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1.
The study was conducted to demonstrate the effects of dietary protein and water temperature on growth and flesh quality of Songpu mirror carp (Cyprinus carpio) at an initial weight (165.24±5.08) g. Practical diets were formulated to contain five protein levels (29.12%, 31.46%, 34.49%, 38.17%, and 40.13%), and each diet was randomly assigned triplicate groups of 15 fishes at three temperatures (18℃, 22℃, and 26℃) in the recirculation system. Fishes were fed twice daily to apparent satiation for 56 days. Results indicated that fishes had higher weight gain rate at 22℃ and 26℃ than that at 18℃ (P〈0.05), but there were no significant differences between 22℃ and 26℃ (P〉0.05). Based on the weight gain rate, dietary protein level 29.12% could meet the requirement of the body at 18℃, 22℃, or 26℃. Crude protein, crude lipid, moisture and ash of muscle had no significant differences among those treatments (P〉0.05). pH (after 24 h) of muscle was the highest at 18℃ and the lowest at 22℃ (P〈0.05), but no differences were observed among different protein level groups at each temperature (P〉0.05). No significant differences on shear force, water holding capacity, collagen, glycogen and lactate among all the treatments were found (P〉0.05). It was concluded that when C. carpio fed to apparent satiation, the growth mainly depended upon temperature. Dietary protein could not significantly affect flesh quality, but temperature significantly affected pH of muscles. A dietary protein level 29.12% could meet the requirement of the body at 18℃, 22℃, or 26℃.  相似文献   

2.
The present study was to investigate the effect of monoclonal antibody against porcine 40-kDa adipocyte-specific membrane protein on endocrine secretion in pigs, in order to provide the evidence for application of this antibody to reduce excessive fat deposition in pig production. 40 Landrace×Saba pigs were randomly divided into 8 groups: 2 control groups were given saline with 10 mL, respectively, and the 6 treatment groups were given monoclonal antibody against porcine 40-kDa adipocyte-specific membrane protein with 0.1, 0.5, and 1.0 mg ·kg^-1 body weight at 15 or 60 kg body weight, respectively, all treatments were performed by intraperitoneal injection. The results showed that this monoclonal antibody could significantly reduce serum insulin level and increase levels of serum growth hormone (GH), insulin-like growth factor-1(IGF-1), triiodothyronine (T3), and tetraiodothyronine (T4) either at 15 or 60 kg body weight injection. However, more marked effect was observed at 15 kg body weight treatment. Moreover, the dose-dependent effect of this monoclonal antibody on endocrine secretion was also observed. This result revealed that this monoclonal antibody increased secretion of hormones regulating fat lysis and reduced secretion of hormones regulating fat synthesis, suggests the reduction of porcine excessive fat deposition by this monoclonal antibody was carried out through affecting hormones regulating fat metabolism.  相似文献   

3.
The development of the cotton fiber is very sensitive to temperature variation, and high temperature stress often causes reduced fiber yield and fiber quality. Short-term high temperature stress often occurs during cotton production, but little is known about the specific timing and duration of stress that affects fiber development. To make this clear, pot experiments were carried in 2014 and 2015 in a climate chamber using cotton cultivars HY370WR(less sensitive variety) and Sumian 15(heat sensitive variety), which present different temperature sensitivities. Changes of the most important fiber quality indices(i.e., fiber length, fiber strength and marcironaire) and three very important fiber development components(i.e., cellulose, sucrose and callose) were analyzed to define the time window and critical duration to the high temperature stress at 34°C(max38°C/min30°C). When developing bolls were subjected to 5 days of high temperature stress at different days post-anthesis(DPA), the changes(Δ%) of fiber length, strength and micronire, as a function of imposed time followed square polynomial eq. as y=a+bx+cx~2, and the time around 15 DPA was the most sensitive period for fiber quality development in response to heat stress. When 15 DPA bolls were heat-stressed for different durations(2, 3, 4, 5, 6, 7 days), the changes(Δ%) of fiber length, strength and micronire, as a function of stress duration followed logistic equations y=A_1-A_2/1+(x/x_0)~p+A_2. Referred to that 5, 10 and 15% are usually used as criteria to decide whether techniques are effective or changes are significant in crop culture practice and reguard to the fiber quality indices change range, we suggested that 5% changes of the major fiber quality indices(fiber length, fiber strength and micronaire) and 10% changes of fiber development components(cellulose, sucrose and callose) could be taken as criteria to judge whether fiber development and fiber quality have been significantly affected by high temperature stress. The key time window for cotton fiber development in response to the high temperature stress was 13–19 DPA, and the critical duration was about 5 days.  相似文献   

