高产水平下水肥耦合对小麦旗叶光合特性及产量的影响

为了探讨黄淮麦区冬小麦的高产机理,在大田条件下设置不同梯度的水肥耦合模式,分析了高产水平下旗叶光合特性与籽粒产量的效应.结果表明,不同模式的水肥耦合对旗叶光合特性和籽粒产量的影响不同,总体表现为土壤水分的处理效应大于施氮量的效应.旗叶光合速率(Pn)和气孔导度(G5)均随着土壤水分的增加而升高,表现为W3(充足水分)＞W2(适宜水分)＞W1(自然降水),差异达显著水平.胞间CO2浓度(Ci)随着土壤水分的增加而降低;不同的氮肥处理,旗叶Pn和Gs随着施氮量的增加而升高,表现为N3(270 kg·hm-2)＞N2(195 kg·hm-2)＞N1(CK),Ci在不同水分条件下与施氮量的关系不尽相同.不同水肥耦合模式对水分利用效率的影响表现为W2＞W3＞W1,并以W2N2为最高,不同处理组合的籽粒产量亦以W2N2为最高.表明高产条件下W2N2水肥组合应是高产高效的运筹模式.     

大叶类卷曲形绿茶加工工艺的优化研究

以福鼎大毫茶为原料,以摊放程度、杀青方式、二青方式为因素,进行3因素2水平L4(23)正交试验,从感官品质、生化成分含量、茶汤色度值和滋味化学鉴定得分等品质指标探讨微波杀青、微波二青工艺对大叶类卷曲形绿茶品质的影响。结果表明,微波工艺对提高绿茶"清汤绿叶"品质和滋味鲜爽度有益,能够显著提升卷曲形绿茶的色泽、明亮度、绿度、鲜度和总体品质。综合感官审评结果和品饮习惯,认为卷曲形绿茶的优选工艺流程为:"摊放减重率20%~25%→微波杀青→揉捻→炒二青→搓团提毫→烘干"(即Q4),制出的卷曲形绿茶外形色泽绿润、梗鲜绿,与传统工艺的品质风格迥然不同,香气清纯、滋味鲜爽、汤色绿艳、叶底绿亮均匀。     

不同锌水平对剑麻幼苗生长发育及生理代谢的影响

采用水培试验的方法,探讨了不同锌水平对剑麻幼苗生长发育及生理代谢的影响。研究结果表明,适量的锌可促进剑麻生长发育,高浓度的Zn2 则起抑制作用。同时发现,在一定Zn2 浓度范围内,适量的锌可不同程度地提高剑麻幼苗叶片POD、SOD、CAT及PPO等酶的活性,从而相应地降低剑麻幼苗叶片MDA、O2-的含量;适量的锌还可提高剑麻叶片叶绿素含量,增强光合作用,促进碳水化合物的合成和代谢。     

初烤烟叶专业化分级效率研究

设计4种工位的流程化分级方式,分别对第2、第4、第6炕次烟叶实施专业分级试验,研究不同的流程化分级方式对烟叶分级速度与质量的影响。结果表明:二工位和三工位流程化分级速度最快,分别为60.75、60.51kg/(人.工),较一工位分级分别多6.82、6.58 kg/(人.工),较四工位分级分别多9.38、9.14 kg/(人.工);四工位、三工位流程化分级时各炕次烟叶分级质量最好,烟叶等级合格率分别为91.78%、90.38%,比一工位分组分别高24.23及22.83百分点,比二工位分级分别高14.55及13.15百分点。对比4种不同方式的烟叶分级速度及分级质量,以三工位流程化分级效率最高。     

不同锌水平对剑麻幼苗生长发育及生理代谢的影响

采用水培试验的方法，探讨了不同锌水平对剑麻幼苗生长发育及生理代谢的影响。研究结果表明，适量的锌可促进剑麻生长发育，高浓度的Zn^2＋则起抑制作用。同时发现，在一定Zn^2＋浓度范围内，适量的锌可不同程度地提高剑麻幼苗叶片POD、SOD、CAT及PPO等酶的活性，从而相应地降低剑麻幼苗叶片MDA、O2^-的含量；适量的锌还可提高剑麻叶片叶绿素含量，增强光合作用．促进碳水化合物的合成和代谢。     

竹叶抗氧化物浸泡-乳清分离蛋白涂膜对冷藏富硒虹鳟蛋白质理化性质的影响

为从蛋白质水平解释竹叶抗氧化物浸泡-乳清分离蛋白涂膜对富硒虹鳟的保鲜机理,实验将鲜活富硒虹鳟去除头、内脏和表皮,切块后浸泡在1.0%的竹叶抗氧化物（AOB）溶液中（去离子水作为对照）,再进行乳清分离蛋白（WPI）溶液涂膜,25℃下鼓风吹干表面水分后置于4℃冰箱中贮藏1、4、7、10和13 d。测定鱼肉中肌原纤维蛋白和TCA-可溶性肽的含量、蛋白质的分子内价键,以及肌原纤维蛋白的总巯基含量、表面疏水性和二级结构,分析涂膜对冷藏富硒虹鳟蛋白质理化性质的影响。结果显示,冷藏期间,WPI组的肌原纤维蛋白含量和二级结构中β-折叠的含量显著高于对照组。冷藏1～7 d,WPI组的TCA-可溶性肽和二硫键含量以及表面疏水性指数（H₀）显著低于对照组,总巯基含量呈相反趋势,但随着冷藏时间的延长这些差异逐渐减弱。冷藏13 d时,WPI组与对照组无显著差异。3个实验组中,1.0%AOB+WPI组的肌原纤维蛋白、总巯基、氢键、二级结构中α-螺旋和β-折叠的含量在冷藏期间最高,H₀、TCA-可溶性肽、二硫键和二级结构中β-转角含量最低。WPI在鱼块表面形成一层薄膜,可...     

