp和876 bp的目标片段(2Aab型)其活性均值为163.41;其余195个扩增出685 bp的目标片段(2Abb型)其活性均值为233.73.方差分析表明三者的PPO活性差异达到极显著水平,其中基因型为2Aaa型的PPO活性值明显低于2Abb型;PPO18在本试验群体中对PPO活性的决定系数为66.61%;用STS01扩增的300个株系中都扩增出了560bp的片段,群体间没有差异.文中说明了两对引物在该群体中的效应及其与PPO活性的关系.     

葡萄多酚含量和多酚氧化酶（PPO）活性与组培苗生根关系的初步研究

研究测定了葡萄属10个种(品种)组培苗的多酚含量和多酚氧化酶(PolyphenolOxidase,PPO)的活性,对其与组培苗的生根指数进行相关性分析,并建立生根指数与多酚含量、多酚氧化酶的多项式回归方程。结果表明:不同种(品种)间多酚含量和PPO活性有显著性差异;多酚含量和PPO活性相关性显著,PPO活性和生根指数不相关,而多酚含量与生根指数呈显著负相关;从回归方程可以看出,PPO活性对生根指数的作用是非线性的,多酚含量对生根指数的作用是线性的,这说明多酚含量对组培苗生根的直接作用很大,PPO活性通过多酚含量间接影响组培苗生根而且直接作用较小。     

陕西省地方小麦品种多酚氧化酶基因等位变异检测及分布

小麦籽粒中多酚氧化酶(polyphenol oxidase,PPO)基因活性与面条等面制品颜色褐变密切相关,降低籽粒PPO活性是小麦品质改良的重要目标.利用PPO基因的功能标记PPO18和PPO29,对115份陕西省地方冬小麦品种(系)进行2A和2D染色体上PPO等位基因印Ppo-A 1a、Ppo-A1b和Ppo-D1b检测,并分析了品种等位变异的分布特点.结果显示:PPO18在等位基因Ppo-A1a(高PPO)和Ppo-A1b(低PPO)中分别扩增685 bp和876 bp的片段,PP029在Ppo-D1b(高PPO)等位基因中扩增490bp的片段.115份品种(系)中Ppo-A1a、Ppo-A1b6和Ppo-D1b等位基因的频率分别为37.39%、60.00%和45.22%.在陕西省所培育和引进的冬小麦品种(系)中,地方当家品种中最低PPO活性基因分布较多,而引进的冬小麦品种中高PPO活性基因分布较多.     

两种遗传背景下小麦Wx近等基因系面粉及面制品色泽研究

为探索不同Wx基因型对面粉及面制品色泽的影响及色泽改良途径,为糯小麦的育种改良提供理论依据,利用‘扬01-2’和‘扬麦17’2种遗传背景下的8种Wx基因型的近等基因系为材料,对8种基因型面粉、面片色泽及色泽主要影响因素多酚氧化酶(PPO)活性进行研究。结果表明,在面粉色泽上,2个背景下8种基因型间总体上无显著差异,其中以aaBBDD和aabbdd 2种基因型面粉色泽略好;在面片色泽及面条感官评价上,2个遗传背景下均以AAbbdd基因型色泽较好,aabbdd基因型色泽较差。面粉多酚氧化酶活性(PPO)检测结果显示,在2个遗传背景下,全缺失型aabbdd均极端高于其它基因型,其原因需深入研究。糯小麦育种需重视对低PPO活性材料的筛选。     

