新农科背景下课程思政在农学类专业基础课程教学中的探索

以农学类专业基础课程植物生理学为例,分析了课程思政在专业基础课程教学中的意义,探讨了课程思政融入专业基础课程教学的途径,以期促进农学类专业基础课程课程思政教学效果的提高,为努力培养既有高尚道德情操、又有扎实理论基础、兼有广博国际视野、更有卓越实践能力的知农、爱农新型人才奠定基础。

氟啶虫酰胺对3种水生生物的急性毒性

[目的]了解氟啶虫酰胺对3种水生生物的毒性风险。[方法]在实验室条件下,以斜生栅藻、大型溞和斑马鱼为研究对象,参照《化学农药环境安全评价试验准则》和OECD化学物质对水生生物毒性试验方法,研究氟啶虫酰胺对斜生栅藻、大型溞和斑马鱼的急性毒性。[结果]氟啶虫酰胺对斜生栅藻的48 h-E_(y)C_(50)为77.28 mg/L,72 h-E_(y)C_(50)为60.16 mg/L,对大型溞的24 h-EC_(50)为30.04 mg/L,48 h-EC_(50)为25.27 mg/L,对斑马鱼的48 h-LC_(50)为91.07 mg/L,72 h-LC_(50)为73.91 mg/L,96 h-LC_(50)为73.91 mg/L。根据毒性等级划分标准,氟啶虫酰胺对斜生栅藻、大型溞和斑马鱼的毒性等级均为低毒。[结论]氟啶虫酰胺对水生生物毒性较低,使用安全。

Control Effects of Mixture of Metamifop and Cyhalofop-butyl on Annual Weeds Barnyard Grass in Direct-seeding Paddy Field

In order to explore the control effects of 10% metamifop EC and 20%cyhalofop-butyl OD on barnyard grass(Echinochloa crusgalli(L.) Beauv.) as well as their safety to rice in rice direct-seeding paddy field, field efficacy experiments were carried out in Taoyuan County and Hanshou County of Hunan Province. The results showed that the control effect of different pesticide treatments on barnyard grass was good, and the control effect reached more than 93%. Of which, 10% metamifop EC 2 250 mL/hm^(2)+20% cyhalofop-butyl OD 1 500 mL/hm^(2)had the best control effect,exceeding 99% and each treatment had no significantly ponisonous to rice. However,considering cost-saving and effect-increasing, it was recommended to use 10%metamifop EC 1 050 mL/hm^(2)mixed with 20% cyhalofop-butyl OD 1 050 mL/hm^(2)for the control of barnyard grass, which not only had the effect of controlling barnyard grass, but also was safety to rice.

冷水江段资江水体中阿特拉津残留分析

本研究在资江冷水江段从上游到下游共设置了12个采样点,于枯水期(3月)和丰水期(7月)采集水样,测定水样中阿特拉津残留浓度,以探讨资江冷水江段的阿特拉津残留水平时空变化,并分析该河段水体中阿特拉津的主要来源。结果表明:资江冷水江段阿特拉津的残留水平枯水期为0.235~1.045μg/L、丰水期为0.723~3.742μg/L;阿特拉津的残留水平丰水期大幅高于枯水期,并且从上游到下游大体上呈现出逐渐降低的趋势。资江冷水江段的阿特拉津,丰水期来源包括附近农田输入、上游河流输入、沉降,枯水期的来源主要为上游河流输入。

6%吡蚜酮·氯虫苯甲酰胺缓释剂对二化螟和稻纵卷叶螟的防效研究

为有效防治衡阳县稻田二化螟和稻纵卷叶螟,对6%吡蚜酮·氯虫苯甲酰胺GR进行了田间药效试验,并以50%吡蚜酮WG和20%氯虫苯甲酰胺SC进行了对比分析。结果表明,6%吡蚜酮·氯虫苯甲酰胺GR有效成分量在630、720g(ai)/hm^(2)时,仅需施1次药对水稻二化螟和稻纵卷叶螟均有着较好的防治作用;与需要施2次药的对照药剂20%氯虫苯甲酰胺SC无显著性差异,而50%吡蚜酮WG对二化螟和稻纵卷叶螟无防效。6%吡蚜酮·氯虫苯甲酰胺GR具有防效时间长、防治成本低的特点,大田防治时,建议选择有效成分量为630g(ai)/hm^(2)的6%吡蚜酮·氯虫苯甲酰胺GR防治二化螟和稻纵卷叶螟。

Application of Uniform Design and SVR for Culture Medium Optimization of Organophosphorus Degradation Bacteria

In order to improve the degradation activity of organophosphorus degradation bacterial strains, uniform design and support vector regression(SVR) are used to optimize the formula of mineral salt medium for the strains based on single factor experiment. The formula being used after SVR optimization is glucose 1.24 g/L,NH4 NO3 0.73 g, KH2 PO4 0.96 g, KCl 0.50 g, MgSO4·7 H2 O 0.50 g, MnSO4 0.02 g, CaCl2 0.04 g, distilled water 1 000 mL;the highest degradation rate is obtained at pH7.0(SVR, 76.68%), superior to that of the QSAR model(74.67%). The formula optimization method based on uniform design and SVR is very promising to apply in various multiple-factor and multiple-level formula optimization experiments.

NO诱导IAA和O_(2)·^(-)积累于侧根尖端促进水稻侧根生长

为了探讨NO和超氧阴离子对水稻种子根侧根生长的影响,以DR5-GUS标记IAA的转基因水稻为材料,种子催芽萌发后,用含有不同浓度的NO供体、NO合成酶抑制剂和清除剂溶液来培养萌发3 d的水稻幼苗,在培养的第3 d和第5 d分别测量初生根长度和初生根上侧根数量,并通过DAF-2DA对NO、GUS对IAA和NBT对超氧阴离子(O_(2)·^(-))染色后,在显微镜下观察NO、IAA和O_(2)·^(-)在侧根的定位,分析与NO合成相关的基因表达。结果表明,NO和IAA主要分布在根中柱的维管束部分以及侧根起始形成处和侧根根尖,O_(2)·^(-)只极性分布在侧根起始部位和侧根根尖。当NO合成受到抑制或清除时,NO、IAA和O_(2)·^(-)在侧根的积累量明显减少,侧根数量及初生根长度也均显著下降。荧光定量PCR分析发现,外源的NO供体SNP处理均能显著诱导水稻OsNIA1和OsNIA2基因表达,而NO合成酶抑制剂处理则抑制OsNIA1和OsNIA2基因表达。基于我们的实验结果,NO作为一种重要的信号物质参与初生根和侧根的生长,并需IAA和O_(2)·^(-)极性积累于侧根的起始部位,从而达到促进侧根的形成,当NO合成受阻时初生根和侧根生长均受到抑制。