大蒜精油对灰茶尺蠖的室内毒力及田间防效

采用大蒜精油对灰荼尺蠖进行了室内及田间药效试验,结果表明大蒜精油对灰茶尺蠖的致死中浓度(LC50)为1038.60 mg/L,50％大蒜精油100～250倍液对灰荼尺蠖低龄幼虫具有良好的速效性和持效性,建议生产中可在灰茶尺蠖1～2龄幼虫发生期喷施100～250倍液大蒜精油.这一结果为开发大蒜精油作为茶树主要害虫的新型低...     

燃油植物橡胶树籽的开发利用

橡胶树是中国重要的经济树种,广泛种植于云南和海南等热带区域。橡胶籽是橡胶树的重要副产品,其种仁营养价值高;其中,粗蛋白含量约25%~30%,且必需氨基酸组成较平衡;粗脂肪含量为50%,且橡胶籽油成分近似于亚麻籽油,富含α-亚麻酸,其含量为花生油和葵花油的数十倍。橡胶籽中含有氢氰酸等抗营养因子,但经贮存、加热可钝化绝大部分氰化物。可见,橡胶籽及其加工产品可作为养殖动物饲料原料。前期研究发现：水产饲料中添加一定比例橡胶籽饼对鱼类生长和健康无明显负面影响,但高比例添加会对鱼类消化和健康产生一定负面影响,其可能与橡胶籽饼中高含量粗纤维有关;橡胶籽饼中赖氨酸和蛋氨酸含量相对较低,使用时应注意补充赖氨酸和蛋氨酸。橡胶籽油富含α-亚麻酸,是鱼油的优质替代源,可部分甚至完全替代水产饲料中的鱼油。本文综述了橡胶籽产品的营养价值及其在水产饲料中的应用现状,可为橡胶籽的开发利用提供理论基础。     

丸粒化处理对胡麻种子萌发和幼苗生长的影响研究

采用二因素裂区设计,以保水剂和活性炭、硅藻土、凹凸棒为填充剂的包衣材料制作丸粒化胡麻种子,研究了丸粒化处理对胡麻种子萌发和幼苗生长的影响。结果表明:与不加保水剂相比,保水剂质量与种子质量为1∶1时,丸粒种子的活力指数和出苗率显著提高20.11%、18.62%;随着保水剂含量的增加,幼苗的根冠比显著减小3.25%。包衣剂中以活性炭:凹凸棒=1∶1为填充剂的发芽率和出苗率比不加填充剂的明显提高6.79%、22.41%,幼苗生长最健壮。与未丸粒化的种子相比,当保水剂质量与种子质量为1∶1时,以活性炭:凹凸棒=1∶1为填充剂的丸粒种子发芽指数、活力指数和出苗率显著提高,而且幼苗的茎粗、叶面积和根冠比分别显著增加11.02%、27.35%、28.07%。可见,适量的保水剂(保水剂质量与种子质量为1∶1)和以活性炭、凹凸棒为填充剂的包衣剂能提高胡麻种子活力,增加出苗率,使幼苗的干物质重增大,根系发达,根冠比提高,为胡麻高产奠定了良好的基础。     

4%嘧菌酯·噻呋酰胺展膜油剂防治水稻纹枯病田间药效初探

展膜油剂是一种专为省力化施药研制的农药剂型。为明确新药剂4%嘧菌酯·噻呋酰胺展膜油剂对水稻纹枯病的防治效果,分别在河北省、湖北省、湖南省及上海市选取8地进行了2年田间药效试验,比较了不同剂量处理间的防治效果。结果表明,4%嘧菌酯·噻呋酰胺展膜油剂对水稻纹枯病具有较好防效,优于对照药剂25%嘧菌酯悬浮剂及240g/L噻呋酰胺悬浮剂防治效果,且使用方便。当施药量达到200mL/7667m^2时,2014年,在河北省、湖北省、湖南省及上海市,药后14d防效分别为82.41%、89.2%、83.25%及95.29%;2015年,在河北省、湖北省、湖南省试验地,药后14d防效分别为81.72%、81.95%、90.9%;两年防效均优于或持平于对照药剂。最佳施药量为200mL/667m^2.     