北方冬麦区新育成优质小麦品种面条品质相关性状分析

为了解近年北方冬麦区育成优质小麦品种的品质状况,两年两点统一种植52份优质品种(系)及6份国外代表性品种,测定其磨粉品质、和面仪和混合实验仪特性、淀粉糊化特性及面条品质,并利用5个基因特异性标记分析基因型分布及其对品质性状的影响。结果表明,大部分品种为硬质、中强筋类型,品种间出粉率、面粉a*值、b*值、黄色素含量、PPO活性、和面仪参数、混合实验仪形成时间和稳定时间差异较大。和面仪8 min带宽和混合实验仪稳定时间可作为预测面条品质的重要指标,可分别解释面条总分变异33.3%和34.4%。Ppo-A1a和Ppo-A1b频率为41.4%和58.6%,两种基因型间PPO活性差异显著(P<0.05);Ppo-D1a和Ppo-D1b频率为51.7%和48.3%,但PPO活性差异不显著;Psy-A1a和Psy-A1b频率为81.0%和19.0%,两种基因型间黄色素含量差异显著(P<0.05);1BL/1RS易位和非易位品种频率为13.8%和86.2%,两种基因型间面粉L*值、黄色素含量、和面仪衰落势与8 min带宽、混合实验仪稳定时间等差异显著(P<0.05)。面条品质较好的品种包括Sunzell、石优17、郑麦366、中麦 895、周麦 26、CA1004和石4185。本研究明确了58份小麦品种(系)的品质特征和基因型分布,为优质小麦新品种选育和推广提供了重要信息。     

高白度优质小麦山农优麦3号的选育及其 综合表现和应用分析

随着国际市场的不断开放和我国人民生活水平的提高，人们越来越重视面粉及其制品的安全、营养问题。尽管人们对小麦制粉添加“过氧化苯甲酰”等增白剂的利弊有不同意见，但解决馒头、水饺、面条等中国传统蒸煮类食品既好吃，又好看，又有营养等问题，最好的办法是培育高自然白度的优质小麦新品种。山农优麦3号是国内第一个以面粉白度为育种目标培育的高白度优质小麦品种，面粉自然白度高，可磨制不加任何添加剂的高白度面粉或代替增白剂调剂其它面粉的粉色，具有良好的开发利用前景。     

小麦种质多酚氧化酶的遗传变异及抗穂发芽品种的筛选

为了研究中国小麦品种资源多酚氧化酶(PPO)活性的变异,并对部分主推小麦品种的抗穗发芽能力进行评价和筛选,选用195份小麦种质资源和24份主推小麦品种,采用籽粒法测定了其多酚氧化酶（PPO）的活性。结果表明,供试小麦资源PPO活性表现出较大的变异,变异范围为4.95~13.99 AU/(min?g),变异系数为21.4%,表明小麦PPO活性遗传改良具有很大的潜力;我国主推小麦品种之间的PPO活性差异较大,筛选出‘中麦9’,‘京9428’,‘冀麦38’,‘陕229’,‘宁麦9’,‘川麦47’等PPO活性较低的品种,可以鉴定为抗穗发芽能力较强的品种。     

远红外辐射对萎凋叶氧化酶活性及红茶品质的影响

基于远红外特有的光热效应以及光萎凋在茶叶加工中的优越性,通过单因素试验深入分析不同时长和强度的远红外光萎凋对多酚氧化酶(PPO)活性、过氧化物酶(POD)活性及红茶生化成分和感官品质的影响.结果 表明,萎凋叶中多酚氧化酶(PPO)活性随远红外光强度的上升而上升,随远红外光时间的延长呈现先上升后下降的趋势,POD活性变化...     

河南省小麦馒头品种适宜品质指标的探讨

采用河南省麦区44个主推品种,对河南麦区适宜制作馒头小麦品种的主要品质指标进行了分析。结果表明:河南冬麦区适宜优质馒头的小麦主要品质指标是:面粉蛋白含量11%~12%,湿面筋30%~35.9%,沉淀值23.3~40.3 m L,峰值黏度2200~3700 cp,低谷粘度1400~2400 cp,吸水率57.2%~60.8%,稳定时间2~9.5 min,硬度、直链淀粉和膨胀势中等偏低,面筋指数中等偏高,面粉白度、亮度越高,灰分和PPO活性越低越好。     

小麦面粉色泽(白度)与DArT标记的关联分析

面粉色泽(白度)是评价小麦加工品质的重要指标之一。在4个环境中检测了109份矮孟牛姊妹系及其衍生系的面粉色泽(白度)参数,并利用混合线性模型分析其与覆盖小麦基因组的971个DArT (Diversity Array Technology)标记的关联性。结果显示,17个DArT标记与面粉色泽显著关联,4个标记与白度显著关联(P≤0.001)。标记wPt-1196和wPt-669693在多个环境中与色泽a*和b*关联,且效应值较大。该研究结果为小麦面粉色泽的分子标记辅助选择育种提供了参考信息。     

