2种低毒杀虫剂防治水稻粘虫示范试验

为合理使用低毒农药防治水稻粘虫,2015年7月在广西乐业县同乐镇和甘田镇进行25%灭幼脲悬浮剂和2.2%甲氨基阿维菌素苯甲酸盐微乳剂防治粘虫大田示范试验。结果表明:施药后17 d,核心区25%灭幼脲对粘虫的防治效果和保叶率分别为96.19%和94.73%,在培训指导农民防治示范区的防效分别为93.50%和95.10%;施药后10 d,核心区2.2%甲氨基阿维菌素苯甲酸盐对粘虫的防治效果和保叶率分别为96.61%和97.35%,在培训指导农民防治示范区的防效分别为90.07%和89.59%。25%灭幼脲和2.2%甲氨基阿维菌素苯甲酸盐处理区对粘虫的防效均要高于农民自防区。     

草地贪夜蛾幼虫龄期对自相残杀行为的影响

对群体饲养下草地贪夜蛾幼虫在不同龄期的自相残杀行为进行了比较研究,结果表明:在4种密度(5、10、20头/瓶和30头/瓶)下,不同龄期的幼虫自相残杀率差异显著,不同密度下的自相残杀行为主要集中在5龄幼虫,其自相残杀率均在5龄第2天时最高,在5、10、20和30头/瓶中分别为(14.34±3.28)%、(17.94±3.26)%、(18.21±3.47)%和(27.05±5.52)%,幼虫在5龄前的自相残杀行为并不明显。进一步测定发现,相同数量的4龄和5龄幼虫混合后在3种密度(4、10和20头/瓶)下的自相残杀率无显著差异(F=2.29,df=2,P>0.05),但随着幼虫密度的增加,死亡的4龄幼虫占总死亡个体的比例升高,而死亡的5龄幼虫所占比例下降。这说明草地贪夜蛾同一龄期的幼虫自相残杀行为具有明显的龄期依赖性,自相残杀行为主要发生在高龄幼虫间。低龄和高龄幼虫同时存在时低龄幼虫被残杀的比例较高。试验结果对于草地贪夜蛾的室内大量饲养具有一定借鉴作用。     

Cepharanthine induces autophagy via PI3K/AKT/mTOR signaling pathway in ovarian cancer SKOV3 cells

AIM: To investigate the autophagy of human ovarian cancer SKOV3 cells induced by cepharanthine and to explore its mechanism. METHODS: The effect of cepharanthine on the viability of ovarian cancer SKOV3 cells was measured by CCK-8 assay. The SKOV3 cells were treated with cepharanthine, and then the formation of autophagosome was observed with acridine orange staining under fluorescence microscope. The protein levels of LC3, AKT, p-AKT, mTOR, p-mTOR and GAPDH in the SKOV3 cells treated with cepharanthine were determined by Western blot.RESULTS: Cepharanthine significantly inhibited the viability of ovarian cancer SKOV3 cells in a dose-dependent manner (P<0.05). The number of the intracellular acidic autophagosomes with bright red fluorescence was significantly increased after cepharanthine treatment in the SKOV3 cells. The expression of LC3-Ⅱ in SKOV3 cells was significantly enhanced after cepharanthine treatment. Furthermore, treatment with cepharanthine in the SKOV3 cells also resulted in a significant down-regulation of phosphorylated form of AKT and mTOR (P<0.01), while the total protein level was not changed. Combination of cepharanthine and 3-methyladenine resulted in a substantial decrease in the cell viability compared with using cepharanthine alone.CONCLUSION: Cepharanthine significantly inhibits the growth of human ovarian cancer SKOV3 cells and induces the autophagy, which may be correlated with down-regulation of PI3K/AKT/mTOR signaling pathway.     