Influence of alkyl oleates on efficacy of phenmedipham applied as an acetone:water solution on Galium aparine

Galium aparine plants were treated at the two-whorl stage with technical-grade phenmedipham. The active ingredient was applied at 10 doses as an acetone:water solution, without emulsifier, alone or in mixture with an ester of oleic acid (methyl, butyl, octyl, dodecanyl, octadecanyl). The plant response was described by a log-logistic regression model. Phenmedipham applied alone did not kill the plants even at the highest dose (1621 g a.i. ha⁻¹). In contrast, addition of any alkyl oleate to phenmedipham killed the plants at the 200–400 g a.i. ha⁻¹ doses. The alkyl oleates differently affected activity of phenmedipham. Their effects could be ranked as follows: butyl ≥ methyl; octyl> methyl; dodecanyl ≤ methyl; octadecanyl < methyl oleate. Thus, butyl and octyl oleate promoted phenmedipham activity more than methyl oleate.     

芦笋种子研究进展

芦笋是一种食药同源的高档蔬菜,20世纪芦笋由欧洲传入中国,70年代初形成规模种植。目前,我国栽培面积和出口量均超过世界总量的50%。近年来,国内外对芦笋育种、栽培、药理、采收加工等方面已有很多研究,但对芦笋种子的研究相对较少。该研究对芦笋种子形态特征、化学成分、生物学特征、抗性特征以及种质资源评价与鉴定等方面进行了综述,以期为更好的研究利用提供参考。     

油料树种风吹楠播种繁殖试验

对热带油料树种风吹楠的播种繁殖试验结果：风吹楠整个果实土壤播种萌发率高达90.52%,种子土壤和沙床播种萌发率分别为68.75%和64.81%,但整个果实沙床播种萌发率仅为12.64%。整个果实和种子的土壤播种苗都生长良好,生长量无明显差异。     

不同轮作序列对旱地胡麻土壤有机碳稳定性的影响

为了探索陇中黄土高原半干旱丘陵沟壑区胡麻轮作序列对土壤碳库的影响,2012-2016年通过4年定位试验,以连作为对照,研究了不同胡麻频率下的轮作序列(F:休闲;PWFW:25%Flax、马铃薯-小麦-胡麻-小麦;WFWP:25%Flax、小麦-胡麻-小麦-马铃薯;FWPF:50%Flax、胡麻-小麦-马铃薯-胡麻;WPFF:50%Flax、小麦-马铃薯-胡麻-胡麻;FFFF:100%Flax、胡麻-胡麻-胡麻-胡麻)对土壤团聚体、总有机碳(TOC)、土壤颗粒有机碳(POC)、土壤微生物碳(MBC)和氮(MBN)的影响。结果表明,休闲、不同轮作序列和低胡麻频率显著增加了030 cm土层<0.25 mm粒级的土壤团聚体含量、TOC和POC含量,而随胡麻频率的增加三者的含量呈下降趋势。其中,25%Flax处理下土壤团聚体含量较播前和休闲处理分别显著增加了2.02%4.04%和9.56%11.73%;土壤有机碳(SOC)较连作显著增加5.95%7.48%。50%Flax处理下胡麻位置对土壤SOC影响显著,且轮作(FWPF)显著高于连作(WPFF)。060 cm土层土壤SOC含量表现为休闲>播前≈25%Flax>50%Flax>100%Flax。与连作相比,轮作显著提高了010 cm土层土壤TOC和POC含量,呈现表层富集现象。土壤POC含量表现为25%Flax≈休闲>50%Flax>100%Flax。此外,轮作换茬显著增加了土壤MBC含量,且随着胡麻频率的增加,030 cm土层土壤MBC含量逐渐降低。与播前、休闲、轮作相比,连作显著降低土壤微生物碳氮比,50%Flax(WPFF)轮作序列和土层深度对土壤有机碳和微生物量的互作效应显著。综合来看,休闲可以显著改善土壤理化性状,25%胡麻频率的轮作序列利于保持土壤团聚体稳定性,增加土壤TOC、SOC和POC含量,而50%Flax轮作序列(WPFF)能够提高土壤微生物量和微生物碳氮比。表明25%胡麻频率的轮作序列均可维持土壤有机碳的稳定性,是旱地胡麻比较理想的轮作序列。     

