共查询到19条相似文献，搜索用时 312 毫秒
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茶皂素对菜青虫幼虫的拒食活性 总被引：1，自引：0，他引：1
测定了茶皂素对菜青虫幼虫的拒食作用。结果表明，当浓度高于８００ｍｇ·Ｌ－１时，茶皂素对菜青虫３、４、５龄幼虫均有很强的拒食活性；２４ｈ（小时）的拒食中质量浓度ＡＦＣ５０分别为１３０．３６、１７２．９７和２２０．８６ｍｇ·Ｌ－１。田间小区试验结果显示，６０％的茶皂素原粉１５０倍（４０００ｍｇ·Ｌ－１）和３００倍（２０００ｍｇ·Ｌ－１）液对芥蓝菜具有很好的保叶效果，对菜青虫的为害有一定的控制作用。 相似文献
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几种有机磷类杀虫药剂对美洲斑潜蝇活性的研究 总被引：9，自引：0，他引：9
测定了有机磷类农药毒死蜱、乐果、马拉硫磷、敌敌畏对美洲斑潜蝇各龄幼虫、雌成虫的毒力,进行了成虫取食及产卵的选择、非选择试验和田间小区试验。结果表明：美洲斑潜蝇１、２、３龄幼虫、雌成虫对毒死蜱最敏感,１、２、３龄幼虫对毒死蜱的ＬＣ５０分别是０．０６８２、０．１２１６、０．１４２３ｇ／Ｌ,雌成虫对毒死蜱２４ｈ、４８ｈ的ＬＣ５０分别是０．１５７１和０．１３０４ｇ／Ｌ;毒死蜱对美洲斑潜蝇的取食、产卵拒避持效期分别是６天和８天,用浓度０．４８ｇ／Ｌ毒死蜱处理２、４、６、８天后接虫,幼虫的存活率分别为０、１８．８％、４６．２％和７６．５％;田间用浓度０．４８、０．３２ｇ／Ｌ分别处理,６天的校正虫口减退率分别为９１．０７％和８６．３９％。 相似文献
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GL生根剂对扶桑插条生根及碳水化合物分配的影响 总被引：13，自引：0，他引：13
用ＧＬ生根剂（ＩＢＡ１０００ｍｇ／Ｌ＋粉锈宁１５０ｍｇ／Ｌ＋ＰＰ３３３２ｍｇ／Ｌ）５０ｍｇ／Ｌ浸泡扶桑插条基部２４小时，提高了插条的生根率、生根数、根干重，并扩大了生根范围。插条叶光合速率高于对照８２．８％，分配到叶的１４Ｃ－光合产物比对照少，而分配到茎和不定根的光合产物高于对照。插条叶和不定根中的可溶性糖、淀粉和纤维素含量低于对照，并随处理后天数的延长逐渐减少，木质素含量增加；茎和插条基部的可溶性糖含量高于对照，淀粉和木质素含量低于对照 相似文献
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虫螨光对几种蔬菜害虫的生物活性测定 总被引：2，自引：0，他引：2
虫螨光对蔬菜害虫小菜蛾,菜青虫,桃蚜,朱砂叶螨的生物活性ＬＤ５０（ＬＣ５０）分别为０．２０３７ｍｇ／ｋｇ、０．０１１１７μｇ／ｇ、０．０００２８５μｇ／头和０．００１４５ｍｇ／ｋｇ比常用对照农药三唑磷,氰戊菊酯,霸螨灵的生物活性分别强６３８．２９、４３．０４、５．３６８和８３７．４８倍。 相似文献
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以不同基因型材料的西瓜品种为试材，用ＭＳ、Ｍｉｌｌｅｒ、Ｎ６与不同激素配比的培养基，初步建立了西瓜离体组培再生体系。结果表明，不同浓度的ＭＳ培养基均可长出无菌苗，但随着ＭＳ培养基营养元素浓度的增大，无菌苗生长发育受到延迟和抑制作用加强，其中以 １／２ ＭＳ＋ ０．５～２ ｍｇ／Ｌ ＢＡ＋ ０． ｍｇ／Ｌ ＮＡＡ长出的无菌苗作外植体诱导愈伤组织最快，改良的 ＭＳ（ＭＳＩ＋ ２ ｍｇ／Ｌ ＢＡ＋０．１ｍｇ／ＬＮＡＡ）是西瓜愈伤组织诱导的最适培养基，改良的ＭＳ（ＭＳＩ＋２ｍｇ／ＬＢＡ＋０．１ｍｇ／ＬＮＡＡ＋５ ｍｇ／ＬＡｇＮＯ３）是外植体诱导分化不定芽的最适培养基，离子束等物理因子处理愈伤组织发现对诱导分化不定芽具有刺激和促进作用。 相似文献
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石竹花芽发生与内源多胺含量的关系 总被引：19，自引：0，他引：19
以石竹叶片为外植体，诱导愈伤组织、营养芽、花芽的培养基分别为ＭＳ＋ＺＴ２．５ｍｇ／Ｌ＋２，４－Ｄ０．３ｍｇ／Ｌ；ＭＳ＋ＺＴ１ｍｇ／Ｌ＋ＢＡ２ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ；ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．３ｍｇ／Ｌ。在石竹离体叶花芽形成过程中，内源多胺含量呈不同的变化趋势，腐胺、亚精胺含量上升，而二丙胺、精胺含量下降，表明多胺与石竹离体叶花芽分化有明显的内在联系。 相似文献
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AIMTo investigate the effect of Pulsatilla saponin A on proliferation and radiosensitivity of breast cancer cells and its mechanism. METHODSHuman breast cancer MCF-7 cells were treated with Pulsatilla saponin A at concentrations of 0, 5, 10, 15 and 20 mg/L and transfected with microRNA-24-3p (miR-24-3p) over-expression vector or inhibitory expression vector. The proliferation and radiosensitivity of the MCF-7 cells were measured by MTT assay and colony formation assay. The miR-24-3p expression and ring finger protein 2 （RNF2） mRNA level were detected by RT-qPCR. The protein expression of RNF2 was determined by Western blot. The luciferase reporter assay was used to detect the targeting relationship between miR-24-3p and RNF2. RESULTSCompared with control group (0 mg/L), the proliferation inhibitory rate of the MCF-7 cells was significantly increased in 5, 10, 15 and 20 mg/L Pulsatilla