~(15)N-甘氨酸单剂量终产物法研究妊娠和非妊娠母猪整体蛋白质周转代谢

采用15N-甘氨酸单剂量终产物法研究了妊娠和非妊娠母猪在不同阶段整体蛋白质代谢的周转速率以及氨基酸利用效率的差异。结果表明:刚配种时,妊娠母猪与非妊娠母猪蛋白质代谢参数差异不显著(P>0.05);妊娠30d时,妊娠母猪蛋白质合成速率,降解速率、周转速率显著低于非妊娠母猪(P<0.05),但沉积速率提高了25%(P<0.05);妊娠后期,妊娠母猪氨基酸代谢库氮流量、周转速率以及蛋白质合成速率和降解速率显著(P<0.01)提高,蛋白质的沉积速率增加了71.1%(P<0.01)。     

早籼突变体稻米品质变化的研究

本试验分析测定了 1 1个优质早籼品种 (系 )及从其中诱变获得的 1 9个突变体的稻米品质。结果表明 ,与原亲本相比 ,辐射诱发突变体的精米率、整精米率、垩白米率、垩白度、直链淀粉含量、碱消值、胶稠度和蛋白质含量等品质指标以及淀粉粘滞性谱 (RVA谱 )发生了明显或比较明显的变化 ;大多数突变体同时在一个或多个主要品质性质上产生了正向和负向变异 ,少数突变体基本保持了原亲本的稻米品质 ,个别的甚至在此基础上还有若干品质性状得到显著改进。     

黄芪组方浓缩物和半胱胺对肥育猪生长性能和体蛋白动态代谢的影响

采用稳定同位素(15N-Gly)示踪技术和氮平衡试验,比较研究了外源代谢调节物(黄芪组方浓缩物、半胱胺)对PIC肥育猪生长性能、体蛋白动态代谢和氮沉积的影响。选用32头体重59.82±1.32kg的PIC商品猪,随机分成4个处理组,CON组、NCAE组、CAE组和CS组。每处理设4个重复,每重复2头猪。试验结果表明:(1)黄芪组方浓缩物和半胱胺均明显提高肥育猪的生长性能,其中基础日粮+半胱胺70mg/kg组(CS组)显著提高肥育猪日采食量(P<0.05),基础日粮+黄芪组方浓缩物250mg/kg组(CAE组)和基础日粮+非稳定化处理黄芪组方浓缩物250mg/kg组(NCAE组)显著提高饲料利用率(P<0.05),从而使肥育猪日增重均显著提高(P<0.05)。(2)黄芪组方浓缩物和半胱胺均显著增加肥育猪体蛋白沉积速率、显著提高氨基酸利用效率和生物学效价(P<0.05);黄芪组方浓缩物显著提高可消化氨基酸用于合成体蛋白质的速率(P<0.05),降低内源尿氮排泄速率。(3)黄芪组方浓缩物和半胱胺调控体蛋白沉积的强度和途径不同:半胱胺主要通过降低体蛋白降解速率26.71%,增加体蛋白沉积速率63.53%(P<0.05);黄芪组方浓缩物通过降低体蛋白降解速率和提高体蛋白合成速率,共同增加体蛋白沉积,与对照组相比,NCAE和CAE组体蛋白质降解速率分别降低了24.84%和13.66%,体蛋白合成速率分别提高了22.86%和19.18%。(4)黄芪组方浓缩物和半胱胺均可改善氮代谢,体现在CS组显著提高氮的净利用率和生物学效价(P<0.05),CAE组极显著改善沉积氮、氮的净利用率和生物学效价(P<0.01),NCAE组显著提高氮的净利用率和生物学效价(P<0.05)。     

