Effect of Human Menopausal Gonadotropin,17β-estradiol and Epidermal Growth Factor on the Quality of in vitro Maturation Bovine Oocytes

For optimizing in vitro maturation system of bovine oocytes,we firstly examined the influence of four different hormonal regimes(FSH+LH,HMG,FSH+LH+E₂ and HMG+E₂) on oocyte maturation rates.Then we studied the effects of epidermal growth factor (EGF) in the above defined medium on bovine oocyte maturation,in vitro development and quality of parthenogenetic embryos.The cell apoptotic index of parthenogenetic blastocysts was detected by TUNEL.No significant difference was observed in maturation rates in four groups supplemented with different hormones.However,human menopausal gonadotropin (HMG) provided steady maturation results in replicates.Maturation of oocytes was promoted by supplementation with 17β-estradiol (E₂).Combination of HMG and E₂ gave rise to steady and efficient mature results.The presence of EGF at 30 ng/mL concentration significantly increased maturation rate and blastocyst rate and reduced apoptotic cells in parthenogenetic blastocysts.Therefore,the optimal oocyte maturation solution could be supplemented with 0.075 IU/mL HMG,1 μg/mL E₂ and 30 ng/mL EGF.     

Effect of Different Concentrate-roughage Ratios on Rumen Degradability of Cassava Stems and Leaves Total Mixed Ration in Goat

The rumen degradations of TMR were studied in this experiment,in which cassava stems and leaves were used as roughage and formulated with concentrate in different proportions.The purpose of this study was to formulate the available TMR for finishing goat,and provide a theoretical basis for the applications of cassava stems and leaves in goat production.Six Hainan Black goats with permanent rumen fistulas were selected,the rumen degradabilities of DM,CP,NDF and ADF of TMR with 6 different concentrate to forage ratio（2:8,3:7,4:6,5:5,6:4 and 7:3）were tested using nylon bag method.The results showed that,the DM effective degradabilities at the ratio of 4:6,5:5,6:4,7:3 were significantly higher than that of 2:8 and 3:7（P<0.05).CP effective degradabilities at the ratio of 2:8,3:7,4:6 were significantly higher than that of 5:5,6:4 and 7:3（P<0.05).The NDF effective degradation at the ratio of 5:5 was significantly higher than that in the other groups（P<0.05).The ADF degradation at the ratio of 3:7 was significantly higher than that of 4:6,5:5, 6:4 and 7:3（P<0.05).The results indicated that,the nutrient degradation in rumen were higher when the concentrate to forage（cassava stems and leaves）ratio in TMR were 3:7,4:6 and 5:5,and the recommended ratio range were 4:6 to 5:5 in production practice.     

基于纵向传导的蔬菜批零价格关系研究——以北京市果类蔬菜为例

从蔬菜产业的纵向看,批发和零售是两个重要环节,蔬菜批发价格和零售价格的走势以及它们之间的关系是各界关注的焦点。本文以北京市场为例,以番茄和黄瓜两种果类蔬菜的按日批零价格为对象,运用有限分布滞后模型和误差修正模型进行实证分析,研究蔬菜批零价格间的传导关系,并在此基础上揭示蔬菜批发价格在蔬菜价格形成中的作用。研究发现:蔬菜批零价格走势基本一致,相关系数很高;批零价格间存在批发价格向零售价格单向传导的因果关系;批零价格的传导是顺畅的,但不同种蔬菜传导的时间效应有所不同;批发价格在蔬菜价格形成中占据主导作用,当蔬菜价格受到冲击时,若零售价格过高则其会向着批发价格下调,若批发价格过高则零售价格会随之走高。     

