结实期相对高温对稻米淀粉粘滞性谱及镁、钾含量的影响

选用武育粳3号(粳稻)和扬稻6号(籼稻)两个水稻品种,利用人工气候室在水稻灌浆结实期进行控温试验,设置全结实期相对高温、结实前期相对高温、结实后期相对高温、全结实期适温(对照,日均温23 ℃)对照4个处理,探讨结实期不同时段相对高温(日均温度-30 ℃)对稻米淀粉粘滞性谱和Mg、K等元素含量的影响.结果表明：结实期相对高温使武育粳3号和扬稻6号淀粉粘滞性谱特征值发生改变,其中糊化开始温度、冷胶粘度、回复值和消减值升高,最高粘度、热浆粘度和崩解值下降;结实期相对高温促进了米粉中Mg、K、N含量的提高,特别是K含量的大幅提高,使稻米中Mg/K和Mg/(N·AC·K)明显降低;而2个水稻品种的直链淀粉含量（AC）对相对高温的反应截然相反,武育粳3号的AC降低、扬稻6号的AC升高.全结实期相对高温对稻米淀粉粘滞性谱和Mg、K等元素含量的影响最大,结实前期其次,结实后期的影响较小,开花后20 d内是稻米淀粉粘滞性谱和Mg、K等元素含量受温度影响的关键时期.Mg/K和Mg/(N·AC·K)与淀粉粘滞性谱特征值显著相关,可以作为稻米食味品质评价的参考指标.     

不同栽培模式下紫芝的氨基酸含量测定

通过对不同栽培模式(木屑栽培的紫芝,菌草栽培的紫芝,枝条栽培的紫芝,段木栽培的紫芝)下紫芝中蛋白质、游离氨基酸和水解氨基酸的分析。结果表明,蛋白质含量最高为菌草栽培的紫芝,其含量为18.53%;游离氨基酸总量最高为枝条栽培的紫芝,其含量为0.99%;水解氨基酸总量最高为菌草栽培的紫芝,其含量为12.22%;在水解氨基酸中,4种栽培模式含量最高的都为蛋氨酸,其中木屑袋料栽培的紫芝,枝条栽培的紫芝和段木栽培的紫芝含量都超过5%,其中含量最高为段木栽培的紫芝,其含量为5.42%。     

灌浆期气温与源库强度对稻米品质的影响及其生理分析

利用自然条件下的早、晚季种植作为温度处理,选择米质低、中、优等级的6个水稻品种（组合）作为供试材料,研究了早、晚季种植下的稻米品质、淀粉分支酶活性变化,以及温度处理间的差异.结果表明,在籽粒灌浆初期,高温环境下灌浆充实的籽粒,其稻米的垩白增加、透明度变差、整精米率下降,对出糙率及精米率没有明显影响.与早季种植的稻米相比,晚季种植稻米的胶稠度、整精米率、透明度增加.早、晚季种植对稻米直链淀粉含量、蛋白质含量等没有显著影响.剪叶限源处理显著降低稻米质量,疏粒减库处理显著提高稻米品质.     

稻米赖氨酸快速测定条件的探讨

以氨基酸自动分析仪测定稻米赖氨酸含量为参照标准。在“茚三酮测定赖氨酸含量”(A法)的基础上,对该法中大米蛋白质的提取温度和时间、色温度和时间及茚三酮用量等条件进行了探讨,提出了稻米赖氨酸含量快速测(B法)。提取条件为90℃5分钟,显色条件为90℃20分钟;茚三酮试剂用1 ml。用B法对10个大米样品进行测定,赖氨酸含量与氨基酸分析仪测得的赖含量基本上一致,无显著差异(P>0.05)。     

