FTIR and Solid State13C NMR Spectroscopy of Proteins of Wet Cooked and Popped Sorghum and Maize

Fourier transform infrared (FTIR) and solid state¹³C NMR spectroscopic methods were used to investigate changes in maize and sorghum proteins on wet cooking and popping. FTIR spectra indicated that wet cooking led to proteins in two normal sorghums, namely NK 283 (a red hybrid) and KAT 369 (a white variety), two sorghum mutants (P850029 and P851171) and a maize hybrid (PAN 6043) assuming more antiparallel intermolecular β-sheet character, possibly at the expense of some α-helical conformation. Solid state¹³C NMR, using the technique of Cross Polarisation Magic Angle Spinning showed shifts of the protein carbonyl carbon and α-carbon resonances upfield on wet cooking in all samples, also indicating a change in protein secondary structure from α-helical to β-sheet conformation. The extent of secondary structural change on wet cooking seemed to be greater in sorghum than in maize and may have a bearing on the inferior protein digestibility of wet cooked sorghum compared to maize. Popping produced the same secondary structural change as observed for wet cooking in both sorghum and maize. However, the extent of change on popping was less than on wet cooking in sorghum and maize.     

Effects of Popping on the Endosperm Cell Walls of Sorghum and Maize

The structure of the vitreous endosperm of raw and popped grains of popcorn maize and sorghum has been examined by light and scanning electron microscopy. In both cereals, popping produces everted grains consisting of expanded endosperm foam attached to the pericarp and embryo tissue. As previously reported, each bubble of the foam is formed from an individual starch granule inflated by internal steam pressure. Large fissures may contribute significantly to the expansion of the endosperm foam. The cell walls of the vitreous endosperm of both cereals are shattered into small fragments, which separate slightly as the cell contents expand during popping. Despite this, the endosperm cells retain their polygonal outline. Intact cell walls of raw endosperm, wall fragments from popped endosperm foam, and fragments isolated after treatment of the foam withalpha -amylase, were visualised through the autofluorescence of their ferulic acid content. The in vitro digestibility of popped sorghum was unchanged compared to raw sorghum, whereas that of wet-cooked sorghum was greatly reduced. It is suggested that popping-induced wall fragmentation improves the accessibility of the protein and starch reserves of the endosperm to digestive enzymes.     

Evaluation of the Lime-Cooking and Tortilla Making Properties of Quality Protein Maize Hybrids Grown in Mexico

Eleven experimental and three commercial white quality protein maize (QPM) hybrids and two regular endosperm controls were planted at Celaya, Guanajuato, Mexico with the aim of comparing grain physical characteristics, protein quality, lime-cooking and tortilla making properties. All genotypes were planted under irrigation using a density of 80,000 plants/ha and fertilized with 250 kg N-60 P-60 K per hectare. When compared with the controls these QPM genotypes had lower test (77.4 vs. 76.5 kg/hL) and 1,000 kernel weights (327 vs. 307 g), softer endosperm texture (2.5 vs. 1.8 where 1 = soft, 2 intermediate and 3 hard endosperm), lower protein (10.0 vs. 8.0%), higher nixtamal water uptake after 30 min lime-cooking (50.0 vs. 53.1% moisture) and lower pericarp removal scores. The lower thousand-kernel weight and softer endosperm texture observed in the QPM genotypes lowered the optimum lime-cooking time as estimated with regression equations. Most QPM genotypes had higher amounts of lysine, tryptophan and albumins/globulins when compared with the controls. QPMs HEC 424973, HEC 774986 and HEC 734286 had the best grain traits for nixtamalization and therefore the best potential for industrial utilization. The commercial use of these QPM hybrids should benefit Mexicans who depend on tortillas as the main staple.     