不同施氮量对盐碱地水稻产量及品质的影响

以南粳9108为试验材料,研究了施氮量对盐碱地水稻产量及品质的影响。结果表明,在一定范围内,水稻产量随着施氮量的增加而增加,在施氮量为20 kg/667 m~2时产量最高;盐碱地条件下,增施氮肥会增加稻米的垩白粒率、垩白度和蛋白质含量,降低直链淀粉含量;此外,施氮量的增加还会显著降低稻米的蒸煮品质与食味品质。     

Silage and total mixed ration hygienic quality on commercial farms: implications for animal production

Implications of silage hygienic quality for animal production were investigated on forty‐five dairy farms in South West England. Samples of grass and maize silages and of total mixed rations (TMR) were obtained together with information on silage technology, herd size and animal production. Samples were analysed for mycotoxins, bacteria, yeasts, moulds and chemical composition. Thirteen mycotoxins were assayed, but none were detected in the samples of grass silage. However, mycotoxins were found in 0·9 of all maize and other silage samples, with deoxynivalenol and zearalenone predominating. There was no relationship between total mycotoxin concentration and mean lactation milk yield per cow. Enterobacteria counts tended to be higher in maize silage than in grass silage and higher still in TMR – a cause for concern. There were no relationships between mould counts and mycotoxin concentrations in silages, implying that mycotoxins may have been produced in the field pre‐ensiling.     

超高效液相色谱—串联质谱法检测鸡血液样品中喹诺酮类药物残留

旨在建立鸡血液样品中多种喹诺酮类药物残留的超高效液相色谱—串联质谱方法。样品经乙腈提取,经Waters Acquity UPLC BEH C₁₈色谱柱分离,以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱,电喷雾正离子（ESI⁺）模式电离,MRM扫描模式检测。经方法学验证,该方法的线性关系、回收率、精密度均符合要求。应用超高效液相色谱—串联质谱法建立了鸡血液样品中多种喹诺酮类药物同时检测的方法,实现了动物血液样品中12种喹诺酮类药物同时定性、定量分析。     

中国粮食进口安全综合评价研究——基于超效率DEA模型

在对粮食及粮食进口安全内涵加以界定的基础上,从粮食数量、粮食质量、粮食价格、粮食贸易、国家经济、生态环境6个方面分析中国粮食进口安全的影响因素,基于超效率DEA模型构建中国粮食进口安全评价模型。对1992—2015年中国粮食进口安全状况进行评价,结果表明,1992—2015年中国粮食进口处于安全状态,粮食进口对我国粮食价格安全和生态安全的影响程度较小,对数量安全、质量安全、贸易安全和经济安全的影响程度较大。     

中稻大田机插与手工插秧简比试验

水稻机械化插秧能够大幅度提高劳动生产率,减轻劳动强度,降低生产成本,达到增产增收的效果。试验结果表明:水稻机插栽培有效穗数多,有利于形成较为合理的群体结构,从而穗粒数较多,结实率提高,产量高,增产效果明显。     

广东主要品种(品系)工夫红茶适制性分析

对广东省农业科学院茶叶研究所培育的具有代表性的品种(品系)进行工夫红茶适制性分析,结果表明,不同的品种(品系)优势各不相同,但大体上都具有较高的水浸出物和氨基酸含量,揭示了各个品种(品系)的特点,为今后优异红茶品种的选育提供依据和参考。     

分流叶片对高速井泵压力脉动的影响

针对高速井泵采用分流叶片设计带来的稳定性问题,运用Creo3.0软件建立了叶轮、导叶等关键零件的三维模型;在CFX数值模拟数据与外特性试验数据吻合较好的基础上,将分流叶片的进口直径d₁与叶轮外径D₂的比值定义为一个表达分流叶片综合特性参数的量纲一化系数σ.σ分别取值0.60,0.62,0.65,设计分流叶片长短不同的3个叶轮方案,且对各方案的动静干涉区域进行了详细的压力脉动数值模拟计算及分析.结果表明:压力脉动幅值大小与监测点和交界面的径向距离有关,径向距离越大,压力脉动幅值越小;各监测点压力脉动随分流叶片长度的减小逐渐减弱,当分流叶片长度减小到某一临界值以后,压力脉动基本保持不变;当σ=0.62时,压力脉动幅值较小,脉动周期清晰;除中流线上的监测点以外,各监测点压力脉动主频受叶轮叶频的影响较大,分流叶片对中流线上监测点的压力脉动影响较大.