稻米品质性状对开放式空气二氧化碳浓度增高的响应

利用开放式空气CO2浓度增高(FACE)系统平台。研究大田栽培条件下粳稻武香粳14号稻米品质性状对CO2浓度增高200μmol·mol^-1的响应。结果表明．FACE处理稻谷的出糙率平均比CK高1．4个百分点,整精米率平均比CK低12．3个百分点,较低的供N水平有利于提高FACE条件下的出糙率．较高的供N水平有利于提高FACE条件下的整精米率;FACE处理的稻米垩白略有增加。垩白粒率平均比CK高11．9个百分点,垩白度平均比CK平均高2．8个百分点,较高的供N和供P水平有利于降低FACE条件下垩白大小、垩白粒率和垩白度;FACE处理稻米糊化温度平均比CK平均高0．52℃,胶稠度有提高的趋势,但对稻米直链淀粉含量影响较小,较高的供N和供P水平有利于降低FACE条件下稻米的直链淀粉含量,较低的供N和较高的供P水平有利于降低FACE条件下稻米胶稠度,较低的供N水平有利于降低FACE条件下稻米糊化温度;FACE处理使稻米蛋白质含量比CK平均低0．6个百分点,较低的供N和供P水平有利于降低FACE条件下稻米蛋白质含量。     

导入反义蜡质基因改良水稻稻米的食味品质和营养品质

经PCR、Southern blot和稻米GUS检测,蜡质基因反义片段与gus构成的融合基因已整合到8株水稻基因组中,并能正确表达。通过稻米GUS染色追踪分析获得转反义蜡质基因纯合后代。将转基因植株的稻米送农业部稻米及制品质量监督检验测试中心进行糙米蛋白质含量和直链淀粉含量测定。结果显示：（1）在转反义蜡质基因纯合的超2-10粳稻后代中,大多数单株糙米在直链淀粉含量降低的同时,蛋白质含量有不同程度提高,糙米蛋白质含量和直链淀粉含量呈显著负相关关系;（2）对照糙米直链淀粉平均含量和糙米蛋白质平均含量分别为13.4%和9.5%。在转基因植株中,稻米直链淀粉含量最低的为11.4%,而蛋白质含量也相对最高,为13.5%。本试验结果表明在水稻中导入反义蜡质基因不仅能够降低水稻稻米的直链淀粉含量,还有可能提高水稻稻米的蛋白质含量。     

灌浆期高温对水稻光合特性、内源激素和稻米品质的影响

以2个籼稻品种:温度钝感型品种K30和温度敏感型品种R21为材料,利用人工气候室控温,在水稻灌浆期设置高温(日均温度34.9℃)和适温(日均温度28.0℃)处理,测定不同灌浆时期(5,10,15,20,25d和30d)光合特性、内源激素含量及稻米品质的变化。结果表明,高温增强了K30的光合能力,K30高温处理净光合速率(Pn)在整个灌浆期都明显高于对照;R21在灌浆前期(5、10d和15d)高温处理与适温处理Pn差异不明显,在灌浆后期(20、25d和30d)高温处理Pn下降。高温增加了K30叶片和籽粒脱落酸(ABA)含量;而R21高温处理和适温处理叶片与籽粒ABA含量的对比不明显。高温处理对两个水稻品种叶片和籽粒赤霉素(GA3)与生长素(IAA)含量也有不同程度影响。高温胁迫降低稻米品质,但K30比R21表现出更强的温度钝感特性。     