能源作物甜高粱和玉米对土壤重金属的富集比较

采用盆栽实验研究不同浓度重金属胁迫下(Cd、Pb、Cr)能源作物甜高粱和玉米不同器官Cd、Pb、Cr含量、富集系数以及冠部累积量。结果表明,Cd胁迫下,甜高粱不同器官Cd含量、富集系数以及冠部累积量(6.28~59.71μg)均高于玉米;Pb胁迫下,玉米不同器官Pb含量、富集系数以及冠部累积量(223.71~652.44μg)均高于甜高粱;随Cr浓度增加,甜高粱和玉米不同器官Cr含量、富集系数以及冠部累积量均呈上升趋势,在Cr胁迫下甜高粱和玉米的生物量较小,冠部Cr累积量小。相比之下,甜高粱适合修复Cd污染土壤,玉米适合修复Pb污染土壤,两种作物均不适合修复Cr污染土壤。     

The Biochemical Basis and Implications of Grain Strength in Sorghum and Maize

This review deals with the biochemical basis and implications of hardness and grain strength in sorghum and maize. Grain hardness affects various aspects of the growth and processing of cereal grain from resistance to fungal infection to cooking quality. It is clear that the prolamins play an important role with the γ-prolamins being the most important. It would appear that these prolamins help shape the protein bodies and form disulphide bonds within themselves or with other proteins. The γ-prolamins form the cement while the α-prolamins are the bricks. Both prolamins are present in greater proportions in hard grains and in the vitreous portion of hard grains. Genetic and environmental effects on the amounts of the different prolamins and on their distributions within the protein body and in different parts of the endosperm also determine grain hardness. Grains that will be hard appear to deposit prolamins and antifungal proteins earlier and in greater amount than do soft grains. The cell wall composition is also different between the two types of grains while there is a higher proportions of amylose in the starch of hard than in that of soft grains. Most of the differences that exist between hard and soft grains also exist between the outer and inner portion of the grain. It is postulated that there might be a master gene controlling the onset of strength in grains by simultaneously altering the levels of various apparently unrelated biochemical events. It is also suggested that solute availability may play an important role in the regulation of expression of genes for hardness-related proteins.     

Effect of Chemical Treatments on Polyphenols and Malt Quality in Sorghum

Tannin-containing sorghums, Chirimaugute and DC-75, and a tannin-free sorghum, SV2, were steeped in water, HCl (0·25 ), formaldehyde (0·017 ) and NaOH (0·075 ) for 8 and 24 h. Germination was carried out for 2 and 5 d. Steeping in NaOH enhanced water uptake of the grains compared with the other treatments. All treatments reduced the polyphenol content of the raw grain. Treatment with NaOH or formaldehyde (HCHO) was more effective than water or HCl. Malt quality was measured in terms of diastatic power (DP). Potential DP, determined after the peptone extraction, indicated higher amylase activity in DC-75 malt than in Chirimaugute and SV2 malt. Available DP, determined after water extraction, was low in malt from the tannin-containing varieties that had been treated with water or HCl. Malting alone was not an effective method of reducing the enzyme inhibitory power of the sorghum tannins. Available DP was markedly improved by the NaOH and HCHO treatments of the tannin-containing varieties. It is concluded that steeping in dilute NaOH is effective in detoxifying high-tannin sorghums, reducing the steeping period and enhancing malt quality. Steeping in NaOH appears to be a safer alternative to HCHO for treatment of high-tannin sorghums in the malting industry and for other food uses.     

荫湿环境对玉米穗位叶面积及其叶绿素含量的影响

采用人工模拟荫湿环境,比较不同基因型玉米在荫湿环境与自然环境条件下穗位叶面积及其叶绿素含量的差异。结果表明,荫湿环境对玉米穗位叶面积、叶绿素及其组分含量具有明显影响,穗位叶面积及其叶绿素a/b值均呈下降趋势,叶绿素相对含量和叶绿素b含量呈明显上升趋势,这些性状的变化基因型间存在显著或极显著差异。用穗位叶面积及其叶绿素含量计算出18个杂交种的综合耐荫湿系数平均值为0.751 1,标准差为0.178 5,变异系数为23.76%;30个自交系的综合耐荫湿系数平均值为0.678 1,标准差为0.155 4,变异系数为22.91%。根据综合耐荫湿系数,采用t检验选出耐荫湿性强的杂交种有8个,自交系有12个;耐荫湿性中的杂交种有5个,自交系有9个;耐荫湿性弱的杂交种有5个,自交系有9个。     

甜高粱新品种新高粱7号选育报告

甜高粱新品种新高粱7号是新疆农业科学院吐鲁番农业科学研究所以本地主栽品种可皮西巴西作母本，从海南岛引进的红粒甜高粱品种海南高粱蔗作父本培育而成的常规种，是新高粱2号的姊妹系。2008年5月经新疆种子管理总站登记、命名。该品种遗传性稳定、生育期短、高产、高糖、早熟、抗丝黑稳病、耐旱耐盐碱，适应性广，产量可达93000kg／hm^2，含糖锤度19％-22％，可用作制燃料乙醇、制糖及青贮饲料。适宜新疆、甘肃、内蒙古、青海、吉林等积温≥2700℃，生育期≥110d的地方种植。     

