水帘降温对鹅舍内不同位置环境参数的影响

为研究水帘降温系统对鹅舍内环境参数的影响,在设有水帘降温系统的鹅舍内,于风机端、水帘端及中部大门位置分别选取离地０.６、１.２和１.８ｍ９个测量点,测量水帘的开关对温湿度、ＣＯ２、粉尘、总菌数及大肠杆菌（Ｅｓｃｈｅｒｉｃｈｉａｃｏｌｉ）数量的影响．结果表明,水帘系统开启时,环境总体温度不超过３０℃,湿度８５％～９０％,ＣＯ２显著高于关水帘时（Ｐ＜０.０５）,粉尘含量明显低于关闭水帘时;在不同区域内,鹅舍的总细菌和大肠杆菌数量变化趋势相近,均表现为开启水帘时,靠近水帘位置的西端细菌数量较低,且显著低于关闭启水帘时（Ｐ＜０.０５）;在０.６和１.２ｍ处,总细菌和大肠杆菌数量均表现为关闭水帘时高于开启时,且总细菌数量在１.２ｍ处有显著性差异（Ｐ＜０.０５）．试验结果说明,水帘降温系统能有效地控制鹅舍内环境参数.     

影响甘蓝型油菜每角粒数因素分析

为培育高角粒数的油菜品种，研究每角粒数种子（或胚珠）败育对每角果粒数的影响，选取36份双单倍体（DH）材料，采用自然开放和强制自交、杂交、辅助人工授粉等4种处理方式，分别调查各处理中初花时胚珠数和成熟风干角果中正常成熟籽粒和败育种子的数量与形态变化，探寻种子（或胚珠）败育发生原因。结果发现：材料的初始胚珠数为23.05~36.15个，差异极显著。种子成熟后，每角粒数为平均16.80；胚珠数与每角粒数间的相关系数为0.77**；各材料每角粒数占初始胚珠数的百分比为平均56.19%，近44.00%的胚珠在种子发育过程中会发生败育；胚珠数与每角粒数呈正相关；败育是导致每角粒数减少的主要原因。不同材料胚珠数不同，胚珠数与材料基因型有关，败育比率也与材料基因型有关。根据胚珠的直径可将败育类型划分为3种：a类型（直径小于0.1mm）、b类型（直径0.1~1.0mm）、c类型(胚败育)。3种败育类型在36个参试材料和4种试验处理中均有发生，前两种类型败育是胚珠（或种子）败育的主要类型，平均发生概率分别为19.34%和7.91%，胚败育发生概率较低，仅为1.54%。胚珠（或种子）败育现象普遍存在于甘蓝型油菜种子发育过程中，原因可能与花粉和柱头发育、花粉与柱头识别、受精以及胚初期发育异常相关；胚败育可能与胚发育停滞有关。      

云南间作大豆耐荫性综合评价及鉴定指标筛选

      本文旨在探讨不同基因型大豆品种的耐荫特性，筛选出耐荫性鉴定指标，建立可用于耐荫性评价的数学模型。以44个大豆品种（系）为试验材料，在玉米-大豆间作下创设的自然荫蔽条件开展耐荫性鉴定，净种大豆作为对照。在各参试材料植株成熟期调查10个主要形态性状和产量性状，以各指标的耐荫系数为基础，采用多元统计方法对大豆的耐荫性进行综合评价。结果表明：与对照相比，受荫蔽胁迫后，参试材料的各性状变化趋势及幅度不同，各指标间都有不同程度的相关性，部分性状间相关性达到显著或极显著水平。通过主成分分析，将10个单项指标转换为4个相互独立的综合指标，代表了全部数据79.77%信息量。利用隶属函数法计算综合耐荫评价值（D），并对其进行系统聚类，将44个大豆品种（系）按照耐荫性强弱分为了强耐荫、中等耐荫和弱耐荫3大类。通过逐步回归建立了大豆耐荫性评价数学模型，并筛选出株高、主茎节数、有效分枝数、单株荚数、单株粒数、单株产量、每荚粒数和倒伏8个性状可作为云南省间作大豆耐荫性鉴定指标     

