高直链淀粉玉米的选育概况与发展前景

简要介绍了高直链淀粉玉米的关键基因ae的发现过程以及高直链淀粉玉米的选育状况和我国高直链淀粉玉米育种存在的挑战和今后的发展前景。     

半粒玉米胚乳直链淀粉含量测定方法的研究

淀粉是玉米作为工业原料最主要的产品,其中直链淀粉在工业上用途更为广泛。玉米直链淀粉含量直接影响玉米淀粉品质,也是高直链淀粉玉米选育的重要指标。测定半粒玉米直链淀粉含量对玉米品质育种早代材料的筛选尤为重要。本实验对半粒玉米样品的前处理及其直链淀粉含量的碘比色测定法进行了研究,提出了半粒玉米样品的直链淀粉含量测定方法。该方法简便有效,可以减少早期选种的盲目性,加快育种进程。     

高淀粉玉米的遗传与育种

综述高淀粉玉米在国民经济中的重要意义，基因的遗传修饰作用及育种进展新动向。尤其介绍了生产光解膜的原料高直链淀粉玉米研究的最新动态。     

高直链淀粉玉米和普通玉米子粒发育过程中与淀粉合成相关酶活性的比较

对高直链淀粉玉米和普通玉米子粒发育过程中与淀粉合成相关酶活性的变化动态进行了比较研究。结果表明,高直链淀粉玉米子粒发育过程中,束缚态淀粉合成酶(GBSS)活性高于普通玉米,可溶性淀粉合成酶(SSS)和淀粉分支酶(SBE)活性低于普通玉米。高直链淀粉玉米总淀粉积累量少、直链淀粉比例大是SSS、GBSS和SBE综合作用的结果。     

我国玉米品质育种研究进展

根据近年来我国玉米品质育处工作实际状况,概述了我国优质蛋白玉米、甜玉米、糯玉米、高直链淀粉玉米、高油玉米、优质油玉米及爆裂玉米、青饲玉米和笋玉米等玉米品质有育种的进展,为优质玉米的进一步研究、利用提供参考。     

Ae显性突变体对玉米农艺性状及直链淀粉含量的影响分析

玉米直链淀粉是重要的食品和工业原料,高直链淀粉性状的产生受多种酶和基因-环境等因素的共同影响。玉米ae基因（amylose extender）突变导致子粒中直链淀粉含量增高、子粒表面皱缩、淀粉颗粒呈不规则形状、尺寸不均匀且表面基质蛋白增多,用于玉米育种后获得的品种直链淀粉含量升高,产量显著降低。通过将显性Ae突变体与16份优质玉米自交系杂交,对F₁代植株进行开花期、株型、产量性状调查,分析F₁代子粒总淀粉、直链淀粉的含量。结果表明,Ae突变体与不同的自交系杂交,F₁代直链淀粉含量及产量的变化存在明显差异,与基因型有密切关系,以Ae突变体和W16F41、CA240为亲本杂交,可显著提高直链淀粉含量同时产量变化最小。根据F₁代表现筛选直链淀粉含量提高、产量变化较小的双亲配制杂交种,可加速高直链淀粉玉米新品种培育进程。     

玉米胚乳突变基因ae1和du1的遗传效应

利用玉米ae1和du1隐性纯和突变自交系与普通玉米自交系48-2的杂交F₁、F₂代子粒为研究材料,通过单粒法测定子粒的直链淀粉含量和重量,用于分析玉米胚乳突变基因ae1和du1的遗传效应。结果表明：F₂代中具有ae1或者du1纯和突变的子粒表皮皱缩,重量明显下降,直链淀粉含量显著提高。在ae1与du1的杂交后代中,子粒的单粒重和直链淀粉含量没有显著变化,表明ae1与du1双突变并不能导致直链淀粉含量增加。单突变的ae1和du1群体内各子粒间的直链淀粉含量和重量差异较大,说明遗传背景中存在影响直链淀粉含量的修饰基因,表明在选育高直链淀粉玉米品系时,应当重视遗传背景的选择和修饰基因的累加。采用单粒法技术对分离后代进行直链淀粉含量和重量选择,有利于积累高直链淀粉修饰基因,是选育子粒饱满、高粒重的高直链淀粉玉米自交系的有效方法。     