植物种子重要成分的代谢工程

本文综述了植物种子重要成分(淀粉、糖类、蛋白质和油脂等)以及块茎、果实的代谢工程研究进展。     

皖南单季稻区种植利用紫云英对水稻产量、氮肥利用率及稻米品质的影响

为了探明种植利用紫云英在稻田系统的化学氮肥替代潜力,通过4年田间定位试验,设置冬闲+不施氮(-N)、冬闲+100% N(100% N)、紫云英+不施氮(GM)、紫云英+40%氮肥(GM+40% N)、紫云英+60%氮肥(GM+60% N)和紫云英+80%氮肥(GM+80% N)共6个处理,研究不同处理对水稻产量、氮素吸收、氮肥利用率和品质的影响。结果表明,GM+80% N处理水稻产量、氮素积累量、糙米率、整精米率、垩白粒率、蛋白质和锌含量与100% N处理差异不显著,氮肥利用率、精米率、钙、镁和铁含量显著高于100% N处理(P<0.05),垩白度和直链淀粉含量显著低于100% N处理(P<0.05);GM+60% N处理水稻产量、糙米率、整精米率、垩白粒率、垩白度和锌含量与100% N处理差异不显著,氮肥利用率、精米率、钙、镁和铁含量显著高于100% N处理(P<0.05),氮素积累量、直链淀粉和蛋白质含量显著低于100% N处理(P<0.05)。GM+60% N处理水稻产量、氮素积累量、糙米率、精米率、整精米率、垩白粒率、直链淀粉、蛋白质、钙、镁、铁和锌含量与GM+80% N处理差异不显著,但氮肥利用率低于GM+80% N处理。综上所述,在紫云英翻压还田的基础上,水稻季氮肥减施40%比较适宜,且有利于水稻节肥增效并获得优质稻米。     

不同基因型玉米氮素利用的机理研究

利用15N标记研究了不同基因型玉米氮素利用效率的差别;分析了不同基因型玉米豫单2002(高蛋白)和豫单136(低蛋白)籽粒中蛋白质含量及单粒蛋白质含量在灌浆期的动态变化;测定了籽粒中硝酸还原酶和谷氨酰胺合成酶活性的变化动态,结果表明蛋白质含量高的玉米品种氮素利用率较高,豫单2002比豫单136高7.79%;二者的硝酸还原酶活性在灌浆期内变化趋势相近,授粉0~30d,也相差不大,授粉后30d至收获,豫单2002的硝酸还原酶活性始终高于豫单136,授粉后第45天时,豫单2002比豫单136高出32.77μg NO2-/(g FW.h);豫单2002与豫单136籽粒的谷氨酰胺合成酶活性在籽粒灌浆期的变化动态均呈“∽”型,且豫单2002一直高于豫单136;高的酶活性促进了蛋白质的形成。本研究为高蛋白玉米的蛋白质形成基础提供了理论依据。     

抗恩诺沙星单克隆抗体杂交瘤细胞株的筛选及竞争ELISA试剂盒的研制

利用合成的完全抗原(BSA-ENR)免疫小鼠,通过细胞融合技术和间接竞争ELISA筛选出了能分泌恩诺沙星单克隆抗体的杂交瘤细胞株,以此为基础研制恩诺沙星残留检测的竞争ELISA试剂盒(competitive ELISA ENR-Kit),并测定其性能。结果表明:筛选出的2株杂交瘤细胞,单抗亚类均为IgG1型,其中4G1-B3株的ENR mAb间接ELISA效价为1:1.024×106,亲和常数(Ka)为9×1010L/mol;竞争ELISA试剂盒的线性检测范围为0.05~101.6μg/L、灵敏度0.05μg/L、半数抑制浓度(IC50)1.1μg/L,与其他化合物的交叉反应率(CR%)均小于0.01%,鸡肉样、鸡肝样、鱼肉样和牛奶样的平均添加回收率分别为81.5%8、7.6%、84.3%和95%,不同基质添加恩诺沙星标准品做竞争ELISA对ENR-Kit检测结果影响小,试剂盒保存期6个月以上。结果说明该竞争ELISA试剂盒具有快速、敏感、特异、简便等特点,适用于ENR残留的快速检测。     