20%氨氯·二氯·烯草酮可分散油悬浮剂防除油菜田杂草的效果

     为明确新型吡啶类和环己烯酮类除草剂复配制剂对油菜田杂草的防控效果，指导新型除草剂在油菜田的合理使用，通过田间试验研究了20%氨氯吡啶酸?二氯吡啶酸?烯草酮可分散油悬浮剂对油菜田主要杂草的防除效果，以及杂草防除后对田间光照和杂草氮、磷、钾及水分累积的影响。试验结果表明，施用20%氨氯吡啶酸?二氯吡啶酸?烯草酮可分散油悬浮剂防除油菜田杂草效果显著，对菵草、大巢菜、看麦娘、牛繁缕等单双子叶杂草均有良好防效，总草鲜重防效可达88.7%～98.0%，显著优于两种对照药剂。杂草防除后，显著降低了杂草对田间氮、磷、钾和水分的消耗，有效地改善了田间光照和水肥条件。20%氨氯吡啶酸?二氯吡啶酸?烯草酮可分散油悬浮剂处理的油菜产量达到2 626.26～2 836.26 kg/hm2，增产效果显著，产量较空白对照增加18.2%～27.9%，增收2 173.5～3 307.5元/hm2。研究结果表明，20%氨氯吡啶酸?二氯吡啶酸?烯草酮可分散油悬浮剂在油菜田有良好的应用前景，推荐剂量为每公顷使用有效成分225～300g。     

油菜籽叶绿素含量近红外光谱快速检测

        油菜机械化收获的油菜籽叶绿素含量不一致，直接影响其加工成本和菜籽油品质，亟需建立成熟期油菜籽中叶绿素快速无损检测技术。本文采用紫外可见分光光度法测定450份代表性油菜籽样品中叶绿素含量，并采集近红外光谱数据。通过一阶导数、标准正态变量变换预处理，采用竞争性自适应重加权采样算法进行波长选择，建立了油菜籽中叶绿素含量偏最小二乘法回归模型。交互检验结果显示，油菜籽中叶绿素含量预测模型的验证集决定系数为0.9446，交叉检验均方根误差(RMSECV)为1.36mg/kg。研究表明，该方法可以准确预测油菜籽中叶绿素含量，为油菜籽品质快速监测提供了重要的技术支撑。     

植物种质资源的超低温保存

超低温保存是目前植物种质资源长期稳定保存的理想方法。超低温保存成功的关键在于避免降温及化冻过程中的细胞内结冰,材料特性、冷冻前的预培养、冷冻保护剂、降温冰冻方法和化冻及再培养等因素共同决定了超低温保存的效果。近年来随着科学研究的不断深入,超低温保存取得了一些令人鼓舞的进展,如被成功保存的植物材料日益增多,发现了新型冷冻保护剂抗冻蛋白,玻璃化、包埋玻璃化等新的冰冻保存方法相继建立,生活力测定、恢复培养活力测定以及保存后遗传性状的分析和检测等技术得到了更新与发展。但作为低温生物学中比较新的领域,超低温保存还有许多问题需要进一步研究探讨。     

Educated consumers don’t believe artificial meat is the solution to the problems with the meat industry

The production of in vitro meat by cell culture has been suggested by some scientists as one solution to address the major challenges facing our society. Firstly, consumers would like the meat industry to reduce potential discomfort of animals on modern farms, or even to avoid killing animals to eat them. Secondly, citizens would like meat producers to reduce potential environmental deterioration by livestock and finally, there is a need to reduce world hunger by increasing protein resources while the global population is predicted to grow rapidly. According to its promoters, artificial meat has a potential to make eating animals unnecessary, to reduce carbon footprint of meat production and to satisfy all the nutritional needs and desires of consumers and citizens. To check these assumptions, a total of 817 educated people(mainly scientists and students) were interviewed worldwide by internet in addition to 865 French educated people. We also interviewed 208 persons(mainly scientists) after an oral presentation regarding artificial meat. Results of the three surveys were similar, but differed between males and females. More than half of the respondents believed that "artificial meat" was feasible and realistic. However, there was no majority to think that artificial meat will be healthy and tasty, except respondents who were in favour of artificial meat. A large majority of the respondents believed that the meat industry is facing important problems related to the protection of the environment, animal welfare or inefficient meat production to feed humanity. However, respondents did not believe that artificial meat will be the solution to solve the mentioned problems with the meat industry, especially respondents who were against artificial meat. The vast majority of consumers wished to continue to eat meat even they would accept to consume less meat in a context of increasing food needs. Only a minority of respondents(from 5 to 11%) would recommend or accept to eat in vitro meat instead of meat produced from farm animals. Despite these limitations, 38 to 47% of the respondents would continue to support research on artificial meat, but a majority of them believed that artificial meat will not be accepted by consumers in the future, except for respondents who were in favour of artificial meat. We speculated that the apparent contradictory answers to this survey expressed the fact that people trust scientists whoare supposed to continuously discover new technologies potentially useful in a long term future for the human beings, but people also expressed concern for their health and were not convinced that artificial meat will be tasty, safe and healthy enough to be accepted by consumers.     

