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从药肥双减技术的内涵和特点、相关技术、存在问题和意见建议4个方面,探讨了药肥双减技术在苹果种植中的应用策略。结果表明,药肥双减技术能够有效提高苹果品质和产量,降低生产成本和风险,改善土壤肥力和水源质量,促进苹果产业绿色发展。基于此,建议加强药肥双减技术的研发和推广,提高农民的技术培训和服务,推广绿色生产模式和标准化管理,完善政策支持和市场保障,加强生态监测和风险管理。 相似文献
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《北方园艺》2020,(14)
以2个耐热性存在差异的菜心品种为试材,采用营养液栽培法,以28℃为对照(CK),研究35℃根际温度处理7 d后2种菜心的生长、根系结构、叶绿素荧光参数、光合参数及酶活性差异,以期研究水培菜心耐热性。结果表明:高温处理后‘诲南3号’和‘酒店60天’的茎粗、株高及地上部鲜质量分别较对照降低5.3%和8.4%,12.5%和4.5%,14.2%和22.4%。总根长、总表面积、根系分叉数及根总体积分别较对照降低25.2%和37.6%,25.5%和34.4%,30.1%和43.1%,22.9%和31.8%。Fo、Fm、ΔF/Fm′、qP和NPQ分别较对照降低4.7%和6.4%、2.9%和3.6%、15.7%和4.3%、11.8%和4.7%,7.3%和6.1%。Pn和WUE较对照分别降低6.9%和23.9%,13.1%和19.9%;Ci较对照分别增加2.6%和3.7%;‘诲南3号’Gs和Tr均较对照增加,而‘酒店60天’较对照降低。SOD、POD和CAT活性分别较对照降低1.4%和3.0%,38.8%和51.6%,11.2%和38.4%。高温对‘酒店60天’各指标影响大于‘诲南3号’,以地上部鲜质量、根总体积、Pn和CAT表现最为明显,可优先考虑作为水培菜心的耐热性指标。 相似文献
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研究琯溪蜜柚（Citrusgrandis‘Guanximiyou’）周年地上部新生器官生物量和氮（N）、磷（P）、钾（K）养分累积特性，为有针对性地科学施肥提供理论和实践依据。于2019和2020年在福建省平和县选取10年生盛果期琯溪蜜柚树为材料，测定其周年全生育期（5次）落花落果、叶片（挂果叶和未挂果叶）、枝条（挂果枝和未挂果枝）和果实（果皮和果肉）生物量，分析各器官N、P和K含量和累积动态。结果显示，地上部新生器官生物量随生育进程逐渐增加，收获期单株地上部新生器官生物量为16.70kg，其中果实、叶片、枝条和落花落果生物量分别占69.45%、23.59%、3.77%和3.19%，并以果肉（43.99%）和未挂果枝梢（22.55%叶和3.55%枝）为主。不同生育期叶片、枝条和果实中的N、P和K含量整体呈下降趋势，其中，挂果叶和枝条的N含量与挂果枝和果肉的P含量呈先下降后上升变化，而果肉的N含量与叶片和果肉的K含量则相反。琯溪蜜柚单株周年地上部新生器官N、P和K累积量分别为235.51、27.58和196.40 g，其中，收获果实带走N、P和K养分量分别为123.55、18.31和14... 相似文献
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张放 《柑桔与亚热带果树信息》2012,(3):34-39
苹果和梨分别是我国第一大和第三大出口水果。2011年我国苹果、梨出口延续了近3年的颓势，出口量继续下降，但出口额有所增加。2011年我国分别出口苹果、梨103．47万t和40．28万t，分别占我国干鲜水果出口总量的33．14％和12．90％，同比分别减少了7．86％和8．00％；出口额分别为9．14亿和2．86亿美元，分别占我国干鲜水果出口总额的28．68％和8．96％，同比分别增加了9．94％和17.39％。我国进口的苹果和梨数量相对较少，2011年我国进口的苹果和梨均有不同幅度增加，进口量分别为7．71万t和527t，同比分别增加了15．26％和39_28倍；进口额分别为1．16亿和104万美元，同比分剐增加了52．42％和13．88倍。我国苹果、梨主要是私营企业通过一般贸易方式出口，其中，私营企业出口的苹果和梨分别占苹果和梨出口总量的80．00％和85．09％，通过一般贸易方式出口的苹果和梨分别占苹果和梨出口总量的71．25％和78．34％ 相似文献
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本文结合了大量的文献和资料进行总结和分析,给予了一些建议和方法,希望能够保障工程的顺利进行和完成,能够保证施工质量的管理和控制得当。 相似文献
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测定金针菇菇脚和菌糠中的蛋白质和氨基酸含量,应用模糊识别法和氨基酸比值系数法,以鸡蛋蛋白质为标准蛋白,WHO/FAO氨基酸参考模式为评价标准,对金针菇菇脚和菌糠中蛋白质营养价值进行综合评价。结果表明:金针菇菇脚和菌糠蛋白质中总氨基酸含量分别为59.81%和55.29%,氨基酸种类齐全,必需氨基酸分别占总氨基酸量的40.27%和37.62%,相对于鸡蛋蛋白(标准蛋白)的贴近度为0.8257和0.7741。第一限制性氨基酸分别为苯丙氨酸+酪氨酸和赖氨酸,氨基酸比值系数为63.54和61.16。 相似文献
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AIM： To study the roles of ghrelin in the regulation of gastric distension (GD)-sensitive neurons in the hypothalamic arcuate nucleus (Arc) and gastric motility in diabetes mellitus (DM) rats. METHODS：DM rat model was made by intraperitoneal injection of streptozotocin. The effects of ghrelin and ［D-Lys3］-GHRP-6 on GD-sensitive neurons in the Arc of DM rats were observed by recording the extracellular potentials of single neurons, and the gastric motility was also monitored in vivo. The expression of ghrelin receptor,growth hormone secretagogue receptor (GHS-R), in Arc was studied by real-time PCR and immunofluorescene method. RESULTS：(1) Ninety-eight GD-sensitivity neurons were recorded in the Arc of normal rats, in which 64.3% were classified as GD-excitatory (GD-E) neurons and 35.7% were GD-inhibitory (GD-I) neurons. Microinjection of ghrelin excited 73.0% of the 63 GD-E neurons and the discharge frequency significantly increased as compared with the neurons treated with saline. Ghrelin inhibited 60.0% of the 35 GD-I neurons and the discharge frequency was significantly reduced (P<0.01). The effect of ghrelin was blocked by the antagonist of ghrelin ［D-Lys3］-GHRP-6. (2) Sixty-six GD-sensitive neurons were recorded in the Arc of diabetes rats, in which 64.3% were GD-E neurons, and 35.7% were GD-I neurons. Microinjection of ghrelin excited 35.1% of the GD-E neurons and the discharge frequency significantly increased as compared with the neurons treated with saline. Ghrelin