4.
The effects of acetylsalicylic acid (ASA), CaCl2, and ASA + CaCl2 on the photosynthetic apparatus and antioxidant enzyme activities were investigated in chrysanthemum Jinba (a cut flower cultivar) under low temperature stress with low light (TL stress) (16/12℃, day/night, PFD 100 μmol m^-2 s-1). The results showed that under TL stress, the net photosynthesis rate (Pn), carboxylation efficiency (CE), apparent quantum yield (AQY), maximal photochemical efficiency (Fv/Fm) of PSII, quantum yield of PSII electron transport (ФPSII), and photochemical quenching (qP) of the chrysanthemum leaves in all treatments were significantly decreased, but the decreases were alleviated by ASA, CaCl2, and ASA + CaCl2 treatments compared with the controls. The alleviating effect of ASA + CaCI2 was better than either ASA or CaCl2 single treatment. Moreover, the ASA + CaCl2 treatment highly improved the chlorophyll content, relatively improved the number and size of chloroplast and starch grain in the leaves of chrysanthemum plants compared with ASA and CaCl2 treatments. It was indicated that ASA and/or CaCI2 could regulate the photosynthetic functions in the leaves of chrysanthemum plants to enhance the resistance against TL stress. On the other hand, reduction in relative conductance rate implied that ASA and/ or CaCl2 could protect from membrane injury in leaves of chrysanthemum plants. The activities of SOD, POD, and CAT in the treated leaves of chrysanthemum were increased as compared with the controls. It was suggested that ASA and/or CaCl2 had positive regulation effects on the defence enzyme activities in chrysanthemum leaves which could protect the photosynthetic apparatus to a certain degree under the TL stress. In brief, the treatment of ASA together with CaCl2 was better for chrysanthemum plants to adapt TL stress than single ASA or CaCl2 treatments.  相似文献   

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F.  C.  L.  Zapico  C.  H.  M.  Aguilar  J.  M.  Aujero  B.  Y.  Disca 《农业科学与技术》2010,(5):101-105
Investigation into the paternity of four abaca (Musa textilis L, Nee) hybrids was done to ascertain the mode of transmission of selected morpho-agronomic traits and to detect possible heterosis. In situ morphological characterization was undertaken using twenty five qualitative and six quantitative characters. Results revealed that a great majority of the qualitative traits were shared by both parents and their hybrids. For the rest, the qualitative traits were inherited from one or the other parent though some variant phenotypes (i.e. chimerism) were also noted in the hybrids. Cases ofheterosis were also observed and this could be exploited to increase fiber yield in the hybrids. Though inconclusive due to factors such as the heterogenous nature of abaca plants in the field and the susceptibility of morphological traits to environmental fluctuations, this study has provided baseline information on abaca hybridity that can be verified using more robust technologies as molecular markers.  相似文献   

8.
Chilling is one of the major abiotic stresses limiting yield and quality of many important crops. For better understanding of chilling stress responses in tobacco (Nicotiana tabacum), growth rate and antioxidant enzymes of seedlings in 2 tobacco cultivars, viz., MSk326 (chilling sensitive variety) and Honghuadajinyuan (HHDJY, chilling tolerant variety) at chilling temperature (5℃) were studied. The results showed that the relative growth rate in chilling period to that in recovery period was significantly higher in roots than that in shoots for both cultivars, suggesting that shoots growth was more easily affected by chilling stress. Chilling stress increased peroxidase (POD) activity and reduced superoxide dismutase (SOD) activity in shoots of HHDJY, and catalase (CAT) activity was little affected. In the roots of HHDJY, chilling stress increased SOD and CAT activities, and had little effect on POD activity. For MSk326, chilling treatment increased SOD activity in shoots and declined CAT activity in roots. MDA concentration in both varieties was increased under the chilling stress, while it was decreased after seedlings were recovered growth for 4 d at normal temperature (25℃). It showed that tobacco seedlings might have the capacity of recovering from chilling injury for a short term, The relationship between the growth rate and antioxidant enzyme activity was analyzed by stepwise regression. It was found that there was a close relationship between relative growth rate of tobacco seedlings and CAT activity under chilling stress condition and regression equations containing CAT could be used in predicting seedling growth rate of tobacco under chilling stress condition.  相似文献   

