黄花蒿提取物对菜蚜的杀虫活性研究

以丙酮、乙醇及水作溶剂，研究了黄花蒿全株干粉的3种溶剂提取物及其提取物不同浓度对菜蚜的触杀和胃毒活性。结果表明3种提取物对蚜虫都具有较强的毒杀活性，回归分析表明随着浓度升高杀虫时间缩短。LD50结果说明丙酮提取物的杀虫活性最强，乙醇提取物次之，最次是水提取物。独立样本t检验比较触杀效果和胃毒效果，表明黄花蒿各提取物均是触杀效果高于胃毒作用。     

夹竹桃叶提取液对红蜡蚧若虫防治效果的研究

为了解夹竹桃叶提取液对红蜡蚧若虫的防治效果,以无氯清水和95%乙醇为溶剂,提取得到夹竹桃叶水提液和夹竹桃叶醇提液,对红蜡蚧初孵若虫涌散期的防治效果进行初步研究。结果表明:夹竹桃叶提取液对红蜡蚧初孵若虫有较好的防治效果,随着提取液浓度的增加,防治效果增强;随着处理时间的延长,死亡率上升。夹竹桃叶水提液1∶10、夹竹桃叶醇提液1∶10浓度配比的防治效果最好。     

银杏叶提取物对发酵乳贮藏期理化和感官特性的影响

[目的] 考察不同添加量银杏叶提取物对发酵乳贮藏期品质的影响。[方法] 采用持水率、黏度、乳酸菌活菌数、抗氧化能力、感官评价方法测定不同添加量银杏叶提取物制备的发酵乳,并结合多元统计分析方法进行分析。[结果] 银杏叶提取物对乳酸杆菌和链球菌的活力没有显著影响,为保证活菌数在1.0×10⁷ CFU/g以上,建议该发酵乳最多冷藏9 天。在酸奶中添加银杏叶提取物可提高其抗氧化特性。添加银杏叶提取物的酸奶样品与对照组在风味和口感方面存在差异,且添加量越大差异越明显。[结论] 银杏叶提取物本身作为一种中成药,具有成为一种新的功能性酸奶成分的巨大潜力。     

Effect of yeast with bacteriocin from rumen bacteria on laying performance,blood biochemistry,faecal microbiota and egg quality of laying hens

The purpose of this study was to evaluate the effect of yeast with bacteriocin from Ruminococcus albus 7 (albusin B) on physiological state and production performance of laying hens. One hundred and twenty 26‐week‐old Single Comb White Leghorn (Hyline) laying hens were assigned into five groups including: (i) control group, (ii) yeast control (YC), (iii) 0.125% yeast with bacteriocin (0.125B), (iv) 0.25% yeast with bacteriocin (0.25B) and (v) 0.5% yeast with bacteriocin (0.5B). All supplements were added to the experimental diets of the hens from 26 to 46 weeks of age. Samples were collected every 4 weeks. Blood samples were collected from the wing vein for blood biochemical parameters assay, and faecal samples were collected by swab for the microbiota test. The egg production performance was recorded daily, and fresh eggs were collected for quality test. The blood biochemical assay results indicated that the addition of yeast with bacteriocin decreased the AST (aspartate aminotransferase) activity and it also affects the lactate concentration in laying hen blood. The result of egg quality indicated that yeast with bacteriocin supplementation had no effect on the mass of yolk and the strength of eggshell, but it had positive effect on the laying performance under hot environment. Low concentration bacteriocin (0.125B) supplementation could decrease total yolk cholesterol. The faecal microbiota result indicated that the supplementation of bacteriocin increased the lactobacilli counts. The yeast with bacteriocin supplementation significantly decreased the clostridia counts under hot environment condition, especially in hens receiving 0.25B. Combining the data from clinic chemistry, faecal microbiota, egg production and egg quality, the 0.25B supplementation may result in the best physiological parameter and egg production performance of laying hen.     

葡萄VvSUC12基因启动子的克隆及上游调控因子鉴定

枝干病害葡萄溃疡病近年来严重限制了葡萄产业发展。研究表明葡萄蔗糖转运蛋白参与寄主植物和病原菌的互作过程。为解析蔗糖转运蛋白VvSUC12在葡萄免疫反应过程中的功能,本研究克隆了VvSUC12基因翻译起始位点上游1 500 bp的启动子区,通过生物信息学分析发现该区域包含4个Dof转录因子结合序列(A/TAAAG)及多种激素调节与防御相关的顺式元件。实时荧光定量分析显示,接种可可毛色二孢菌显著诱导VvSUC12和VvDof19基因的表达。通过酵母单杂交实验筛选得到与VvSUC12启动子互作的转录因子VvDof19。酵母双杂交实验证实VvDof19具有自激活活性;进一步通过烟草瞬时表达发现Dof19-GFP的相对GUS活性约为对照GFP的9倍,表明转录因子VvDof19能够激活VvSUC12基因的表达。研究结果为深入研究蔗糖转运蛋白在葡萄免疫反应中的功能奠定基础。     