Variation in quality traits in common wheat as related to Chinese fresh white noodle quality

The variation in grain compositional traits related to Chinese fresh white noodle (CFWN) quality was examined in 25 leading Chinese common wheat cultivars and advanced lines. Large variations were observed in flour yield, flour particle size, protein and ash contents, farinograph and rapid visco-analyzer (RVA) parameters, flour colour components, and polyphenol oxydase (PPO) activity. An improved sensory method was proposed for adequately evaluating CFWN quality of common wheat flour based on methodology used in the Japanese quality scoring system for white salted noodles, but with major modifications in the score weight given to each noodle quality parameter. Large differences in CFWN quality were observed among Chinese wheat cultivars. The correlation coefficients (r) between starch paste breakdown (RVA) and noodle viscoelasticity and smoothness were 0.63 and 0.59, respectively, suggesting that in breeding wheat for high CFWN quality, the starch pasting properties are of major importance. Low ash content was significantly correlated (r = – 0.66) with bright white noodle colour.     

小麦多酚氧化酶抑制和激活效应的研究

通过测定60个小麦品种多酚氧化酶（Polyphenol Oxidase, PPO）分别在铜试剂和CuCl2作用下的酶活性变化情况,分析研究了上述两种试剂对小麦PPO的抑制和激活效应及其受环境、基因型和试剂浓度的影响,结果表明：铜试剂和CuCl2能分别抑制和激活小麦PPO,0.1mM浓度即能起到明显的抑制和激活作用;铜试剂和CuCl2对小麦PPO的抑制和激活作用基本不受环境的影响,但受基因型和试剂浓度的影响,且达极显著水平;CuCl2和铜试剂浓度与小麦PPO活性之间呈对数关系。     

小麦面粉、面条色泽与蛋白质组分的关系

明确面条白度与小麦蛋白质组分含量的关系有助于面条品质的改良。以21个小麦品种制成的面粉及面条为材料，分析了面粉及面条色泽与蛋白质组分含量之间的关系，讨论了蛋白质组分中单体蛋白含量、可溶性谷蛋白含量和不溶性谷蛋白含量对小麦面粉及不同工艺阶段面条色泽的影响。研究结果表明，面粉的颗粒度与面粉及面条的L值呈极     

Wheat quality traits and quality parameters of cooked dry white Chinese noodles

Dry white Chinese noodle (DWCN) is widely consumed in China, and genetic improvement of DWCN quality has become a major objective for Chinese wheat breeding programs. One hundred and four bread wheat cultivars and advanced lines, including 88from major Chinese wheat-producing areas, were sown in two locations for two years. Their DWCN quality, as evaluated by trained panelists, was studied to determine the relationship between wheat quality parameters and DWCN quality attributes. In general, the cultivars and advanced lines used in this study are characterized with acceptable protein content, but accompanied with weak-medium gluten strength and poor extensibility, and substantial variation is observed for all grain and DWCN quality characters. On average, Australia and USA wheat performed better DWCN quality than Chinese wheats. Simple correlation analysis indicated that both grain hardness and Farinograph water absorption were negatively associated with cooked DWCN color, appearance, smoothness, and taste. Flour whiteness and RVA peak viscosity was positively associated with all DWCN parameters, and their correlation coefficients (r) with DWCN score are 0.34 and 0.41, respectively. Their positive contributions to DWCN quality were mostly through improved color, appearance, smoothness, and taste. Farinograph mixing tolerance index (MTI) and softening were negatively associated with all DWCN quality parameters, and their correlation coefficients with DWCN score are –0.50 and–0.54, respectively. Further analysis indicated that association between protein content, Zeleny sedimentation value, Farinograph stability, and Extensograph extensibility, and DWCN score fit quadratic regression model significantly, with R² 0.12, 0.32, 0.22, and 0.20, respectively. The associations between Zeleny sedimentation value and DWCN's appearance and taste also fit quadratic regression model significantly. This suggests that to certain extent, increased protein content and gluten quality contribute positively to DWCN quality, mostly by improving palatability, elasticity, and stickiness. High flour whiteness, medium protein content, medium to strong gluten strength and good extensibility, and high starch peak viscosity are desirable for DWCN quality. Genetic improvement for flour whiteness, protein quality and starch paste viscosity would increase the DWCN quality of Chinese bread wheat cultivars. This revised version was published online in July 2006 with corrections to the Cover Date.     