saponin A groups (P <0.05). The survival score of the MCF-7 cells treated with Pulsatilla saponin A was significantly decreased after irradiation, and the expression of RNF2 was significantly decreased (P <0.05). miR-24-3p targeted RNF2 and negatively regulated its expression. When the MCF-7 cells were simultaneously treated with Pulsatilla saponin A and miR-24-3p, the cell survival curve significantly shifted down. Inhibition of miR-24-3p expression reversed the proliferation-inhibiting and radiation-sensitizing effects of Pulsatilla saponin A on the MCF-7 cells. CONCLUSION Pulsatilla saponin A may affect the proliferation and radiosensitivity of breast cancer cells through miR-24-3p/RNF2 signaling pathway. 相似文献
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AIM:To study of the regulatory effect of lentinan on human leukemic HL-60 cell apoptosis and its effect on PI3K/AKT signaling pathway in HL-60 cells in vitro.METHODS:Lentinan at concentrations of 0 mg/L, 15 mg/L, 30 mg/L and 45 mg/L was applied to HL-60 cells cultured to the logarithmic phase in vitro, and the inhibitory effect of lentinan on the viability of HL-60 cells was measured by MTT assay after 24 h, 48 h and 72 h. The apoptosis induced by lentinan was analyzed by flow cytometry. The protein levels of cleaved PARP, cleaved caspase-9, cleaved caspase-3, cleaved caspase-8, cytochrome C, PI3K, AKT and p-AKT were determined by Western blot. After treatment with PI3K inhibitor LY294002 at 5 mg/L for 72 h, the apoptosis of HL-60 cells was analyzed by flow cytometry. RESULTS:The viability of HL-60 cells was inhibited after treatment with lentinan at concentrations of 15 mg/L, 30 mg/L and 45 mg/L for 24 h, 48 h and 72 h in concentration-dependent and time-dependent manners (P<0.05). The apoptosis of HL-60 cells was promoted after treatment with lentinan (15 mg/L, 30 mg/L and 45 mg/L) for 72 h in a concentration-dependent manner (P<0.05). The protein levels of cleaved PARP, cleaved caspase-9, cleaved caspase-3 and cytoplasmic cytochrome C in the HL-60 cells induced by 30 mg/L lentinan were increased significantly with the increase in the treatment time (P<0.05), but caspase-8 did not show any change. The protein levels of PI3K, AKT and p-AKT were decreased obviously with the increase in the lentinan concentration (P<0.05). Treatment of HL-60 cells with LY294002, a PI3K pathway inhibitor, produced apoptosis-inducing effect similar to lentinan (P<0.05). CONCLUSION:Lentinan induces HL-60 cell apoptosis by inhibiting PI3K/AKT signaling pathway. 相似文献
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HUANG Xiang-hua ZHANG Xiang-hong YAN Xia YIN Gui-ran LI Yue-hong TAN Yan-wei WANG Jun-ling WANG Feng-rong 《园艺学报》2002,18(2):169-171