自由式分娩猪栏设计及应用效果

为克服分娩限位栏和传统分娩猪栏固有缺点,增加母猪运动量,降低仔猪死胎率和压死率,该研究设计了一种自由式分娩猪栏,并对其生产使用效果进行了评价。结果表明：分娩限位栏、传统分娩猪栏和自由式分娩猪栏的死胎率分别为(10.5±3.2)%,(4.1±2.5)%和(4.2±2.6)%（P＜0.001）。无仔猪防压构件的传统分娩猪栏母猪从站立到躺卧时的后驱下落时间为3.9 s,产后24 h的翻滚频次高,仔猪被压死的风险较高,其仔猪压死率达(25.5±9.8)%,而分娩限位栏与自由式分娩猪栏的仔猪压死率相对较低,分别为(10.8±3.6)%和(9.24±5.5)%。与分娩限位栏相比,自由式分娩猪栏及传统分娩猪栏的仔猪断奶质量和日增质量都较好（P＜0.05）。该研究认为自由式分娩猪栏有利于改善母猪及仔猪的健康与福利。     

太空诱变玉米核不育材料可育花药与不育花药的生化特性分析

为探讨太空诱变处理玉米核不育材料的可育株、不育株花药的生理生化特性差异,对可育、不育材料不同发育时期花药的可溶性糖、可溶性淀粉、蛋白质含量以及游离脯氨酸含量进行了测定。结果表明:太空诱变处理玉米核不育材料的可育株花药中的可溶性糖、淀粉、蛋白质以及游离脯氨酸含量均高于不育株花药的,且可育株花药中的可溶性淀粉、蛋白质和脯氨酸含量都随着花药的发育逐渐累积,在不育株花药中这些指标的变化不明显。     

秋水仙素和二甲基亚砜诱变选育短蔓型甘薯新品种短蔓3号

为诱变甘薯非倍性有益突变体,用0.05%秋水仙素(C22H25O6)和2%二甲基亚砜(DMSO)混合水溶液处理秦薯1号甘薯种子,时间分别为12、24、48和72h,培养温度分别为5℃~6℃、10℃~12℃、15℃~16℃、18℃~20℃和30℃。结果表明,用0.05%秋水仙素和2%DMSO混合水溶液间歇处理甘薯种子24h,培养温度为15~16℃时,可获得良好的诱变效果。对处理后代进行了细胞学观察比较,未发现染色体数目变异,但出现可遗传的短蔓变异,进而选育出高产、高淀粉、高蛋白、高铁、高锌短蔓甘薯新品种短蔓3号。     

Molecular degradation rate of rice and corn starches during acid-methanol treatment and its relation to the molecular structure of starch

The degradation rates of rice and corn starches with different contents of amylose treated in methanol containing 0.36% HCl at 25 degrees C for 1-15 days were evaluated by monitoring the weight average degree of polymerization of starch. A two-stage degradation pattern during acid-methanol treatment was found for the starches studied, which were the slow (first) and the rapid (second) degradation stages. Waxy starches showed a shorter time period of the first stage than that of nonwaxy starch. Rice starch showed a shorter time period of the first stage and a higher degradation rate of the second stage than the counterpart corn starch with similar amylose content. Despite the botanic source and amylose content of starch, the degradation rate of starch in the second stage significantly (p < 0.05) correlated to the S/L ratio (r = -0.886) and polydispersity (r = 0.859) of amylopectin branch chains of native starch.     

