应用组织培养技术快速繁殖香荚兰     

崔元方  刘荣维  麦小燕  梅庆超  邱进祥  陈幸华 《热带作物学报》1988,(2)

比较系统地研究了香荚兰的组织培养技术。通过“丛生芽的诱导”和“微型扦插”年增殖可达千倍以上。比较了不同细胞分裂素对香荚兰增殖率的影响。以培养50天的增殖率计,氨基嘌呤(6-BA)的效果最佳(279.5％),玉米素(Zea)次之(206.8％),激动素(KT)效果最差(140％)。以2毫克/升浓度的BA增埴率最高。香荚兰容易生根,几种生长素对香荚兰都有促根作用。以吲哚丁酸(IBA)的效果最佳,培养17天生根率达100％,吲哚乙酸(IAA)次之(86.7％),NAA更次之(71.4％)。对照不加生长素最差(57.1％)。IBA以0.5毫克/升浓度的处理效果最好。  相似文献   

苍蝇对杧果的传粉作用及其与温度的关系     

朱建华  欧世金  麦福珍  何全光  徐宁  彭宏祥 《热带作物学报》2006,27(4)

通过架设防虫网、人工养蝇、引蝇访花并选择不同天气类型观察苍蝇、蜂和其他种类昆虫在杧果(Mangifera indica)花穗上的活动情况,研究杧果传粉的主导因子、人工养蝇和引蝇访花对提高杧果授粉受精率的效果,以及在不同天气类型情况下温度对主要传粉昆虫苍蝇访花活动的影响。结果表明,杧果主要传粉媒介为昆虫,其中苍蝇在杧果传粉中起主要作用,其次为蜂。苍蝇在杧果花穗上的活动主要受温度影响,不同天气类型对苍蝇访花活动也有影响,在晴天天气条件下苍蝇在花穗上的活动时间和温度范围都较大。人工养蝇和引蝇访花可大幅度提高杧果受精发育果的比例。  相似文献   

More about the potato nematode,Heterodera rostochiensis Woll., in Peru     

Maria Mayer de Scurrah  W. F. Mai  R. L. Plaisted 《American Journal of Potato Research》1973,50(2):58-61

Thirteen resistant selections ofS. tuberosum hybrids bred in the U.S.A. and Europe and 44 diploid clones derived fromS. vernei, S. spegazzinii, S. neohawkesii, andS. sanctaerosae each with resistance to one or more pathotypes ofH. rostochiensis were tested for their resistance to three Peruvian populations of this nematode. Only one diploid clone ofS. sanctatrosae was found to be resistant to the three populations of nematodes, but several clones were resistant to one or another of the nematode populations. More clones were found to resist the nematode population collected near Cuzco than those populations collected near Huancayo or Otuzco. Morphometric measurements of body length, stylet length, and distance of median valve to excretory pore, of second stage larvae showed great variation and no clear difference among the three populations. The measurements obtained were closer to pathotype E from England than to any other recognized pathotypes.  相似文献   

杧果种质资源若干植物学数量性状评价指标探讨   总被引：2，自引：0，他引：2  

朱敏  陈业渊  高爱平  麦贤家 《热带作物学报》2009,30(12):1718-1724

为建立或完善中国数量化、规范化的杧果种质资源描述系统,以便更好地为中国杧果种质资源的研究工作服务,2007～2009年7月,在海南儋州市中国热带农业科学院热带作物品种资源研究所杧果种质圃内进行杧果品种(种质)资源的叶片长度、叶片宽度、叶柄长度、花序长度、花序宽度、花直径、果实纵径、果实横径、果实侧径、核长度、核宽度和核厚度等12项植物学数量性状指标的测定.结果表明, 12个数量性状均存在10%以上的变异系数,叶柄长度、果实纵径和果核长度呈偏态分布,其他9项呈正态分布.根据分析结果,提出了性状分级标准,建议将12个植物学数量性状分为1～5个等级,每个等级提出2个参照品种,1个国外品种,1个国内品种.该研究为中国杧果种质资源描述系统数量化、规范化的建立或完善奠定基础.  相似文献   