AIM:To explore the putative effects of sterigmatocystin (ST) on human help T lymphocyte(Th1)function. METHODS:The effects of ST on interferon-γ(IFN-γ)secretion of human peripheral blood mononuclear cells(HPBMc) in vitro were determined with ELISA method. RESULTS:The effects of ST on IFN-γ secretion of HPBMc in vitro were closely dependent on ST concentrations. ST at relatively lower concentrations (0.03125-0.12500 mg/L) showed inhibiting effects on IFN-γ secretion. While, stimulating effects could be found when ST concentration was above 0.25mg/L. The highest level was seen in ST 1 mg/L group (P＜0.05)。At concentration ranging from 0.25 mg/L to 1 mg/L, a positive dose- effects correlation was found between ST concentration and IFN-γ secretion (r=0.492, P＜0.01). Time-effects analysis from 1 h to 64 h after ST treatment (1 mg/L)showed that the effects of ST on IFN-γ secretion varied as the changes of treatment times. An inhibiting effect on IFN-γ secretion of HPBMc 4 h and 8 h after ST treatment was found (8 h, P＜0.05). As the treatment time prolonged from 16 h, IFN-γ level gradually increased (32 h, P<0.05). There was a positive correlation between treatment time of ST and IFN-γ level of HPBMc in vitro from 16 h to 64 h after ST treatment (r=0.736, P＜0.01).CONCLUSION:The effects of ST on IFN-γ secretion of HPBMc in vitro closely depended on concentration and treatment time of ST. Generally, inhibiting effects were found at relatively lower ST concentration and shorter treatment period, while stimulation effects could be seen at relatively higher ST concentration and longer ST treatment time period. 相似文献
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ZHOU Zi-yi TANG Yu-ping JIN Hui-ming GAO Jun-peng ZHANG Guo-ping WANG Zhong Masao Mori CAI Ding-fang CAI Ye-feng 《园艺学报》2010,26(11):2229-2234
AIM: To investigate the neuroprotective effect of Ganoderma lucidum extract (GLE) in an in vitro model of primary cultured neurons with oxygen and glucose deprivation (OGD). METHODS: Neuronal injury was induced by oxygen and glucose deprivation/reoxygenation (OGD/R). The neuronal injury and viability were determined by LDH leakage and XTT assay at 0 h,3 h,6 h,12 h,24 h,48 h and 72 h after OGD/R. Neuronal apoptosis was detected by flow cytometry (FCM). The expression of apoptosis-related proteins was analyzed by Western blotting.RESULTS: The viability of the neurons increased with exposure to GLE (0.1 mg/L,1 mg/L and 10 mg/L)after OGD/R. The LDH releases were also significantly reduced. GLE significantly inhibited OGD/R-induced apoptosis of cultured rat cortical neurons in a concentration-dependent and time-dependent manner(P<0.05). GLE at concentrations of 0.1 mg/L,1 mg/L and 10 mg/L inhibited the expression of caspase-3 and caspase-8 proenzyme. Additionally,GLE at concentration of 10 mg/L suppressed the expression of caspase-9 proenzyme.CONCLUSION: Our findings provide the evidence that the GLE has neuroprotective effect on cerebral ischemia. The mechanisms are related to the inhibition of caspase-3,-8 and-9 activations. GLE may be a novel and effective reagent for treating ischemic stroke. 相似文献