玉米胚乳突变基因ae1和du1的遗传效应

利用玉米ae1和du1隐性纯和突变自交系与普通玉米自交系48-2的杂交F1、F2代子粒为研究材料,通过单粒法测定子粒的直链淀粉含量和重量,用于分析玉米胚乳突变基因ae1和du1的遗传效应.结果表明:F2代中具有ae1或者du1纯和突变的子粒表皮皱缩,重量明显下降,直链淀粉含量显著提高.在ae1与du1的杂交后代中,子粒的单粒重和直链淀粉含量没有显著变化,表明伽ae1与du1双突变并不能导致直链淀粉含量增加.单突变的ae1和du1群体内各子粒间的直链淀粉含量和重量差异较大,说明遗传背景中存在影响直链淀粉含量的修饰基因,表明在选育高直链淀粉玉米品系时,应当重视遗传背景的选择和修饰基因的累加.采用单粒法技术对分离后代进行直链淀粉含量和重量选择,有利于积累高直链淀粉修饰基因,是选育子粒饱满、高粒重的高直链淀粉玉米自交系的有效方法.     

高淀粉玉米及其开发利用

本文依据淀粉玉米的营养特点,系统地总结了高淀粉玉米在食品、医药等方面的广泛用途,分析了种植高淀粉玉米的经济效益,提出了高淀粉玉米的育种方法,试图推动我国的高淀粉玉米育种工作。     

高淀粉玉米品种的选育与推广

论述了高淀粉玉米的选育历史与现状以及高淀粉玉米育种的策略与目标,通过分析高淀粉玉米杂交种对其亲本淀粉含量的遗传表现,探讨了高淀粉玉米育种及亲本选配的原则、种子资源的创新与改良、杂交种选配的原则,同时提出了高淀粉玉米杂交种的推广应用技术。     

Gelation characteristics of Mesona chinensis polysaccharide-maize starches gels: Influences of KCl and NaCl

An investigation was conducted into the effects of potassium chloride (KCl) and sodium chloride (NaCl) on the gelation properties of maize starch-Mesona chinensis polysaccharide (MCP) gels. Waxy maize starch (WS), normal maize starch (NS), and high amylose maize starch (HS) were used to compare the effects of different amylose contents on the gel properties of maize starch-MCP gels. The results showed that KCl and NaCl have similar effects on the gelation, rheological, and structural properties of maize starch-MCP gels. The addition of KCl and NaCl increased the pasting viscosity, breakdown values, setback values, dynamic modulus, and apparent viscosity of maize starch-MCP gels, especially for HS-MCP gels. LF-NMR (Low-field nuclear magnetic resonance) showed that salts reduced bound water content while increasing the free water content of maize starch-MCP gels. CLSM (Confocal laser scanning microscopy) results also indicated that salt can restrict the expansion and maintain the integrity of starch granules, especially for WS-MCP gels.     

爆裂玉米爆裂性状的遗传和相关分析

以9个爆裂玉米自交系,采用完全双列杂交,对36个组合F1的5个性状进行了遗传力、基因效应及其相关分析.结果表明,选育膨胀倍数和爆花率均高的自交系和组合是可行的;爆花率与总淀粉、直链淀粉呈显著的负相关关系;膨胀倍数与直链淀粉呈不显著的负相关关系;直链淀粉与总淀粉呈不显著的负相关关系.     

水稻杂交后代灌浆成熟期籽粒淀粉合成关键酶和谷氨酰胺合成酶活性变化的初步研究

 以东农423和藤系180为试材,籽粒直链淀粉和蛋白质含量为选择指标,通过逐代的定向选择形成了遗传背景相近且直链淀粉和蛋白质含量有显著差异的杂种后代,并对水稻灌浆成熟过程中籽粒ADPG焦磷酸化酶、可溶性淀粉合酶、淀粉分支酶、谷氨酰胺合成酶活性变化进行了初步研究。高直链淀粉含量杂交后代的籽粒ADPG焦磷酸化酶、可溶性淀粉合酶、淀粉分支酶活性峰值显著或极显著高于低直链淀粉含量后代,而且在籽粒灌浆前期蛋白质含量高的后代籽粒谷氨酰胺合成酶活性显著或极显著高于蛋白质含量低的后代。因此,通过直链淀粉和蛋白质含量的连续定向选择可以显著提高或降低灌浆过程中的籽粒碳氮代谢关键酶活性。     