不同品种宁夏枸杞果实糖积累差异的生理原因   总被引：2，自引：0，他引：2  

郑国琦  罗霄  买立芸  王俊 《农业科学研究》2009,30(1)

以宁杞1号和宁杞3号枸杞品种为材料,分别对2个品种的果实单粒鲜质量、横纵径、糖含量、淀粉含量及蔗糖代谢相关酶活性的变化进行测定,并对果实糖积累的差异进行研究.结果表明:果实发育过程中,2个品种的果实单粒鲜质量均持续增长,但增长速度不同;与宁杞1号不同,宁杞3号在果实发育后期其横径仍大幅增长;2个品种的果实均以积累己糖为主,在发育过程中己糖含量总体均呈递增趋势,但糖的积累量存在较大差异;果实中转化酶活性的高低是影响其糖分构成的主要原因;2个品种果实品质的差异主要是由果实中糖分含量和种类差异造成的.  相似文献   

饲料水分的快速测定方法   总被引：2，自引：0，他引：2  

麦肇伦 《广东饲料》2000,9(4):5-5

国标法（ＧＢ６４３５ -８６）测定饲料中水分的含量结果准确 ,但时间较长。本实验方便快捷 ,而且可节约成本 ,对中小型企业有一定的实用价值。１说明本实验的仪器设备、试样选取和制备、结果计算等全部与国标法相同 ,所测试样全部为本厂生产的饲料成品或进货的饲料原料。２测定步骤洁净称样皿 ,在１３０±２℃烘箱中烘１ｈ ,取出 ,在干燥器中冷却３０ｍｉｎ ,称准至０ ０００２ｇ,再烘干３０ｍｉｎ ,同样冷却 ,称重 ,直至两次重量之差小于０ ０００５ｇ为恒重。用已恒重称样皿称取两份平行试样 ,每份２～５ｇ（含水重０ １ｇ以上 ,样品厚度…  相似文献   

Relationship between the ultrasonographic findings of suspected superficial digital flexor tendon injury and the prevalence of subsequent severe superficial digital flexor tendon injuries in Thoroughbred horses: a retrospective study     

Mai IIMORI  Norihisa TAMURA  Kazuhiro SEKI  Yoshinori KASASHIMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(2):261

The onset of severe injury to the superficial digital flexor tendon (SDFT) is extremely difficult to predict from slight changes in ultrasonographic findings in cases with no apparent clinical signs. This study investigated the relationship between an increased cross-sectional area (CSA) or edema in the subcutaneous tissue around the tendon and the subsequent onset of severe SDFT injury in Thoroughbred racehorses. Horses were classified into three groups based on ultrasound diagnosis (USD) findings: Group A included cases with enlarged tendons; Group B included cases with tendons of normal size but with prominent edema in the peritendinous tissue; and Group C (control group) included cases with no abnormal USD findings. The incidence of subsequent severe tendon injury was significantly higher in the horses in Groups A (25.7%, 28/101) and B (28.3%, 65/212) than in those in Group C (4.9%, 2/41). There were no significant differences in the median period and the median number of races from the first examination to the subsequent tendon injury between Groups A (140 days, 1 race) and B (120 days, 1 race). The results of this study revealed that horses with increased CSA and peritendinous edema are likely to suffer a subsequent severe tendon injury. Also, these two USD findings, i.e., increased CSA and peritendinous edema, indicate the risk of onset of severe SDFT injury.  相似文献   

Aurasperone A Inhibits SARS CoV-2 In Vitro: An Integrated In Vitro and In Silico Study     

Mai H. ElNaggar  Ghada M. Abdelwahab  Omnia Kutkat  Mohamed GabAllah  Mohamed A. Ali  Mohamed E. A. El-Metwally  Ahmed M. Sayed  Usama Ramadan Abdelmohsen  Ashraf T. Khalil 《Marine drugs》2022,20(3)