Effects of Granular Structures on the Pasting Behaviors of Starches

Japonica (Tainung 67 [TNu67]) and waxy (Taichung 70 [TCW70]) rice, normal and waxy corn, and cross-linked waxy rice and corn starches were used in an investigation of the influence of the granular structure on the pasting behavior of starch, using small amplitude oscillatory rheometry. Both normal corn and normal rice (TNu67) starches had the highest storage moduli (G′), followed by their cross-linked versions; native waxy corn and rice starches had the lowest. Native waxy starches showed paste characteristics (G′ < 500 Pa; tan δ > 0.2) at concentrations of up to 35%. However, cross-linked waxy starches exhibited gel behavior at 10% concentration (cross-linked TCW70) or higher (cross-linked waxy corn starch). The degrees of swelling power were in the order: TCW70 > native waxy corn > TNu67 ≅ cross-linked TCW70 ≅ normal corn ≅ cross-linked waxy corn starches. Solubilities were in the order: normal corn > TNu67 > native waxy > cross-linked waxy starches. The addition of 2% purified amylose from indica rice (Kaohsiung Sen 7) did not induce gelation of waxy corn starch. Swelling powers of normal corn, TNu67, and crosslinked waxy starches were similar, but normal corn and TNu67 had much higher G′ value. Such results implied that the formation of gel structure was governed by the rigidity of swollen granules and that the hot-water soluble component could strengthen the elasticity of the starch gel or paste.     

不同类型玉米籽粒淀粉积累、相关酶活及基因表达差异分析

为探究不同类型玉米淀粉形成机理,对普通玉米、甜玉米、糯玉米淀粉积累、相关酶活及基因表达进行测定,分析不同类型玉米淀粉积累、相关酶活及基因表达之间的差异及相互关系。结果表明,不同类型玉米总淀粉和直链淀粉百分含量为:普通玉米>糯玉米>甜玉米,支链淀粉百分含量为:糯玉米>普通玉米>甜玉米,灌浆期间总淀粉和直链淀粉含量3个玉米类型间差异显著;灌浆期间,普通玉米各淀粉合成相关酶活性最高,甜玉米淀粉合成相关酶活性最低,糯玉米则介于普通玉米和甜玉米之间,但其GBSS酶活性很小。灌浆期间3个类型玉米除GBSS酶活性差异不显著外,其他淀粉合成相关酶活性差异显著;普通玉米淀粉合成相关基因表达量总体均高于甜玉米和糯玉米,甜玉米和糯玉米相关突变基因仍存在表达。表明不同类型玉米淀粉含量和组成上差异明显;普通玉米淀粉的形成需要淀粉合成相关酶相互作用,淀粉合成相关酶活性的缺失会改变淀粉组成;不同类型玉米淀粉合成相关基因表达差异显著,但都存在转录活性。对普通玉米进行相关性分析同时发现,淀粉的合成不仅受到转录调控,还受到转录后调控,淀粉的合成是淀粉合成各酶之间相互协调的结果。     

Metabolic Responses to Venezuelan Corn Meal and Rice Bran Supplemented Arepas (Breads)

The metabolic responses to South American foods remain to be determined. Using glycemic index (GI) and insulinemic index (II) values as references for therapeutic potential of foods, this study investigated the glucose responses to a typical Venezuelan corn bread (arepa) and to an arepa supplemented with rice bran. Adding rice bran to the bread increased the content of resistant starch and dietary fiber measured as total, soluble, and insoluble dietary fiber. It also increased the protein content of the arepa. Three meals, white wheat bread, 100% corn meal arepa, and an arepa supplemented with 20% rice bran, were administered within a one‐week period. Available starch in the foods was determined to provide 50 g of available carbohydrate per meal. To calculate the indices, bread was used as the reference. The GI and II of the two arepa meals were significantly smaller than the GI and II of white wheat bread, although the differences between the two types of arepas were not significant. It is concluded that Venezuelan arepas (corn meal bread) may have potential health benefits and that the presence of 20% rice bran in the arepa meal did not produce a significant improvement in the glucose response. Due to the presence of antioxidant elements in the supplemented arepa and its higher protein, dietary fiber, and resistant starch content, it may have a potential preventive effect against the development of other pathologies.     