热带亚热带优质蛋白玉米自交系与温带普通玉米自交系产量配合力研究

采用NCⅡ设计对4个热带亚热带优质蛋白玉米(QPM)自交系和10个温带普通玉米优良自交系配制杂交组合,将组合在云南省3种不同生态环境下进行产量鉴定,以分析这些自交系的配合力,并研究热带亚热带QPM自交系与温带普通玉米自交系间的遗传关系。方差分析表明,地点和组合×地点方差达极显著水平,杂交组合、QPM自交系(P1)和普通玉米自交系(P2)的产量GCA方差以及P1×P2的产量SCA方差达极显著水平。配合力分析结果表明,多数自交系在昆明、保山、曲靖3种不同生态环境下产量GCA、SCA表现差异较大,表明产量GCA、SCA与环境存在互作。产量SCA效应值与产量简单相关分析表明,特殊配合力在产量形成中的作用较小。根据产量SCA相对值,结合自交系系谱来源,分析P1和P2之间遗传关系,结果表明,自交系LX9801、掖107与CML166遗传关系较近;K12、97P-69、97P-64与CML171和CML161遗传关系较近;陕五2134、H84-89-1、K22、云147、90211与CML194遗传关系较近。     

优质、高产、糯质、酿酒高粱泸糯9号的选育与应用

泸糯9号是四川省农业科学院水稻高粱研究所育成的三系糯质高粱杂交种。表现产量高,抗叶斑病,淀粉含量高,出酒率高,再生力强,是酿造浓香型、酱香型和小曲酒的优质原料。适宜我国南方高粱区种植。     

Biochemical Basis of Kernel Milling Characteristics and Endosperm Vitreousness of Maize

Chemical characteristics of 18 normal maize grain samples, having a wide range of physical properties (endosperm vitreousness, kernel friability and milling characteristics), were analysed and related to physical properties. Measurement of damaged starch showed that starch behaved as a passive filler in endosperm. Endosperm protein content and class, as determined from extractability properties and reversed-phase high-performance liquid chromatography, were correlated with kernel physical properties. Endosperm vitreousness and kernel mechanical properties (kernel friability and milling characteristics) were related to different components, however. Vitreousness seems to be linked to the proportion (%) of the two γ-zein fractions, whereas friability increased when α-zein content decreased and when salt extractable protein content increased.     

生物质能源甜高粱新高粱2号选育报告

甜高粱新高粱2号是新疆农业科学院吐鲁番研究所(吐鲁番)以本地主栽品种克皮西巴西为作母本,从海南岛引进的红粒甜高粱品种海南高粱蔗作父本培育而成的常规种。2006年通过新疆科技厅品种审定委员会鉴定。该品种遗传性稳定、高产、高糖、早熟、抗丝黑穗病、耐旱、耐盐碱,适应性广,产量可达93000 kg/hm2,含糖锤度17.4%~19.5%,可用作制燃料乙醇、制糖及青贮饲料。适宜新疆、甘肃、内蒙古、青海、吉林等地种植。     

真菌蛋白的提取及其对玉米病害的抗性诱导

以4种病原真菌为材料,提取其蛋白进行试验,比较了蛋白对玉米大斑病和玉米锈病的抗性作用。结果表明:烟草赤星病的病原菌链格孢属链格孢菌Alternariaalternata(Fries)keissler的提取蛋白对两种病害的抗性都极其显著,很好的应用前景和开发价值。     

不同品种、密度、肥料对甜糯玉米产量的影响研究

根据正交设计原理,对甜糯玉米的产量在品种、密度、肥料配比等三个因素影响下的变化进行了研究,结果表明三因素对甜糯玉米鲜穗产量的影响效果依次为:品种、密度、肥料;在一定范围内,甜糯玉米鲜穗产量随密度的升高而增加;适量施用K肥可以提高产量;并找到了适宜本地的甜糯玉米高产栽培措施的优化组合.     