Several natural products recovered from a marine-derived Aspergillus niger were tested for their inhibitory activity against SARS CoV-2 in vitro. Aurasperone A (3) was found to inhibit SARS CoV-2 efficiently (IC₅₀ = 12.25 µM) with comparable activity with the positive control remdesivir (IC₅₀ = 10.11 µM). Aurasperone A exerted minimal cytotoxicity on Vero E6 cells (CC₅₀ = 32.36 mM, SI = 2641.5) and it was found to be much safer than remdesivir (CC₅₀ = 415.22 µM, SI = 41.07). To putatively highlight its molecular target, aurasperone A was subjected to molecular docking against several key-viral protein targets followed by a series of molecular dynamics-based in silico experiments that suggested M^pro to be its primary viral protein target. More potent anti-SARS CoV-2 M^pro inhibitors can be developed according to our findings presented in the present investigation.  相似文献   

基于注意力机制神经网络的荒漠区蒸散量模拟     

齐建东  买晶晶 《农业工程学报》2020,36(22):151-157

该研究对基于注意力机制的长短期记忆（Attention-Based Long Short Term Memory，AT-LSTM）模型对蒸散量（Evapotranspiration，ET）模拟的可行性和有效性进行验证，以提高环境数据缺失情况下的蒸散量模拟精度。基于盐池县2012-2017年的每30 min环境数据，利用不同环境因子组合构建基于注意力机制的LSTM模型，并将其与极限学习机（Extreme Learning Machine，ELM）模型、支持向量机（Support Vector Machine，SVM）模型、长短期记忆（Long Short Term Memory，LSTM）模型在日尺度、月尺度和季节尺度上进行对比分析。结果表明：与其他3种模型相比，当输入环境因子变化时，AT-LSTM模型模拟精度变化很小，模拟效果均较好。当输入空气温度、净辐射、相对湿度、土壤温度、土壤含水率所有环境因子时，基于AT-LSTM模型的模拟效果最好，均方根误差（Root Mean Square Error，RMSE）为0.013 mm/30 min，平均绝对误差（Mean Absolute Error，MAE）为0.006 mm/30 min，相关系数（Correlation Coefficient，R）值为0.905。且无论是从小时尺度、日尺度和月尺度来看，AT-LSTM模型的模拟效果均优于其他3种模型。在环境因子缺失的情况下，净辐射对盐池县ET的模拟贡献程度最大，仅输入净辐射时，AT-LSTM模型模拟得到的RMSE和MAE分别为0.014、0.007 mm/30 min，R为0.892，模型模拟精度较高，AT-LSTM模型模拟精度高，模型稳定性强，对蒸散量模拟预测具有一定的适用性，仅输入净辐射的AT-LSTM模型可以作为环境数据缺失条件下的蒸散量预测模型。  相似文献   

沙枣树胶对红葡萄树提取液抗氧活性保护作用的研究     

伊力哈木·托合迪  买吐孙·买吐肉孜  买买提艾则孜  买买提依明 《中国农学通报》2008,24(6):74-77

该文就沙枣树胶对红葡萄树提取液抗氧性的保护作用及其变化进行了初步研究,结果表明红葡萄树提取液具有极强的抗羟自由基(H0·)能力,而抗超氧阴离子自由基(O-2·)的能力较弱,即在空气中易氧化、抗氧活性迅速降低、消失;当加入沙枣树胶初期,其抗氧性能迅速降低,3d后开始上升,15d后其对超氧阴离子自由基清除率达到30%,60d后对羟自由基清除率达到68%,其后,一直保持稳定.在沙枣树胶的多糖活性成分的作用下,红葡萄树胶的抗氧活性显著增强,稳定性提高.研究结果初步表明,沙枣树胶对红葡萄树提取液的抗氧活性具有显著的保护作用.  相似文献