Investigations on the digestibility and metabolizability of the major nutrients and energy of maize leaves and barnyard grass in grass carp (Ctenopharyngodon idella)

In the uplands of northern Vietnam, culture of grass carp contributes significantly to income and household food security of Black Thai farmers. Maize is one of the most important upland crops and barnyard grass is the most important weed in the paddy rice fields. Thus, these are frequently used by small‐scale fish farmers as fish feed. An 8‐week feeding trial was conducted simultaneously in a recirculation and in a respirometric system to determine the digestibility and metabolizability of the nutrients of maize leaves and barnyard grass, to assess their crude protein, lipid and energy conversion and to estimate the energy allocation in grass carp. The following diets were used: diet ‘A’ (reference diet) containing 39% crude protein with 19.8 MJ kg^?1 gross energy; diets ‘B’, ‘C’ and ‘D’, which contained the same amount of the reference diet as the control diet, supplemented with a known amount of dried barnyard grass, dried maize leaves or fresh maize leaves, respectively. Five fish were assigned to each treatment in each experimental unit. Reference and test diets were fed to fish and faecal samples were collected and the oxygen consumption was measured in order to set up an energy budget of the fish over the whole experimental period. The weekly development of the body weight was recorded. The body weight gain of the fish fed diet D was significantly higher than that of the group fed diet A, which also in turn was significantly higher than that of fish fed diet B or C. The apparent digestibility coefficients (ADC) of nutrients and gross energy for the different experimental diets in fish kept in the aquaria were, for diets A, B, C and D respectively, 94.1%, 60.9%, 70.5% and 84.7% for protein, 91.3%, 60.7%, 76.8% and 71.8% for lipid; 95.9%, 44.5%, 60.6% and 69.1% for gross energy. The partial ADC of plant leaf ingredients were determined and barnyard grass and dried maize leaves were found to be not only poorly digestible but having negative impact on the digestibility of the reference diet, while fresh maize leaves were well digested. The results of the present study indicated that fresh maize leaves have a good potential to be used as supplement in diets for grass carp.     

玉米棒三叶光合性状对茎秆糖含量的影响

以YXD053和98A-04两个茎秆高糖自交系及Y6-1茎秆低糖自交系为材料,分析玉米棒三叶光合性状对玉米茎秆糖含量的影响。结果表明,3个自交系茎秆糖含量在雄穗始花期基本一致,雄穗始花后21 d茎秆糖含量差异最大。不同茎秆糖含量玉米自交系光合参数特征明显,与茎秆低糖自交系Y6-1相比,茎秆高糖自交系YXD053和98A-04光合速率有较长的高光合功能持续期,且在子粒发育后期有较高的光合速率。茎秆低糖自交系Y6-1胞间CO_2浓度及蒸腾速率高于茎秆高糖自交系YXD053和98A-04,气孔导度及叶面积对茎秆糖含量的影响在2个茎秆高糖自交系之间表现不一致。乳熟期棒三叶光合速率可作为茎秆糖含量的选择指标。     

银杏叶总黄酮提取方法的比较研究

采用正交试验法研究了溶剂乙醇的浓度、浸泡时间以及超声波提取时间3个因素对提取银杏叶中总黄酮含量的影响。结果表明:银杏叶总黄酮的最佳提取工艺是60%的乙醇浸泡10h后用超声波法提取25m in。用ZTC1+1天然澄清剂除杂,虽然回收率减低了25.81个百分点,但使银杏叶黄酮的纯度提高了7.13个百分点。微波水提取的效果优于超声乙醇提取和超声水提取。     

反相液相色谱法测定乌桕叶中氨基酸含量

以邻苯二甲醛(OPA)与9-芴基羰酰氯(FMOC-CI)作衍生剂,正缬氨酸为内标,利用二极管阵列(DAD)可变波长检测程序,采用柱前衍生RP-HPLC法测定了乌桕叶中氨基酸含量。结果表明:各种氨基酸的保留时间(Rt)、相对峰面积(Ax/AI)的RSD均较满意,回收率为93.21%~114.24%;乌桕叶中含有大量的氨基酸,总得含量在1.3000mg/mL左右,含量较高的是异亮氨酸(Ile)、谷氨酸(G lu)、天冬氨酸(Asp)、亮氨酸(Leu)和精氨酸(Arg),合计含量占总含量的60%以上。18种氨基酸中含有的人体必需氨基酸有7种,其总含量为0.5984mg/mL,占总氨基酸含量的46.03%。