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AIM: To investigate the effects of advanced glycation end products (AGEs) on protein and mRNA expression of macrophage inflammatory protein-1α (MIP-1α) in cultured human umbilical vein endothelial cells(HUVECs). METHODS: HUVECs were cultured with AGEs at different concentrations for 24 h and at a concentration of 400 mg/L for different time.The levels of mRNA and protein expression of MIP-1α in cultured HUVEC were detected by in situ hybridization and Western blot, respectively. RESULTS: In situ hybridization showed that after exposure of HUVECs to AGEs at different concentrations (100 mg/L, 200 mg/L, 400 mg/L) for 24 h, the average integrated optical density values (18.76±3.17, 26.58±1.61, 34.23±2.25) of MIP-1α mRNA expression in HUVECs were higher than that in control group (13.83±1.24, P0.05). After exposure of HUVECs to AGEs at a concentration of 400 mg/L for 12 h, 24 h and 36 h, the average integrated optical density values of MIP-1α mRNA expression in HUVECs were 22.67±1.46, 34.23±2.25 and 42.28±3.14, higher than that in 0 h group (12.56±1.24, P0.05). Western Blot showed that exposure of HUVECs to AGEs at different concentrations(100 mg/L, 200 mg/L, 400 mg/L) for 24 h resulted in a 1.34-fold, 1.87-fold and 2.46-fold increase in the expression of MIP-1α protein in HUVECs compared with BSA control group (P<0.05). Meanwhile, exposure of HUVECs to AGEs at a concentration of 400 mg/L for 12 h, 24 h and 36 h resulted in a 1.82-fold, 2.71-fold and 3.34-fold increase in MIP-1α protein expression in HUVECs compared with 0 h group (P<0.05). CONCLUSION:These data suggest that AGEs could induce a high expression of MIP-1αmRNA and protein in cultured HUVECs in a dose-dependent and time-dependent manner. 相似文献
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AIM: To investigate the effect of oxidized LDL (ox-LDL) on the expression of gap junction protein connexin43 in cultured human umbilical vein endothelial cells (HUVECs) in vitro. METHODS: Human umbilical vein endothelial cells cultured in normal condition were divided into blank control group, 50 mg/L,100 mg/L and 200 mg/L ox-LDL intervention groups. The mRNA expression of connexin43 in cultured HUVECs was detected with RT-PCR method; while the protein level of connexin43 was determined by the method of immunocytochemistry in the control and 100 mg/L ox-LDL intervention groups 24 h after ox-LDL was given. RESULTS: Different concentrations (50 mg/L, 100 mg/L, 200 mg/L) of ox-LDL up-regulated mRNA expression of connexin43 in cultured HUVECs after 24 h intervention (P<0.01). The protein level of connexin43 in cultured HUVECs intervened with 100 mg/L Ox-LDL for 24 h was up-regulated as compared to the control cells (P<0.01).CONCLUSION: Ox-LDL may up-regulate the expression of connexin43 at mRNA and protein levels in cultured human umbilical vein endothelial cells within short time, indicating that connexin43 plays an important role in the pro-atherosclerotic effect of Ox-LDL. 相似文献