光质对夏玉米产量和子粒蛋白质含量的影响

以郑单958为试验材料,在夏玉米吐丝后5 d至吐丝后35 d,分别用白色、黑色、红色、黄色、绿色、蓝色的聚乙烯透明食品袋将雌穗完全套住,同时设置不套袋处理(CK),研究灌浆期雌穗照射不同颜色的光对夏玉米产量和子粒蛋白质含量的影响。结果表明,与CK相比,套袋处理显著增加了穗粒数,红袋和蓝袋对穗粒数的增加作用更显著;黑袋抑制粒重的增加,白袋、黄袋、绿袋显著促进粒重的增加;不同颜色的光对穗部性状都有改善作用,绿袋、白袋、红袋、蓝袋分别对穗长、穗粗、穗行数、行粒数的促进作用显著,白袋对子粒败育的抑制作用显著;红袋和蓝袋使子粒的体积分别增加18.8%、27.6%,其余处理抑制了子粒体积的增加;白袋、红袋、黄袋、绿袋、蓝袋增加了子粒的蛋白质含量,黑袋抑制子粒对氮素的吸收和蛋白质的合成。改变灌浆期照射雌穗的光质可以改善穗部性状,减少子粒败育,促进对子粒对氮素的吸收,从而实现产量的增加和品质的改善。     

Molecular Structure of a Low-Amylopectin Starch and Other High-Amylose Maize Starches

The molecular structure of two commercially available high-amylose maize starches, HYLON® V starch and HYLON® VII starch, and of a newly developed low-amylopectin starch (LAPS) was examined. These high-amylose starches give three apparent fractions as determined by gel-permeation chromatography: a high-molecular weight (mol.wt) amylopectin fraction, a low-mol.wt amylose fraction, and an intermediate-mol.wt fraction which contains both linear and branched components. The low-mol.wt amylose fraction increases from 9·4% in HYLON V starch to 17·7% in HYLON VII starch and 26·5% in LAPS, whereas the high-mol.wt amylopectin fraction decreases from 31·1% in HYLON V starch to 13·8% in HYLON VII starch and 2·5% in LAPS. The percentage of linear components in HYLON V starch, HYLON VII starch, and LAPS are 42, 54, and 80%, respectively. High-amylose starches have a large proportion of long chains in their branched fractions compared to waxy-maize and normal-maize starch. Both HYLON VII starch and the LAPS give B plus V-type X-ray diffraction patterns, but the LAPS has even a higher gelatinization temperature, lower swelling power in hot water, and is more resistant to acid digestion. With the lack of amylopectin, amylose accounts for at least part of the double helical structure in the LAPS granules.     

玉米初生根和次生根中铁、锰、铜、锌、钠含量分析

以玉米品种'掖单13'和'丹玉13'为试材,通过大田试验研究供试玉米的初生根和第1层至第9层次生根中的铁、锰、铜、锌和钠等元素的含量.结果表明:玉米根系中铁、锰、铜、锌和钠元素的平均值分别为6469,185,22,14,884mg/kg.玉米初生根中的铁元素与次生根相比其含量较低,锰、铜、锌和钠元素的含量较高,高于各次生根中的含量.玉米同一品种的不同类型根中各元素含量之间存在差异,不同品种相同类型根中的各元素含量存在相关关系.     

不同耕作措施对夏玉米土壤结构和养分的影响

通过2002～2003年夏玉米田间试验研究了不同耕作措施对土壤结构和养分的影响。结果表明:耕作后B2容重减少较多;2003年9月份各个坡度秸秆下B2的0～10cm、11～20cm两土层的平均容重比对照分别降低13.39%和13.41%;2003年9月份各个坡度秸秆下B2的0～10cm土层的平均土壤固相率比对照降低13.38%,平均土壤液相和气相的比例提高了19.72%和10.64%;耕作后B2的土壤养分增加也较多。     

玉米杂交种辽单526选育及栽培技术要点

辽单526玉米杂交种是辽宁省农业科学院玉米研究所以自选系辽7990为母本,外引系丹598为父本组配而成,各级试验及品质分析表明:该品种具有高产、优质、抗病、适应性广、制种产量高等特点。     

玉米杂交种丹玉402号选育及栽培技术要点

丹玉402号是丹东农业科学院以自选系丹299为母本,自选系DH34为父本组配成的玉米单交种,各级试验示范结果表明：该品种具有高产、稳产、抗逆性强、生育期适中、品质优和适应性广等特点。深受农民欢迎。