9.
The changes in the concentrations of endogenous hormones and their influence on carbohydrate metabolism in leaves of micropropagated Fuji apple plants were studied under water deficiency stress. The results showed that water stress induced a rapid increase in the concentration of abscisic acid (ABA) and led to a decrease in concentrations of both zeatin and gibberellins (GAs). The concentration of indole-3-acetic acid (IAA) changed in an independent manner, which was not correlated with the different levels of water stress. With regard to the carbohydrates, the contents of sorbitol and sucrose increased, whereas the content of starch decreased. The increase in the concentration of ABA was significantly correlated with both the increase in the activity of aldose-6-phosphate reductase (A6PR) and the decrease in the activity of sorbitol dehydrogenase (SDH), indicating that ABA played a regulatory role in sorbitol metabolism. The concentration of ABA was positively correlated to the activity of sucrose-phosphate synthase (SPS) but negatively correlated to the activities of acid invertase (AI) and ADP-glucose-pyrophosphorylase (ADPGppase) in water-stressed plants, which indicated that ABA promoted sucrose synthesis and inhibited sucrose degradation and starch synthesis at the same time. Under conditions of water stress, the decrease in the level of zeatin was accompanied by a decrease in the activities of SDH and ADPGPPase. GAs concentration showed positive correlation with ADPGPPase activity. IAA showed no significant correlation with any of the enzymes tested in this study. The results of this study suggested that ABA might be one of the key factors regulating the distribution of carbohydrates under water stress. The metabolism of sorbitol and starch under conditions of water stress might be regulated by the combined action of many plant hormones.  相似文献   

10.
With the global warming and climate change in recent years, heat stress has become one of the major abiotic factors constraining production and productivity of crops in many regions around the world. Although the plants have developed some adaptive behaviors and avoidance mechanisms against heat stress, they wil be hurt under extreme high temperature. Exogenous compounds could enhance plant growth and development, antioxidant enzymes activities, chlorophyl and nutrient contents under stress conditions. Meanwhile, application of exogenous compounds sustains physiological and biochemical process and prevents plants from physiological changes under stress conditions. ln this review, effects of heat stress upon crops, and the functions of hormones in plant adaptation to heat stress are simply stated. Then, we intend to appraise how various phytohomrnones that are related to plant adaptation to heat stress. The role of abscisic acid (ABA), salicylic acid (SA) and polyamines (putrescine and spermine) under heat stress conditions are mainly discussed.  相似文献   

11.
以盐肤木(Rhus chinensis)、假连翘(Duranta repens)、老鸭嘴(Thunbergia erecta)和葛藤(Pueraria lobata)4种幼苗为试验材料,研究了人工模拟下的低温胁迫环境(6 ℃)对幼苗叶片生理生化及光合特性的影响。结果表明:(1) 随低温胁迫的延长,假连翘幼苗的叶绿素含量先升后降,其余3种幼苗持续下降,低温解除后均显著回升;4种幼苗的脯氨酸含量持续上升或波动;葛藤幼苗的可溶性蛋白质含量先升后降,其余幼苗显著上升, 且低温解除后有所增加;4种幼苗叶片可溶性糖含量以及丙二醛含量呈增加趋势,SOD活性持续上升或先升后降。低温解除后,盐肤木幼苗的SOD活性略有上升,其余幼苗显著下降。(2) 随低温胁迫的延长,4种幼苗的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)均持续下降,假连翘的胞间CO2浓度(Ci)持续上升,其余幼苗先降后升。低温解除后4种幼苗叶片PnGsTr均有不同程度的回升,Ci有不同程度的下降。低温胁迫和恢复48 h期间,4种幼苗的脯氨酸、可溶性糖、可溶性蛋白质含量的增加和SOD活性的稳定或增加,减轻了幼苗叶片细胞的膜脂过氧化程度, 维持了细胞膜的完整性,是幼苗对低温胁迫适应性反应的重要调节机制。恢复48 h时的PnGsTr均有不同程度的回升,Ci有不同程度的下降,说明4种幼苗有一定的抗寒能力。(3)用主成分分析法分别对生理生化指标和光合生理指标进行分析,均得出4种幼苗的抗寒性顺序为葛藤>盐肤木>老鸭嘴>假连翘,这一结果可为采矿石废弃地生态恢复的植物筛选提供科学依据。  相似文献   