蚯蚓活动对稻麦轮作系统中土壤微生物量碳的影响

在建立6 a的稻麦轮作田间小区试验中,研究了2001年稻季至2004年麦季(共6季)蚯蚓活动对土壤微生物量碳(MBC)的影响。本研究设计了秸秆施用方式(混施或表施)×蚯蚓(接种或剔除)以及对照共5个处理,各3个重复。实验结果表明:在该生态系统中,无论采用何种秸秆施用方式,蚯蚓活动均能显著提高土壤MBC(p<0.05)。秸秆的施用会减弱同年内土壤MBC在麦季成熟期高于稻季的趋势,而蚯蚓的作用使该差异变得更显著(p<0.05)。在0~5 cm土层中,蚯蚓对MBC的积极作用在秸秆混施时比表施更明显,在5~10 cm土层中则相反,而在10~20 cm土层中的作用效果基本一致。     

Flavor Retention and Physical Properties of Rice Cakes Prepared from Coated Rice Grain

Flavored rice cakes are produced commercially by spraying a flavor coating on the cake surface. This study describes a method of making a flavored coating that is applied to individual rice grains before puffing and results in a more uniform flavor distribution. Rice was coated at 5% or 10% levels with coating materials made of jet‐cooked (JC) starch or starch cooked in a water bath (WB), corn starch powder, salt, and a flavor compound. The viscosity of coating materials made with WB starch was twice that of coatings made of JC starch. Rice coated at 10% level had decreased specific density of rice cakes. Rice cakes made from coated grain were similar in appearance to cakes made from uncoated rice but had higher flexural strength. Retention of flavor volatiles after puffing the coated grain was 82.8–56.8% for apple, 72.5–40.3% for anise, and 52.5–24.8% for onion flavor. The flavor volatiles measured in the rice cakes decreased during a three‐month storage period to 49.3% for apple, 25.8% for anise, and 10.1% for onion flavor. Slightly higher retention of flavor volatiles was observed in cakes made with WB starch than in cakes made with JC starch. The difference in retention of flavor volatiles between starch slurry or starch‐oil emulsion treatments was small.     

Utilization of Hydroxypropylated Waxy Rice and Corn Starches in Korean Waxy Rice Cake to Retard Retrogradation

A traditional waxy rice gel cake in Korea, Injulmi, was prepared with hydroxypropylated waxy rice and corn starches (molar substitutions 0.13 and 0.11, respectively), and the textural and retrogradation characteristics of the cake were compared with a conventional cake made of waxy rice flour. In the pasting viscogram, hydroxypropylated starches exhibited reduced pasting temperatures, but increased peak viscosities compared with the unmodified starches. Under differential scanning calorimetry, the T_g′ and ice melting enthalpy of the starch gel cakes were reduced by hydroxypropylation, which indicated that the modified starches had higher water‐holding capacity than the unmodified starches. The degree of retrogradation, as measured by the hardness of the gel cake and the melting enthalpy, was significantly reduced by hydroxypropylation and hydroxypropylated waxy rice starch was more effective in retarding the retrogradation than hydroxypropylated waxy corn starch     

密闭式立体育秧系统水稻育苗基质配方研究

针对水稻育苗用土资源日益减少、适用于密闭式水稻立体育秧基质缺乏等制约水稻工厂化育苗技术发展的问题,该文以粉碎稻壳、粉碎玉米秸秆、珍珠岩、大田土为基质材料,设计3种单一基质CK1(100%大田土)、CK2(100%盼碎玉米秸秆)、CK3(100%粉碎稻壳)和按体积比配制的6种复合基质S1(80%粉碎稻壳+10%大田土+10%珍珠岩)、S2(60%粉碎稻壳+20%大田土+20%珍珠岩)、S3(40%粉碎稻壳+40%大田土+20%珍珠岩)、T1(80%粉碎玉米秸秆+10%大田土+10%珍珠岩)、T2(60%粉碎玉米秸秆+20%大田土+20%珍珠岩)、T3(40%粉碎玉米秸秆+40%大田土+20%珍珠岩)进行育苗试验,并分析9种基质的理化指标,结果表明,各处理的理化指标含量差异显著;添加粉碎稻壳、粉碎玉米秸秆复合基质的秧苗品质要优于单一基质;添加玉米秸秆的复合基质(T1、T2、T3)秧苗品质要优于添加稻壳的复合基质(S1、S2、S3);粉碎稻壳、粉碎玉米秸秆的添加量对秧苗生长影响较大,其添加量在60%(S2和T2)时,秧苗的各性状表现最优,其他2个处理差异不显著。以秧苗的农艺、生物量、力学性能作为评价指标,最佳的复合基质配方为处理T2。田间栽培结果表明,与常规育苗模式(普通平面大棚+自然光+大田土)对比,经T处理(密闭式立体+LED日光灯+T2基质)的秧苗在穴数上没有差异,株高平均值117.9 cm,低于对照的常规育苗平均值121.8 cm;千粒质量平均值25.35 g;其他各项指标平均值均高于常规育苗,实测增产5.9%。该研究结果可为密闭式水稻立体育秧系统高效稳定生产提供参考。     

