作物害虫的猖獗与高毒农药的"倾泻"的治理对策

阐述了我国农作物害虫发生现状及化学农药防治的现状，分析了作物害虫猖獗与高毒农药“倾泻”的原因与发展，提出了防止作物害虫猖獗和高毒农药“倾泻”的5条对策，即做好高毒农药危害性的宣传工作，提高农民禁用、限用高毒农药的自觉性；调整农药产品结构，大力发展生物农药；生物农药与化学农药复配，促使高毒农药低毒化；推广转基因作物；推广使用高效、高选择性、低毒、低用量、安全农药。     

EGR降低S195型柴油机排放的试验研究

介绍了排气再循环（EGR）降低S195型柴油机排放的试验及其研究结果。比较了排气再循环率不同评价指标的特点，提出了一种实用、方便测量排气再循环量指标的方法，分析了EGR对柴油机燃烧过程、柴油机动力性、经济性和排放指标的影响。单缸柴油机循环波动影响分析为今后的实际应用提供了依据。     

一种土壤微生物总DNA的高效提取方法

获得高浓度、大片段、多样性程度高的土壤微生物总DNA 是研究土壤微生物群落结构的分子生态学基础。本文采用间接法(菌体细胞回收法)提取红壤地区两种土壤类型的土壤微生物总DNA,定量计算其回收率,并与直接法(细胞原位裂解法)比较了提取效率和纯度。结果表明:红壤地区2种土壤每克干土的总DNA提取量,间接法约为0.34和0.53礸/g干土,直接法约为13.62和24.32礸/g干土;间接法的提取效率低于直接法,但所得DNA片段较大,且Sau 3AⅠ 酶切和16 S rDNA通用引物PCR扩增结果显示,间接法比直接法更能有效地去除土壤中的某些抑制剂,所得总DNA的纯度更高,有利于后续操作。     

适应农业产业发展产教融合课堂教学改革研究

本文对适应农业区域产业发展产教融合课堂教学改革进行了一定的研究,希望可以为“产教 结合、校企一体”的发展之路提供一定的参考价值。     

毛细管气相色谱法同时测定苹果 梨中氯氰菊酯联苯菊酯和氟氯氰菊酯的残留量

利用乙腈提取、氧化铝和弗罗里硅土填料净化的前处理方法,研究了采用毛细管气相色谱同时测定苹果、梨中氯氰菊酯、联苯菊酯和氟氯氰菊酯残留量的方法。结果表明,用20mL10%丙酮/石油醚作为淋洗液,0.5mg·L-1水平时苹果、梨在两种填料的回收率都在90%—120%之间;在0.05mg·L-1水平时,苹果、梨在弗罗里硅土柱上,3种菊酯都达到了90%—110%的满意结果;而在氧化铝柱上,只有联苯菊酯和氟氯氰菊酯达到90%—110%的结果,氯氰菊酯只达到64.8%和61.5%的结果。综合考虑,利用弗罗里硅土柱对这3种菊酯的净化效果较好,高低浓度均符合农药残留分析的要求。     

高活性促性腺激素类似物及其复配制剂在鱼类人工繁殖中的应用

通过催产试验,在高活性促性腺激素类似物相互之间、在类似物与ＨＣＧ之间、在类似物同ＨＣＧ或ＨＷＨＯ复配而成的复配制剂相互之间、在类似物与其复配制剂之间,进行了催产效果的对比。结果表明,各种类似物对不同鱼类的催产效果各不相同;类似物的催产效果明显优于ＨＣＧ;使用类似物复配制剂,其催产效果优于单独使用ＨＣＧ或类似物。     

无核优质丰产椪柑新品系——黔阳无核椪柑的选育

1991年从湖南省黔阳县普通柑中选育出来的优良芽变新品系———黔阳无核柑 ,经 8年继代高接繁殖 5代鉴定及多点栽培试验 ,证明其果实稳定无核 (0～ 0 .0 0 1粒 /果 ) ,果形美观 ,肉质脆嫩 ,汁多化渣 ,风味浓郁 ,品质极优。并表现生长旺盛 ,早果、丰产 ,适应性广。该品种已通过湖南省农作物品种审定委员会审定。根据花粉育性研究及人工授粉试验结果 ,初步认为花粉败育及雌性器官 (胚囊 )可能也高度败育是导致其稳定无核的原因     

Persistence and performance of esfenvalerate residues on broccoli

The efficacy of esfenvalerate (84 g litre-1 EC; Asana XL) at 7.0 g AI ha-1 on broccoli was tested against the flea beetle, Phyllotreta cruciferae Goeze (Chrysomelidae: Coleoptera) and the imported cabbage worm, Pieris rapae L (Pieridae: Lepidoptera) under field conditions. Insect populations were monitored before and after treatment. Periodic sweep-net collections and examination of the leaves in treated and untreated broccoli plots revealed mean reductions of P cruciferae levels of nearly 98% 1 week post-application compared with untreated plots. The residual toxicity of esfenvalerate was also effective for 2 weeks in reducing population density of P rapae by 69% on broccoli leaves. The impact of esfenvalerate on feeding damage to broccoli leaves was established by counting the number of feeding holes made by P cruciferae on spring broccoli and P rapae on fall broccoli. As the leaf area ingested increased, a linear relationship was seen between the number of holes and number of insects. Results indicated that forage destruction by the two pests was significantly reduced by esfenvalerate application. Esfenvalerate was extracted from broccoli at 1 h and 1, 3, 7, 10, and 14 days post-application for residue analysis. Residues on spring broccoli were 12.2, 5.2 and 2.9 micrograms cm-2 on the leaves and 0.13, 0.05 and 0.02 microgram g-1 on the heads at 1 h, 1 and 3 days, respectively. Only trace levels (0.001 microgram g-1) were detected in/on the heads 14 days after spraying. On the basis of half-life (T1/2) values, persistence of esfenvalerate on spring broccoli leaves (T1/2 = 1 day) was shorter than on fall broccoli (T1/2 = 1.6 days). T1/2 values were 2.1 and 3.6 days on spring and fall broccoli heads, respectively. The implications of these residue levels on re-entry times into treated fields are discussed.     

Tissue Culture Response from Seedling Explants of Commercial Barley Cultivars Grown in Bulgaria

Abstract

Only a few studies have been conducted in which regenerability of barley has been examined. In the current study, 17 barley genotypes (nine two-row malting type: Aster, Emon, Ruen, Jubiley, PV101, Körten, Krassi 2, Perun and Igri, and eight six-row feed types: Karnobat, Hemus, Jerun, Veslets, Aheloi 2, Diana, Panagon, and Izrgev) were evaluated for tissue-culture response from seedlings during a three-year period. Regenerable calli were obtained from all tested genotypes. Although there was much variation in regeneration capacity among the cultivars, plants were obtained from all cultivars. The majority of green plants grown to maturity were fertile and normal in appearance. The frequency of embryogénie callus induction and regenerability was influenced by genotype and growth conditions of the donor plants. Genotype was the most important determinant of the in vitro response. The best in vitro performance, based on ability to form regenerable calli and to regenerate plants was observed for Ruen, Aster, and Emon.     

草甘膦防除灌草丛草场灌木的研究

用草甘膦喷洒灌草丛草场灌木和半灌木对其防除效果及再生性进行了试验观察。结果表明，施药浓度０．０５％以上时，半灌木死亡率１００％；浓度０．５％以上时，灌木死亡率８５％以上，７５ｄ后无再生植株，１２０ｄ后，浓度０．５％以上时，无再生植株，浓度０．１５和０．０５％时再生植株分别为１株和３株，占观察数的４％和１２％。