inhibited 21 of the 29 GD-I neurons (72.4%) and the discharge frequency was significantly reduced. Compared with normal control group, the ratio of GD-E and GD-I neurons in diabetic rat Arc GD-sensitive neurons was not significantly changed. However, the ratio of GD-E neurons treated with ghrelin was significantly decreased, and the average increase rate of discharge frequency was significantly decreased. Ghrelin did not change GD-I neurons rejection ratio and discharge frequency average reduction rate. (3) Microinjection of ghrelin into the Arc significantly promoted gastric motility in normal and DM rats, and a significant dose-dependent manner was observed. However, the promotion effect of ghrelin on gastric motility in normal rats was stronger than that in DM rats, and the effect was completely blocked by ［D-Lys3］-GHRP-6. (4) The mRNA expression of GHS-R1a in the hypothalamic Arc of diabetic rats significantly reduced as compared with the normal control rats. The protein level of GHS-R1a in the hypothalamic Arc was also significantly reduced in DM rats. CONCLUSION：Ghrelin regulates the activity of GD-sensitive neurons in hippocampus Arc of diabetic rats by the action on ghrelin receptor. 相似文献
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AIM: To investigate the role of the nucleus tractus solitarius (NTS) in the regulation of paraventricular nucleus (PVN) AVP-ergic neurons on gastric ischemia- reperfusion injury (GI-RI). METHODS: Male SD rats were used in experiments. The celiac artery were clamped for 30 min and reperfused 1 h by removal of the clamp to obtain the ischemia-reperfusion state. The mechanism was analysed with nucleus electrical stimulation, electrolytic lesion and nucleus microinjection technique. RESULTS: Microinjection of arginine-vasopressin (AVP) into PVN obviously attenuated the GI-RI and dose-dependent effects were observed (r=-0.477, P<0.05) ; NTS lesion or microinjection of AVP antagonist into NTS both eliminated the attenuate effect of electrical stimulation of PVN on GI-RI. The effect of microinjection of AVP into NTS was similar to microinjection of AVP into PVN. CONCLUSION: The NTS participates in regulation of PVN AVP-ergic on GI-RI, which is mediated by the AVP receptor in the NTS. 相似文献
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WANG Qian LENG Hui LUAN Xiao GUO Fei-fei GAO Sheng-li SUN Xiang-rong XU Luo 《园艺学报》2019,35(7):1199-1205
AIM:To investigate whether glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) signaling pathway is involved in regulating the effects of exogenous γ-aminobutyric acid (GABA) in hypothalamic nucleus accumbens (NAc) on discharge activity of gastric distension (GD) sensitive neurons, gastric motility and gastric acid secretion in rats. METHODS:Fluorescence immunohistochemistry was used to observe the expression of GABA-A receptor (GABA-AR) and GLP-1R in rat NAc. The single-cell discharge recording experiment was used to observe the effects of GABA, GLP-1 and their receptor antagonists on the excitability of GD neurons in rat NAc. Implantation of cannula in rat NAc and injection of GLP-1, GLP-1R antagonist exendin 9-39 (Ex9) and GABA-AR antagonist bicuculline (BIC) were performed to investigate the changes of gastric motility and gastric acid secretion in the rats. RESULTS:GABA-AR and GLP-1R immunoreactive positive neurons coexisted in rat NAc. GABA inhibited the discharge activity of GD neurons in NAc, but this inhibitory effect was antagonized by BIC and partially blocked by Ex9. Microinjection of GABA into rat NAc promoted gastric motility and gastric acid secretion, which was antagonized by BIC and partially blocked by Ex9. CONCLUSION:Exogenous GABA in NAc may be involved in the regulation of gastric motility, gastric acid secretion and GD neuron excitability in the rats through GABA-AR signaling pathway. The promotion of GABA-AR signaling pathway is partially inhibited by GLP-1R signaling pathway. 相似文献