Insect (black soldier fly larvae) oil as a potential substitute for fish or soy oil in the fish meal-based diet of juvenile rainbow trout (Oncorhynchus mykiss)

Alternative sources of fish oil (FO) are one of the major problems in aquaculture; therefore, the goal of the present study was to examine insect (black soldier fly larvae) oil (BSLO) as a potential replacer of fish/soy oil in juvenile rainbow trout (initial average weight of 32 ± 0.15 g) feed. Four diets were formulated wherein FO (control diet) was completely replaced with either soybean oil (SO) or BSLO, and an additional BSLO-based diet supplemented with 1.5% bile acid (BSLO + BA) were fed to the fish for 10 weeks. Growth performance of the BSLO fed group was similar (P > 0.05) to that of the FO and SO fed groups, however, the fish fed BSLO + BA diet registered the lowest growth (P < 0.05). Oil sources did not (P > 0.05) affect the major nutrient content of whole-body, however, the fatty acid composition of the muscle and liver was influenced (P < 0.05), with the highest 14:0, 16:0, and total saturated fatty acid detected in BSLO or BSLO + BA fed trout compared to the others (P < 0.001). No significant differences were observed in eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) or total n-3 polyunsaturated fatty acid (PUFA) content in muscle among the groups, whereas, the highest EPA:DHA and n-3:n-6 ratios were detected in the FO group. Gene expression for fatty acid binding protein (fabp), fatty acid synthase (fas), and Δ5 desaturase in the liver was lower in FO (P < 0.05), while BSLO + BA registered the highest Δ6 expression (P = 0.006). Supplementation of BA in the BSLO diet increased superoxide dismutase (SOD) and catalase (CAT) activities compared to the other groups (P < 0.05). In conclusion, BSLO could serve as a substitute for FO and SO in rainbow trout diet without negatively impacting growth performance, whole-body composition and nutrient retention, and modulate the expression of fatty acid metabolism-related genes in rainbow trout.     

Effect of dietary Schizochytrium microalga oil and fish oil on plasma cholesterol level in rats

The purpose of the study was to test the hypothesis that the dietary oils with different content of n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) affect plasma lipid level in rats in a different degree. The diets with 6% of fish oil (FO) and Schizochytrium microalga oil (SchO; EPA+DHA content in the diets 9.5 + 12.3 and 2.6 + 29.5% of the sum of total fatty acids, respectively) were used; the diet with 6% of safflower oil (high content of n‐6 PUFA linoleic acid, 65.5%; EPA+DHA content 0.7 + 0.9%) was used as a control. The difference between FO and SchO was established only in the case of plasma triacylglycerol (TAG) level: plasma TAG of the FO‐fed rats did not differ from the control rats (p > 0.05), while SchO decreased (p < 0.05) plasma TAG to 46% of the control. On the other hand, FO and SchO decreased (p < 0.05) total plasma cholesterol (TC) in rats in the same extent, to 73% of the control. Regarding the underlying mechanisms for the TC decrease, both SchO and FO up‐regulated hepatic Insig‐1 gene (181 and 133% of the control; p < 0.05), which tended (p = 0.15 and p = 0.19 respectively) to decrease the amount of hepatic nSREBP‐2 protein (61 and 66% of the control). However, neither SchO nor FO influenced hepatic 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase gene expression (p > 0.05); SchO (but not FO) increased (p < 0.05) low‐density lipoprotein receptor mRNA in the liver. It was concluded that the decrease of total plasma cholesterol might be caused by an increased cholesterol uptake from plasma into the cells (in the case of SchO), but also by other (in the present study not tested) mechanisms.