In Vitro Starch Digestibility and Expected Glycemic Index of Kodo Millet (Paspalum scrobiculatum) as Affected by Starch–Protein–Lipid Interactions

The effect of starch–protein–lipid interaction on the in vitro starch digestibility and expected glycemic index (eGI) of kodo millet flour (MF) was investigated. Debranned MF and the flour with lipid removed, protein removed, or both lipid and protein removed (MF‐L‐P) were subjected to digestion assays. The in vitro starch digestibility and eGI of the millet samples and millet starch were compared with rice or wheat flour. Rapidly digestible starch, slowly digestible starch, and resistant starch (RS) of the samples were also calculated. Protease treatment and defatting resulted in significant reduction (P < 0.05) in protein and lipid contents of samples. Significant increases in the in vitro starch digestibility and eGI of samples were observed after removal of protein, lipid, or both. The effect of lipid removal on in vitro starch digestibility of kodo millet was found to be more significant, compared with when proteins were removed. The eGI increased from 49.4 for cooked MF to 62.5 for MF‐L‐P. The eGI of cooked kodo millet starch was significantly lower than that of cooked rice flour. The RS (1.61%) of cooked rice was the least among the samples. The in vitro starch digestibility and eGI of rice were significantly higher than those of MF. Processes applied to kodo millet, such as decortication, that result in the removal of proteins, lipids, or both (especially lipids) would result in an increase in its in vitro starch digestibility and eGI. We therefore advocate for the development of acceptable products from whole millets to maintain its hypoglycemic property.     

Comparison of Physicochemical Properties and Structures of Sugary‐2 Cornstarch with Normal and Waxy Cultivars

Starches from normal, waxy, and sugary‐2 (su2) corn kernels were isolated, and their structures and properties determined. The total lipid contents of normal, waxy, and su2 corn starches were 0.84, 0.00, and 1.61%, respectively. Scanning electron micrographs showed that normal and waxy corn starch granules were spherical or angular in shape with smooth surfaces. The su2 starch granules consisted of lobes that resembled starch mutants deficient in soluble starch synthases. Normal and waxy corn starches displayed A‐type X‐ray patterns. The su2 starch showed a weak A‐type pattern. The chain‐length distributions of normal, waxy, and su2 debranched amylopectins showed the first peak chain length at DP (degree of polymerization) 13, 14, and 13, respectively; second peak chain length at DP 45, 49, and 49, respectively; and highest detectable DP of 80, 72, and 76, respectively. The su2 amylopectin showed a higher percentage of chains with DP 6–12 (22.2%) than normal (15.0%) and waxy (14.6%) amylopectins. The absolute amylose content of normal, waxy, and su2 starches was 18.8, 0.0, and 27.3%, respectively. Gel‐permeation profiles of su2 corn starch displayed a considerable amount of intermediate components. The su2 corn starch displayed lower gelatinization temperature, enthalpy change, and viscosity; a significantly higher enthalpy change for melting of amylose‐lipid complex; and lower melting temperature and enthalpy change for retrograded starch than did normal and waxy corn starches. The initial rate of hydrolysis (3 hr) of the corn starches followed the order su2 > waxy > normal corn. Waxy and su2 starches were hydrolyzed to the same extent, which was higher than normal starch after a 72‐hr hydrolysis period.