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GUO Yan-lin L&# Dou FENG Qi-long WANG Xiao-hui ZHANG Hua-ping YANG Cai-hong ZHENG Wen-liang KANG Yu-ming 《园艺学报》2018,34(6):982-988
AIM: To observe the effect of central prostaglandin E2 (PGE2) on sympathetic activation in chronic heart failure (CHF) and to explore the underlying mechanism. METHODS: Male SD rats were subjected to coronary artery ligation to induce heart failure (HF), and the intracerebroventricular infusion was performed by osmotic pump continuously. The rats in sham group and HF group were given artificial cerebrospinal fluid (0.25 μL/h). The rats in HF plus treatment group was given celecoxib (CLB; 20 mg/h). After 4 weeks, the levels of PGE2 in cerebrospinal fluid (CSF), the sympathetic nerve excitability and cardiac function were measured, and the changes of corticotropin-hormone releasing hormone (CRH)-containing neurons activation and neurotransmitter contents in the hypothalamic paraventricular nucleus (PVN) were also determined. RESULTS: Compared with the sham-operated rats, the HF rats had raised level of PGE2 in CSF, up-regulated renal sympathetic nerve activity and plasma norepinephrine, increased left ventricular end diastolic pressure, lung-to-body weight and right ventricular-to-body weight ratios, and decreased maximal increase and decreased rate of left ventricular pressure (P<0.05). In addition, the number of CRH positive neurons in PVN and the level of plasma adrenocorticotropic hormone were higher in HF rats than those in sham-operated rats (P<0.05). After administration of CLB into the lateral ventricle of HF rats, the contents of PGE2 in CSF were significantly reduced, the number of activation CRH neurons in PVN was decreased, the excitability of sympathetic nerves was down-regulated and cardiac function was improved (P<0.05). Compared with the sham-operated rats, the content of glutamic acid in PVN of HF rats was increased, the content of γ-aminobutyric acid and the number of glutamate decarboxylase 67-positive neurons were decreased (P<0.05). After the CLB was given, the above indexes were reversed (P<0.05). CONCLUSION: These findings indicate that in CHF, the increased central PGE2 may activate CRH-containing PVN neurons and contribute to the augmented sympathetic drive possibly by modulating the neurotransmitters within the PVN. 相似文献
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AIM:To investigate whether neuropeptide Y (NPY) receptor signaling pathway is involved in the regulation of orexin-A on food intake and glucose-sensitive (GS) neuronal excitability in the hypothalamic paraventricular nucleus (PVN) of diet-induced obese (DIO) rats. METHODS:Fluorescence immunohistochemistry experiment was used to observe the expression of orexin-A receptor (orexin receptor 1, OX1R) and NPY receptor Y5 (NPY-5R) in the PVN. The effect of orexin-A on the excitability of GS neurons in PVN was observed by single cell discharge recording. The cannula was implanted into the PVN of SD rats and DIO rats. The orexin-A, OX1R antagonist SB-334867 and NPY-5R antagonist CGP-71683 were injected through the cannula to observe the 0~2 h and 0~4 h food intake of the rats. RESULTS:The expression of OX1R and NPY-5R in the PVN of DIO rats was significantly higher than that in the SD rats. Orexin-A inhibited glucose-inhibited (GI) neurons and excited glucose-excited (GE) neurons in the PVN. However, the effects of orexin-A on GS neurons were partially blocked by the NPY-5R antagonist CGP-71683. Compared with the SD rats, orexin-A had more pronounced excitatory and inhibitory effects on PVN GS neurons in the DIO rats. Injection of orexin-A in the PVN increased food intake in the SD rats and DIO rats. However, the orexin-A-induced feeding was partially blocked by the NPY-5R antagonist CGP-71683. The effect of orexin-A on feeding was stronger in the DIO rats than that in the SD rats. CONCLUSION:The hypothalamic PVN orexin-A regulates food intake and GS neuronal excitability mainly through the OX1R signaling pathway, and NPY-5R signaling is also involved in this process, in which the regulatory effect on DIO rats is more sensitive. 相似文献