稻田温室气体减排措施对稻米氨基酸含量的影响

为探索稻田中温室气体减排措施对稻米氨基酸含量的影响,用10个不同方法对双季稻田进行处理,并使用高效液相色谱分别测定了各处理稻田中所产稻米中的16种氨基酸的含量,其中色谱柱为Agilent Zorbax AAA分析柱,柱前衍生使用邻苯二甲醛(OPA)和9-芴甲基氯甲酸酯(FMOC-CL)为衍生试剂。结果发现:1)10个处理中的稻米16种氨基酸种类齐全,施氮肥+添加生物质炭48 t/hm2+间歇灌溉(NPK+HBC+IF)处理中所得氨基酸总量为6520.7 mg/100g,效果最佳;对照组处理(不施加氮肥+无稻草还田+间歇灌溉)所得氨基酸含量4338.0 mg/100g为最低。以对照组处理所得必需氨基酸百分含量36.8%为最高值;无稻草还田+长期淹水(NPK+CF)处理方法所得必需氨基酸百分含量33.1%为最低值。10个处理中16种氨基酸中含量较高的氨基酸均为天冬氨酸、谷氨酸和精氨酸,含量最低的均为甲硫氨酸;2)施氮肥量相同时,长期淹水与间歇灌溉相比,氨基酸总量增加185.1 mg/100g,非必需氨基酸百分含量增加3%,谷氨酸、组氨酸和丝氨酸含量明显升高,但亮氨酸含量显著降低;3)施用氮肥能提高稻米中的氨基酸含量,且随着氮肥使用量的增加,氨基酸含量也随之增加,组氨酸含量增加显著;4)供氮量相同时,添加猪粪使氨基酸总含量升高了286.0 mg/100g,此结果表明,在供氮量相同的情况下,施用猪粪更有利于稻米氨基酸含量的提高;5)灌溉模式相同时,稻草还田配施氮肥对必需氨基酸和氨基酸总量均有提高,天冬氨酸、谷氨酸和组氨酸的含量增加较多,甲硫氨酸含量略有下降;随着稻草还田量的增加,对非必需氨基酸影响较为明显;当稻草半量还田(还田量为3 t/hm2)时,稻米中氨基酸总量增加最多;稻草全量还田+长期淹水(NPK+HRS+CF)与稻草半量还田+间歇灌溉(NPK+LRS+IF)处理中的氨基酸含量基本接近,但必需氨基酸含量前者略高于后者,说明稻草还田与水肥管理对氨基酸含量影响可能存在交互作用;6)添加生物质炭配施氮肥提高了稻米必需氨基酸与非必需氨基酸含量,且随着生物质炭添加量的增加而增加;与稻草还田、添加猪粪处理相比,生物质炭的添加对氨基酸总含量提升的效果最为显著,对稻田实际生产具有指导意义且具有一定的环境效益。     

灌溉方式对黄淮稻区优质粳米品质的影响

为探明不同水深处理对优质稻米的影响,研究了湿润、浅水、深水3种灌溉方式对优质粳稻(圣稻14、圣稻2572、圣稻18)籽粒外观、稻米直链淀粉、蛋白质含量及淀粉RVA谱的影响,分析了稻米品质与理化指标之间的关系.结果表明: 浅水灌溉下籽粒面积、周长、粒长、稻米蛋白质含量显著高于其他灌溉方式,垩白率和垩白度的表现相反;RVA谱的最高黏度和热浆黏度值以湿润灌溉最高,深水灌溉最低,最终黏度值以深水灌溉最低;不同品种RVA谱的崩解值、消减值、回复值及稻米直链淀粉含量对3种灌溉方式的响应存在明显的基因型差异.圣稻14以湿润灌溉的食味品质最好,圣稻18则以深水灌溉最好.相关分析表明,稻米RVA谱特征值与稻米外观指标及蛋白质含量之间存在显著的相关性.回归与通径分析表明,粒型是影响崩解值与消减值的主要因子,而稻米蛋白质与直链淀粉含量是影响回复值的主要因子.     

经大豆DNA溶液处理的水稻后代种子的粗蛋白和氨基酸含量分析初报

以大豆为外源DNA供体,用浸种及幼苗期浇灌法和花粉管通道法直接将大豆总DNA导入受体水稻,经常规栽培获得水稻后代种子。采用微量凯氏定氮法和氨基酸自动分析仪进行水稻后代种子糙米的粗蛋白含量和氨基酸含量的测定。结果显示:三组经大豆DNA溶液处理获得的水稻后代种子糙米粗蛋白平均含量分别为16.42%、16.80%和19.87%,与对照组相比有明显提高,统计分析都达到极显著的差异(P < 0.01);在氨基酸含量测定中,有些材料的总氨基酸(除色氨酸以外)含量高达17.20%、16.86%和16.09%,其中赖氨酸的含量分别为0.60%、0.60%和0.57%,与对照组相比也有明显提高,统计分析差异也都达到极显著水平(P < 0.01)。本试验结果充分说明,利用大豆总DNA的导入方法有可能达到迅速有效地提高稻米蛋白质及赖氨酸含量的目的。     