Thermal dissolution of maize starches in aqueous medium

Starches are insoluble in neutral water at room temperature. However, if they are heated beyond the boiling point of water in a closed container, they eventually dissolve. The dissolution profile depends on the type of starch. The dissolution processes of maize starches were monitored in real time by measuring the transmittance of starch dispersion/solution while it was heated. It was found that the dissolution of starches in water results from the degradation of the two components of starches, amylopectin and amylose. Starches from both normal maize and waxy maize were fully dissolved in water when their aqueous solution was heated to approximately 174 °C. Upon cooling to room temperature, amylopectin remained in a solubilized state while amylose molecules were retrograded. For starch solutions that have been heated to higher than 191 °C, the color turned brown and the retrogradation of amylose was not observed.     

Comparison of Various Processes for Making Maize Pasta

Maize pasta was produced using various heat treatment such as drum-drying, extrusion-cooking, pasting and steaming. Cooking quality of pasta products were compared and discussed on the basis of starch physico-chemical properties. The best products were obtained by using drum-drying or pasting, whereas the worst product was obtained using extrusion-cooked maize starch. This was interpreted in terms of starchy component degradation and amylose retrogradation ability. The treatment of fresh pasta at high temperature (95°C) with high relative humidity (95%) improved pasta quality: after 1 h under these conditions, cooking losses were decreased by 9%. Addition of monoglycerides also significantly improved pasta cooking quality by making complexes with amylose during pasta cooking. In contrast, cold storage promoted amylopectin retrogradation and scarcely improved maize pasta quality.     

Effect of process conditions and amylose/amylopectin ratio on the pasting behavior of maize starch: A modeling approach

The effects of different process conditions on the pasting behavior of the 14%, w/w suspensions of high amylose, waxy and normal maize starches at mixing speeds of 50, 160 and 250 rpm with the heating rates of 2.5, 5 and 10 °C/min were investigated. In addition, the impact of the starch mixture with an amylose-amylopectin ratio of 0–70% at 160 rpm and a heating rate of 5 °C/min on the pasting parameters was studied. According to the results, when stirring speed decreased from 250 rpm to 50 rpm, the peak viscosity dramatically increased. Furthermore, both heating and stirring rates significantly affected the pasting properties (p < 0.05). The amylose content of maize starch had a negative correlation with peak viscosity, trough viscosity, breakdown viscosity, final viscosity, and setback viscosity. Besides, syneresis values decreased as amylose content decreased from 70% to 0%. According to the kinetic modelling of pasting curves, starch coefficients were found to be higher than 1 for all starches, indicating that the penetration of water into starch granules increased granule swelling rate. The findings of the present study confirmed that both process conditions and amylose/amylopectin ratio can be optimized without necessity of starch modification to obtain the products with the desired quality.     

Changes in Activities of Key Enzymes for Starch Synthesis and Glutamine Synthetase in Grains of Progenies from a Rice Cross During Grain Filling

The progenies differed in amylose and protein contents in grains, which derived from a rice cross, Dongnong 423×Toukei 180, were used to study changes in the activities of ADP-glucose pyrophosphorylase (AGPP), soluble starch synthetase (SSS), starch branching enzyme (SBE) and glutamine synthetase (GS) in rice grains during grain filling. The activities of AGPP, SSS and SBE gradually increased and then declined as a single-peak curve with the process of grain filling in the progenies with high and low amylose contents in grains. The progenies with high amylose content peaked earlier in the AGPP, SSS and SBE activities and had higher AGPP, SSS and SBE activities at the early grain filling stage than those with low amylose content. The GS activity peaked earlier and was higher at the late stage of grain filling in the progenies with high protein content than in those with low protein content. It is suggested that the activities of key enzymes for starch synthesis and glutamine synthetase could be changed in oriented breeding for amylose and protein contents in grains.