10种中草药提取物对棉铃虫、绿盲蝽触杀活性研究

棉铃虫Helicoverpa armigera和绿盲蝽Apolygus lucorum是两种重要的经济作物害虫。为寻找一种安全高效的防治新手段,本文对10种中草药提取物触杀活性开展了研究。结果表明,在10种中草药提取物中,苦杏仁杀虫活性最高,药后7 d棉铃虫、绿盲蝽校正死亡率分别为65.4%和100%。发现苦杏仁粗提物经不同溶剂萃取后发现,氯仿萃取时析出物对绿盲蝽触杀活性最高,药后7 d校正死亡率可达96.9%。硅胶柱分离结果表明,流分L36-48具有较高的触杀活性,药后7 d校正死亡率为84.7%。本研究评价了10种中草药提取物对棉铃虫和绿盲蝽的触杀活性,并对苦杏仁有效成分开展了初步的分离鉴定,以期为两种害虫高效安全的新型药剂开发提供理论基础。     

Yeast cell wall and live yeast products and their combination in broiler diets formulated with weekly ingredient variations

A 6‐week broiler study was conducted to evaluate whether subjecting the intestinal microflora of broilers to the effect of weekly variations in feed ingredients could be ameliorated by the inclusion of yeast‐derived feed additives: a yeast cell wall extract (YCW), live yeast culture (LY) or their combination (YCW + LY). Recent changes in ingredient prices have motivated producers to formulate diets not necessarily based primarily on corn and soya bean meal. Intestinal microflora in birds can vary significantly based on the ingredient composition of their diet, and the make‐up of the flora can influence overall bird performance. Within the three nutrient phases of this study, birds were fed either a traditional corn–soya ingredient profile or a variable‐ingredient regimen, which had weekly changes in the ingredient composition. There were consistent ameliorative effects of the yeast treatments in both the corn–soya and the variable‐ingredient groups throughout all 6 weeks, with the YCW + LY combination showing a reduced effect when compared to either product fed alone. The effectiveness of YCW and LY on ameliorating the effects of weekly ingredient variations appeared most effective during the starter and grower phases, but was less significant during the sixth week.     

Growth promoting effects of prebiotic yeast cell wall products in starter broilers under an immune stress and Clostridium perfringens challenge

This study was designed to investigate the growth promoting effects of supplementing different sources and concentrations of prebiotic yeast cell wall (YCW) products containing mannanoligosaccharides in starter broilers under an immune stress andClostridium perfringens challenge. Through a series of 6 individual studies either 240 or 288 newly hatched chicks were randomly distributed to specific dietary treatments. All birds received a commercial infectious bursa disease vaccine at 10 or 15 d age followed by an orally administeredClostridium perfringens challenge on d 15, 16, and 17; or 18, 19, and 20. Weekly BW, feed consumption, and daily mortality were recorded per pen. Each study was terminated after 21 d. Pooled data analysis of all studies revealed no effect between different product sources of YCW. Products from both sources produced a significant improvement in growth rate compared to control birds fed no YCW. However, a blend of two YCW products showed an approximate 15% improvement in growth rate and a 10% reduction in FCR. The optimum dose of any YCW product among those tested was determined to be approximately 250 ppm. Prebiotic YCW additives increased BW and improved feed conversion and may be considered as alternative growth promoters for starting broilers.     

Effect of different levels of dietary sweet orange (Citrus sinensis) peel extract on humoral immune system responses in broiler chickens

This experiment was conducted to evaluate the effects of different levels of sweet orange (Citrus sinensis) peel extract (SOPE) on humoral immune system responses in broiler chickens. Three hundred 1‐day broilers (Ross‐308) were randomly allocated to treatments varying in supplemental SOPE added in the drinking water. The experimental groups consisted of three treatments fed for 42 days as follows: a control treatment without feed extract, a treatment containing 1000 ppm of SOPE and a treatment containing 1250 ppm of SOPE. All treatments were isocaloric and isonitrogenous. Broilers were vaccinated with Newcastle disease virus (NDV), avian influenza (AI), infectious bursal disease (IBD) and infectious bronchitis virus (IBV) vaccines. Antibody titer response to sheep red blood cells (SRBC) was higher in the group fed 1250 ppm of SOPE (P < 0.05) as well as for immunoglobulin G (IgG) and IgM. Similarly, antibody titer responses to all vaccines were constantly elevated (P < 0.05) by SOPE enrichment in a dose‐dependent manner. Relative weights of spleen and bursa of Fabricius were unaffected by treatments. Dietary SOPE supplementation may improve the immune response and diseases resistance, indicating that it can constitute a useful additive in broiler feeding. Thus, supplying SOPE in rations may help to improve relative immune response in broiler chickens.     

四种植物提取物对斜纹夜蛾卵的毒杀效果

以斜纹夜蛾卵为研究对象．对雷公藤Tripter gium wilfordii茎、皂荚Gleditsia sinensis Lam．刺、苦参Sophora flavescens和博落茴Macleya cordata等4种植物材料的正已烷及乙酸乙酯提取物的杀卵活性进行了测定。结果表明：博落茴的乙酸乙酯提取物对斜纹夜蛾卵有较好的杀伤力,校正未孵化率高达95．63%;雷公藤的乙酸乙酯提取物和苦参的正已烷提取物对斜纹夜蛾卵的孵化也有明显的抑制作用。