12.
目的:观察不同麻醉方法对胸部手术患者应激激素的影响。方法:42例肺癌手术患者随机分为全麻复合硬膜外腔阻滞(GEA)组和全麻(GA)组,每组21例,分别测定麻醉诱导前、手术2h、术毕、术后1d的血浆去甲肾上腺素、肾上腺素、内皮素、C-反应蛋白、皮质醇的水平。结果:GEA组的血浆去甲肾上腺素、内皮素和血清皮质醇,术中、术后差异无显著性(P>0.05),与GA组比较差异有非常显著性(P<0.01)。两组血浆肾上腺素,术中、术后差异均无显著性(P>0.05)。两组血清C-反应蛋白,术中、术后均显著升高(P<0.01),组间比较差异无显著性。结论:硬膜外腔阻滞可以减轻胸部手术的应激反应。  相似文献   

13.
Rice (Oryza sativa L.) quality depends mainly on the characteristics of starch stored in kernels. Understanding the changes in starch characteristics in kernels during variety improvement would have great significance to improve rice quality. This study was designed to investigate the starch characteristics in the kernels and associated physiological traits of indica rice varieties in the lower reaches of the Yangtze River in China in last 80 years. Eight representative mid-season indica rice varieties were grown in the field. The results showed that the grain yield was significantly increased with the improvement of varieties and such an increase was mainly attributed to the increase in total number of spikelets. The tall varieties applied in the 1940s–1950s had higher protein content, relative crystallinity and infrared (IR) ratio of 1 045/1 022 cm−1. The semi-dwarf varieties applied in the 1980s–1990s had higher gel consistency, amylopectin content, IR ratio of 1 022/995 cm−1, and breakdown value. With the improvement of varieties, the amylose content, large-sized starch granule number and volume distribution, onset and peak of gelatinization temperature, gelatinization and retrogradation enthalpy, setback value, pasting temperature, viscosity of peak, hot and final, and 1-aminocycopropane-1-carboxylic acid (ACC) concentrations in panicles and root bleeding were gradually decreased, whereas the medium-sized starch granule number and volume distribution, activities of key enzymes in grains, and zeatin (Z)+zeatin riboside (ZR) contents in panicles and root bleeding at grain filling stage were gradually increased. Correlation analysis showed that starch thermodynamic characteristics were closely related to starch structure and components, key enzymes and hormones. The results suggest that starch quality was enhanced through the optimization of starch components, structure, thermodynamics, and the regulation of key enzymes in grains and hormones in panicles and root bleedings at grain filling stage during the improvement of mid-season indica rice.  相似文献   

14.
Heavy metals have been found to be endocrine disruptors in invertebrates.Lead is one of the most widespread elements of contamination,but there has been no research about the effects of lead stress on vitellogenin(Vg) gene expression in insects exposed to lead over multiple generations.In this paper,the effects of different concentrations of lead(0,0.3,4.8 and 76.8 mg kg~(–1)) on the expression of Vg in the beet armyworm over five successive generations were studied.The results showed that lead stress had significant effects on Vg expression in a dose-dependent manner.For females at the larval and adult stages,as lead concentration increased,Vg expression was significantly inhibited; for males at these two developmental stages,Vg expression was induced and increased as lead concentration increased.In addition,with the increase over stressed generations,inhibited effects for females and induced effects for males at the larval and adult stages became increasingly more obvious.However,at the pupal stage,Vg expression in the two genders was different from that at the larval and adult stages.The results indicate that lead stress can upregulate Vg expression in males which should be a useful indicator for environmental risk assessment.  相似文献   