丰产抗病抗倒大豆新品种沧豆11选育

大豆新品种沧豆11是沧州市农林科学院2005年以鲁99-1为母本,沧豆4号为父本进行有性杂交,经系谱法选育而成。2019年通过河北省农作物品种审定委员会审定。该品种在河北省区域试验中平均产量3199.5kg/hm^2,蛋白质含量39.85%,脂肪含量20.5%,抗SC3和SC7,全生育期107.4 d,适宜在河北省中南部夏播区域种植。介绍了沧豆11的选育经过及主要栽培技术。     

绿肥翻压对烟地红壤微生物及土壤养分的影响

为探讨绿肥对烟地红壤改良培肥的生物机制,试验以冬闲地为对照,研究了紫花苕绿肥翻压及麦茬翻压对烟地红壤微生物、土壤酶活性及养分含量的影响。结果表明,绿肥翻压处理的土壤细菌、放线菌、土壤酶活性、土壤有机质及养分含量均高于麦茬翻压地和冬闲地,变化差异达到显著(p<0.05)或极显著水平(p<0.01),而真菌数均以麦茬地较高。绿肥翻压地分别与麦茬翻压地和冬闲地比较:在越州试验区的土壤细菌分别提高1.74×106、2.61×106cfu.g-1,放线菌提高1.35×104、0.65×104cfu.g-1,土壤脲酶提高1.5、1.68 mg.g-1,酸性磷酸酶提高2.9、3.09 mg.g-1,过氧化氢酶提高1.2、2.54 mL.g-1,多酚氧化酶提高1.91、7.58 mg.kg-1,土壤有机质提高16.36、26.22 g.kg-1,土壤碱解N提高42.52、54.31 mg.kg-1,土壤速效磷(P2O5)提高6.22、7.57 mg.kg-1;在晋宁试验区的土壤细菌分别提高2.52×106、3.95×106cfu.g-1,放线菌提高1.17×104、1.62×104cfu.g-1,土壤脲酶提高1.77、2.0 mg.g-1,酸性磷酸酶提高1.13、1.24 mg.g-1,过氧化氢酶提高1.45、2.19 mL.g-1,多酚氧化酶提高4.81、11.34 mg.kg-1,土壤有机质提高10.18、19.43 g.kg-1,土壤碱解N提高41.34、54.43 mg.kg-1,土壤速效磷(P2O5)提高4.79、5.86 mg.kg-1。     

Low temperature, IBA concentrations and optimal time for adventitious rooting of Eucalyptus benthamii mini-cuttings

Eucalyptus benthamii is a forest species of economic interest that has difficulty with seed production and also is considered to have difficulty with adventitious rooting using propagation techniques,such as cutting or mini-cutting.We aimed to assess the adventitious rooting percentage under different storage times in low temperatures and at various IBA(indole-3-butyric acid) concentrations to determine the optimal time of permanence for rooting Eucalyptus benthamii minicuttings in a greenhouse.Shoots collected from mini-stumps cultivated in a semi-hydroponic system were used to obtain the mini-cuttings.For the first experiment,the mini-cuttings were stored at 4℃ for 0(immediate planting),24,48,72,96 and 120 h.The second experiment evaluated the rooting dynamic to determine the optimal time of permanence for minicuttings in a greenhouse.The basal region of the mini-cutting was treated with various IBA solutions:0(free of IBA),1,000,2,000,3,000 and 4,000 mg·L-1.Every seven days(0(immediate planting),7,14,21 and 28 days),destructive sampling of the mini-cuttings was performed to evaluate the histology of the adventitious rooting.Eucalyptus benthamii minicuttings should be rooted immediately after the collection of the shoots.The 2,000 mg·L-1 IBA concentration induced a greater speed and percentage of adventitious rooting,and an interval of 35 to 42 days was indicated for permanence of the mini-cuttings in the greenhouse.Exposure to low temperature induced adventitious root formation with diffuse vascular connections.