Physicochemical properties of giant embryo rice Seonong 17 and Keunnunjami

This study was carried out to determine the physicochemical properties of giant embryo rice “Seonong 17” and “Keunnunjami” in comparison with the normal embryo rice. Scanning electron microscopy revealed that Seonong 17 and Keunnunjami have larger embryo and that starch granules from Keunnunjami were more tightly packed with smaller air spaces between granules. Seonong 17 exhibited the lowest amylose content. Keunnunjami showed the highest protein content, pasting temperature, peak and breakdown viscosities, and gelatinization temperature and enthalpy. Both giant embryo rice samples contained significantly higher amounts of essential amino acids and unsaturated fatty acids than the normal rice. Proteomic analysis using two-dimensional gel electrophoresis revealed differences in the protein profile of Seonong 17 and Keunnunjami. The results could serve as baseline information in evaluating the quality of these two giant embryo rice cultivars and provide a better understanding of their potential uses and food industry applications.     

不同培养基质对草菇营养成分及呈味物质的影响

在栽培条件一致的情况下,以5种不同培养基质栽培的草菇子实体为研究对象,测定粗蛋白、水解氨基酸、游离氨基酸、可溶性糖醇、有机酸及5′-核苷酸组成与含量,研究不同培养基质对草菇子实体营养成分及呈味物质的影响。结果表明以棉籽壳为基质栽培草菇,其粗蛋白及水解氨基酸含量及组成最优;以稻草为基质栽培草菇,其可溶性糖醇、有机酸含量最高。综合各种呈鲜成分,等鲜浓度值（equivalent umami concentration,EUC）范围为317.45-708.75g MSG/100g,其中以棉籽壳为基质栽培的草菇子实体EUC值最高,以刺芹侧耳菌渣为基质栽培的草菇EUC次之,以金针菇菌渣为基质栽培的草菇EUC [(317.45±13.67)g MSG/100g]最低,约为棉籽壳样品EUC值的44.79%。因此,培养基质对草菇呈味物质的影响显著,可根据需要的呈味物质选用不同的培养基质栽培草菇。     

Developmental Changes in the Free Amino Acid Pool and Total Protein Amino Acids of Pea Cotyledons (Pisum sativum L.)

Changes in the levels of twenty-two free amino acids and in the amino acid composition of the total protein were measured throughout the development of cotyledons of a dwarf garden pea, Pisum sativum cv Greenfeast, grown in a constant environment. A sensitive double-isotope dansylation technique was used. Fresh weight, dry weight, and protein content were also followed. Twenty of the amino acids showed synchronous changes in levels, giving a developmental pattern containing four peaks; major peaks occurred very early and very late in development. The amino acid composition of the total protein, which was always very different from that of the free amino acid pool, showed early changes to one consistent with the final storage protein composition of the seed. These changes included a 50% drop in methionine content and a 70% rise in cysteine. While the maximum free methionine level occurred early in development, that of cysteine was late.     

Molecular cloning and characterization of a cysteine-rich 16.6-kDa prolamin in rice seeds

An alcohol-soluble storage protein, a 16.6-kDa prolamin found in rice seeds, was purified from both the total protein body and purified type I protein body fractions. The partial amino acid sequences of three tryptic peptides generated from the purified polypeptide were analyzed. A part of the 16.6-kDa prolamin cDNA was amplified from developing seed mRNA by the reverse transcribed polymerase chain reaction using an oligo (dT) primer and a primer which was synthesized based on the partial amino acid sequence. The amplified product was used to isolate the full-length cDNA clone (lambda RP16) from a developing seed cDNA library. The cDNA has an open reading frame encoding a hydrophobic polypeptide of 149 amino acids. The polypeptide was rich in glutamine (20.0%), cysteine (10.0%), and methionine (6.9%). The cysteine content was higher than those of most other rice storage proteins. Messenger RNA of the 16.6-kDa prolamin was detected in seeds, but not in other aerial tissues.     

Rice seed globulin: a protein similar to wheat seed glutenin.

The globulin of the seed endosperms of rice has an isoelectric point of 6.4 and a M(r) of 26,000. There is one intra-disulphide bond, but no N-linked oligosaccharide chain. The amino acid sequence of the N-terminal and internal regions of the globulin was determined and found to be homologous with that of glutenin, the storage protein in the seed endosperms of wheat. Rice globulin and wheat glutenin were rich in glycine, and glutamic acid or glutamine, and in addition, wheat glutenin cross-reacted with antibody raised against rice globulin. These results suggest that rice seed globulin represents a protein similar to wheat seed glutenin.     