叶面喷施吲哚乙酸对油菜蕾薹期渍水的缓解效应

以油菜品种秦优7号(敏感)和苏油4号(耐渍)为材料,通过盆栽试验研究吲哚乙酸(IAA)对油菜蕾薹期渍水的缓解效应。蕾薹期渍水持续10d,渍水结束后,叶面喷施浓度为0.1mmol/L的IAA,随后的0~15d调查油菜的生理变化。结果发现:渍水后生物量和叶片光合色素含量降低;谷胱甘肽、抗坏血酸含量和超氧化物歧化酶活性升高;丙二醛含量升高;蔗糖合成酶、蔗糖磷酸合成酶活性上升,蔗糖和可溶性糖含量增加。渍水结束后喷施IAA,对敏感的秦优7号缓解效应更明显;叶片中的光合色素含量升高,5d后显著恢复生长;蔗糖磷酸合成酶活性降低,降低蔗糖含量;蔗糖合成酶活性降低,减少蔗糖的分解;尤其是喷施15d后IAA对渍水胁迫的缓解作用最明显,苏油4号根干重显著增加,而秦优7号的根干重和茎干重均显著增加。叶面喷施IAA有效缓解单株角果数、每角粒数和产量的降低,但对抗氧化系统影响较小。     

南瓜种质资源遗传多样性的SRAP分析

本研究应用SRAP分子标记技术对所收集的85份南瓜资源进行亲缘关系分析，从100对引物中挑出17对引物对其进行条带扩增。结果表明：共获得条带200条，差异带有187条，13条条带为所有南瓜品种所共有，多态性比例为93.5％。基于SRAP数据通过Ntsys2.10e软件计算出85份南瓜资源的遗传相似系数在0.450 0～0.985 0。通过聚类分析将所收集的南瓜资源分为3大类：中国南瓜、印度南瓜、美洲南瓜，亲缘关系较近的是中国南瓜与美洲南瓜，二者与印度南瓜的亲缘关系较远。     

毛豆套种黄秋葵高产栽培措施试验

研究毛豆套种黄秋葵模式中黄秋葵不同种植方式、种植时期、种植密度对黄秋葵产量及毛豆产量的影响,结果表明:黄秋葵种植时间以4月15日至5月1日较好,种植方式选择育苗移栽、种植密度3000~4000株为宜,上述综合措施处理的黄秋葵产量和成品率均较高,且对毛豆产量没有明显影响。     

迷宫景观设计与应用研究

迷宫景观是西方传统的造园形式,在西方园林中有着悠久的历史和深远的文化内涵。随着景观设计领域不断地延伸和拓展,近几年,迷宫也在国内景观设计中相继出现,受到人们青睐。着重对迷宫概念和发展历程梳理总结,并对其构成要素、设计形式进行深入研究,分析其应用现状,为今后迷宫景观的营造提供理论基础。     

椰子组培研究四十年

组织培养对于椰子快速繁殖以及全球椰子产业发展具有重要意义。本文就40年来国内外在椰子组培快繁技术,包括椰子组培技术的重要性,不同外植体如胚芽、花序、子房等在组织培养中的应用与优劣,不同培养基和培育环境对组培效果的影响等要素,进行了详细的总结和讨论。同时总结了椰子组培快繁技术的进展,分析了目前限制椰子组培快繁技术发展的因素,提出了应对策略与具体建议。本文对椰子快繁技术及椰子种质资源保存具有参考价值。     

不同固定条件对几种植物样品超微结构的影响

为比较几种固定条件对不同植物材料样品电镜超微结构图像清晰度的影响。以3个不同科属4种植物[油棕(Elaeis gineansis Jacq.)、拟南芥(Arabidopsis thaliana.)、花生(Arachis hypogaea Linn.)、柱花草(Stylosanthes guianensias Sw.)]为研究主体代表,探讨了2.5%戊二醛与4%戊二醛固定过夜、锇酸固定2 h及过夜的制备方法对其叶片超微结构的影响,并成功观察了柱花草接种胶苞炭疽野生型菌株CH008后的病菌侵入过程。结果表明:油棕、拟南芥、花生及柱花草叶片经4%戊二醛与1%锇酸固定液固定过夜,其组织成像的效果均较为理想,各种细胞器整体信息丰富、结构组织完好、线条清晰。表明,此制备方法能够较好的保存植物叶片和细胞组织,提高制样的成功率及观察分辨率。     

茉莉花茶加工技术与吸香机理研究现状

为了进一步综合地认识茉莉花茶窨制的工艺本质、完善茉莉花茶窨制技术,本文综述和分析了茉莉花茶加工技术及吸香机理的研究现状,并对后续研究进行了展望。