15.
为探讨奶牛酮病与胰岛素抵抗的关系,选取产后14 d的酮病组(T)16头和健康对照组(C) 24头奶牛,比较酮病与对照组在能量平衡、肝功能状况、氧化应激、胰岛素敏感性以及耐糖量试验的差异.结果显示:酮病奶牛机体处于能量负平衡状态;肝功能指标中酮病组奶牛血浆天门冬氨酸转移酶、直接胆红素含量极显著高于健康对照组(P<0.01),总胆红素含量显著高于健康对照组(P<0.05),胆碱酯酶含量极显著低于健康对照组(P<0.01),总蛋白含量显著低于健康对照组(P<0.05),丙氨酸氨基转移酶、间接胆红素、白蛋白、球蛋白含量与健康对照组差异不显著,表明病牛肝脏受到一定程度的损害;酮病组奶牛血浆丙二醛、超氧化歧化酶含量显著高于健康对照组(P<0.05),表明病牛处于氧化应激状态;酮病奶牛血浆胰岛素敏感指数显著低于健康对照组(P<0.05),表明病牛的胰岛素敏感性下降.葡萄糖耐量试验显示部分酮病奶牛血糖含量显著高于健康对照组(P<0.05),在注射完葡萄糖120min后血糖浓度高达4.24 mmol/L,组间差异极显著(P=0.006),表明病牛存在胰岛素抵抗.奶牛酮病与胰岛素抵抗存在密切的关系,可能与肝功能与氧化应激有关.  相似文献   

16.
The present study reports the sublethal effects of the entomopathogenic fungus, Aschersonia aleyrodis(Webber) on Bemisia tabaci(Gennadius)(Homoptera: Aleyrodidae). A fungal suspension of A. aleyrodis isolate Aa005 containing 1×107 conidia mL~(–1) was sprayed against B. tabaci on eggplant leaves under greenhouse conditions. The effects of fungal application on survival as well as life table parameters of the whitefly were observed at different post inoculation periods. The results indicated that A. aleyrodis can significantly affect the survival of 1st, 2nd, and 3rd nymphal instars of B. tabaci. Developmental periods of different instar nymphs were not affected by fungal application. A. aleyrodis spores persisted well and significantly affected the survivorship of young instar nymphs of B. tabaci at different post incubation periods. Life table results suggested that A. aleyrodis has no impact on general fecundity and longevity of B. tabaci. When the pathogen was exposed to the open environment and maintained for a relatively longer period, a reduction in the reproductive rate and intrinsic rate of increase was caused by the fungal spores, though the sublethal effects were not as good as the control treatment. The results suggest that the ability of spores to suppress an increase in whitefly population persists well after incubation of spores to the external environment(up to 9 days).  相似文献   

17.
中草药饲料添加剂作为奶牛夏季抗热应激缓冲剂,在提高奶牛产奶量的同时,还能提高奶牛血液中的皮质醇指标.试验还采用高温法制作小白鼠热应激模型.结果表明,饲喂中草药的试验组能提高小白鼠的存活率,也能影响促肾上腺皮质激素的分泌,由此证明了中草药抗热应激缓冲剂对奶牛夏季热应激有可能是通过提高皮质醇等激素的分泌而显示出效用.  相似文献   

18.
徐满厚  薛娴 《勤云标准版测试》2013,33(10):3158-3168
以广布于青藏高原的高寒草甸为研究对象,进行模拟增温实验,探讨高寒草甸植被特征与温度、水分因子关系,并试图论证高寒草甸植被是否符合生物多样性代谢理论.结果表明:①高寒草甸植被物种多样性的对数与绝对温度的倒数呈显著线性递减关系,空气-地表-浅层土壤(0-20 cm)温度(R2 >0.6,P<0.01)较深层土壤(40-100 cm)温度(R2<0.5,P<0.05)对物种多样性影响大;其植被新陈代谢平均活化能为0.998-1.85 eV,高于生物多样性代谢理论预测值0.6-0.7 eV,这是高寒草甸植被对长期低温环境适应进化的结果.②除趋势对应分析和冗余分析显示,温度对植被地上部分影响较大,而土壤水分对全株影响均较大,适当的增温与降水均可极显著促进高寒草甸植被生长.③逐步回归和通径分析显示,40 cm、60 cm深度土壤水分对植被地上部分产生直接影响,20 cm高度空气相对湿度和40 cm深度土壤温度对其产生间接影响;40 cm深度土壤温度和60 cm深度土壤水分对植被地下部分产生直接影响,红外地表温度对其产生间接影响.深层土壤温度和水分对高寒草甸植被具有影响作用,这可能与增温后冻土的融化有关,但其机理尚待进一步研究.  相似文献   

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