Enrichment of cereal protein lysine content by altered tRNA(lys) coding during protein synthesis

The world's major crops are deficient in lysine and several other amino acids essential for human and animal nutrition. Increasing the content of these amino acids in cereals, our major source of dietary energy, can help feed a global population whose reliance upon dietary protein is growing faster than crop yields. Here we document the heritable expression in rice, the world's major cereal crop, of tRNA(lys) species that introduce lysine at alternative codons during protein synthesis, resulting in a significant enrichment of the lysine content of proteins in rice seeds without changing the types or quantities of the seed storage proteins.     

栽培稻种子含氮量的基因型差异

采用田间试验研究了421个常规籼稻、63个常规粳稻和82个籼型杂交稻品种种子含氮量的基因型差异。结果表明,栽培稻种子含氮量变幅在0.85%~2.55%,平均为1.39%。种子平均含氮量最高的是籼型杂交稻,高达1.46%,显著高于常规粳稻(1.39%)和常规籼稻(1.37%)。不同类型的栽培稻种子含氮量呈正态分布,但频数分布最高的区间存在一定的差异。以50%品种的种子含氮量(累积百分数从25%~75%)为依据,常规籼稻、常规粳稻、籼型杂交稻分别集中在1.21%~1.52%、1.21%~1.51%、1.36%~1.53%。LSR测验表明,籼型杂交稻极差显著小于常规籼稻和常规粳稻,但常规粳稻与常规籼稻的差异未达显著水平,即籼型杂交稻种子含氮量比常规籼稻和常规粳稻的分布更加集中。不同类型栽培稻内的种子含氮量极差较大,可分为若干组,且各组间达极显著差异。     

Screening of Lysine-rich Plant Species and Identification of the Purified Proteins

The nutritional quality of seed proteins from cereals, such as wheat and rice, is comparatively low due to its deficency in lysine and some essential amino acids. In this research extensive varieties of plant seed samples were collected and screened by analysis of amino acid composition. Three lysing-rich species which contain more than 6.7% of lysine in total seed proteins were found. 31 kinds of proteins were purified from a species which contains 7.9% of lysine using the modified methods of IEF and SDS electrophoresis. One protein with PI 6.1 and 18 kD was identified which contains 11.4% of lysine and was rich in threonine, valine and isoleucine. This is the first example of the protein which could complement several limiting amino acids of wheat or rice. Further research on the structural gene encoding this protein would have great potential value for improvement of protein quality of these cereals.     

陕西三种特种稻米氨基酸及品质分析

以陕西洋县产茉莉香米、红香米和绿香粳米等 3种特种稻米为材料 ,分析了氨基酸及其它品质指标。结果表明 ,茉莉香米、红香米和绿香粳米均含有 1 7种氨基酸 ,氨基酸总含量 (mg/ 1 0 0 g)分别为 730 0、72 70、74 90 ;除Trp外 ,7种必需氨基酸占氨基酸总量分别为 34 .6 %、34 .5 %、34 .8% ;Lys含量 (mg/ 1 0 0g)分别为 5 5 0、5 2 0、5 30 ;粗蛋白质含量分别是 9.94 %、9.2 3%、8.5 2 % ;Cu含量 (mg/ 1 0 0g)分别是 0 .6 2、0 .94、0 .79;Zn含量 (mg/ 1 0 0 g)分别是 1 .99、1 .75、2 .0 2 ;Fe含量 (mg/ 1 0 0 g)分别是 1 .5 5、3.70、4 .5 0 ;直链淀粉含量分别是 1 5 .6 %、3.7%、1 5 .1 % ;胶稠度分别是 33mm、4 0 .6mm、78mm ;糊化温度分别是 6 .1级、6 .8级、7级 ;水分含量分别是 1 1 .2 7%、1 1 .5 5 %、1 2 .5 2 %。这 3种特种稻品质较优 ,具有推广价值