Suitability of Chinese wheat cultivars for production of northern style Chinese steamed bread

Fifty-six bread wheat cultivars and advanced lines from major Chinese wheat growing regions and 10 Australian cultivars were grown in Anyang located in Yellow and Huai Valleys and Chengdu located in Yangtze region. The genotypes were examined for their suitability to produce northern style Chinese steamed bread (CSB) and used to investigate the association between wheat quality traits and performance of northern style CSB under manual and mechanized processing conditions. Anyang-sown wheat samples showed better grain quality characteristics and CSB quality than the Chengdu-sown materials. These differences were largely due to adverse climatic conditions prevailing in Chengdu that resulted in the deterioration of flour whiteness, Farinograph stability, and starch quality. Therefore, Chengdu was generally unfavorable for producing good quality wheat. However, significant variability among cultivars was observed in Chengdu, and Batavia, Dollar bird, and Tasman from Australia and Jing 411, Xiaoyan6, and Shaan 229 from China showed very good CSB quality under manual conditions, and Hartog, Batavia, Tasman, and Vulcan from Australia, and Jing 411 and Dongfeng 1from China were identified to confer good CSB quality under mechanized conditions. The wide range of CSB quality variations indicates that genetic improvement of CSB quality is possible in both environments. Protein content, gluten strength, and extensibility were positively associated with loaf volume and steamed bread elasticity. The relationship between gluten strength, extensibility, and appearance and stickiness were highly dependent on processing methods, i.e., negatively using a manual method and positively or slightly negatively using a mechanized process. Therefore, wheat quality requirement for CSB depends on CSB processing conditions. Medium protein content and medium-to-strong gluten strength with good extensibility is desirable for mechanized methods, but weak-to-medium gluten type for manual methods. High flour whiteness and RVA peak viscosity was found desirable for CSB quality regardless of the processing method used. Flour whiteness, falling number, and peak viscosity appeared to be more crucial in determining CSB quality in Chengdu, although protein content and Farinograph stability also contributed to appearance, elasticity, and stickiness. This revised version was published online in July 2006 with corrections to the Cover Date.     

高产小麦品种‘济麦22’配粉效应及馒头制作品质研究

为了深入了解‘济麦22’的食品加工特性和配粉技术,更大程度地发挥‘济麦22’的高产潜力价值及为面粉企业更好地利用该品种提供理论依据。将当前大面积推广的小麦品种‘济麦22’面粉按0、20%、40%、60%、80%和100%比例分别与‘济南17’和‘济宁13’面粉混合,形成不同类型的配粉,研究了配粉的面粉颜色、蛋白质特性、面团揉混特性、淀粉RVA糊化特性等变化及馒头品质表现。结果表明,不同类型配粉的品质特性存在差异,‘济麦22’与‘济南17’的2、3号配粉的白度、面片色泽、蛋白质特性和面团揉混特性等均有较好改善,3、4号配粉具有较好的RVA糊化特性,3、4号配粉的馒头品质较好;‘济麦22’与‘济宁13’的4、5号配粉的面粉白度和面片色泽特性较好,3号配粉具有较好的蛋白特性,3、4、5号配粉的面团揉混特性和RVA糊化特性得到一定改善,2、3号配粉的馒头品质较好。这说明添加一定比例的‘济麦22’面粉到‘济南17’或‘济宁13’面粉中可以生产出适合制作优良馒头的面粉。‘济麦22’与‘济南17’面粉的合理搭配不仅可以合理利用有限的‘济南17’优质小麦,更重要的是使‘济麦22’的高产潜力得到更好地发挥,在最大程度上提高‘济麦22’和‘济南17’原粮的经济价值和使用价值。