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AIM: To examine whether ischemic preconditioning (IPC) can protect against apoptosis in CA1 subfield of hippocampus following reperfusion of a lethal ischemia in rats and explore the role of IPC by inhibiting the expression of p53 in this process. METHODS: Wistar rats were used in the experiment. A global ischemia/reperfusion model was induced by 4-vessel occlusion. The rats were divided into the following three groups randomly: (1) ischemic preconditioning group (IPC group); (2) ischemia/reperfusion group (IR group); (3) control group. The histopathological changes, the percentage of apoptosis and the expression of p53 gene in CA1 region of rat hippocampus were examined by HE staining, FCM, RT-PCR and immunohistochemistry techniques. RESULTS: The neuronal density of CA1 region in IPC group ［(217±9)/0.72 mm2］ was significantly higher than that in IR group ［(29±5)/0.72 mm2, P<0.01］. The percentage of apoptotic neurons in IPC group (2.07%±0.21%) was lower than that in IR group (4.26%±0.08%), P<0.01. Compared with IR group, the expression of p53 gene in IPC group was significantly weakened. CONCLUSION: Ischemic preconditioning protects the ischemic neurons in CA1 region of rat hippocampus by inhibiting the expression of p53 gene. 相似文献
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AIM: In order to investigate the molecular mechanism of alcoholism acting on learning and memory, the dysfunction of learning and memory function was observed and the content of nitric oxide (NO) and neuronal nitric oxide synthase (nNOS) were determined in rats with acute alcoholism.METHODS: The mature male Sprague-Dawley rats were randomly divided into two groups. The experimental group animals were intraperitoneally administered with ethanol. The control group animals were injected with saline in the same way. The tests of learning and memory were performed at Y-maze after 6 h. Then brains were removed and the content of NO in brain tissue and nNOS expression in hippocampus CA1, corpus striatum were determined, respectively.RESULTS: (1) The training times to reach qualifying standards of Y-maze in experimental group (34.33±13.04) were higher than those in control group (27.50±8.79, P<0.05). (2) The content of NO in experimental group (23.09±9.60) in hippocampus CA1 was significantly increased (P<0.01) compared with that in control group (8.46±5.67). The content of NO in experimental group (19.46±8.25) in corpus striatum was also higher than that in control group (8.22±4.46, P<0.01). (3) The levels of nNOS expression in experimental group (34.33±13.04) in hippocampus CA1 increased significantly (P<0.05) compared with that in control group (27.50±8.79). nNOS positive neurons in experimental group (18.22±7.47) in corpus striatum were also higher than those in control group (10.15±4.24, P<0.05).CONCLUSION: These findings suggest that the mechanism of ethanol neurotoxicity may be partly involved in the signal pathway of NOS and NO in the brain. 相似文献
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DENG Yan-hong HUANG Mei-jin WANG Jian-ping LIN Tong-yu XIAO Jian CAI Yong-hua LIN Edward-H 《园艺学报》2009,25(11):2187-2191
AIM: To investigate the effect of 5-fluorouracil(5-FU)on the expression of the stem cell marker CD133 on colon cancer stem cells. METHODS: CD133 expression on several colon cancer cell lines was detected by flow cytometry. The CD133 positive cells from DLD1 cells were separated by the method of magnetic activated cell separation. Colony assay was used to measure self-renew ability and MTS assay was used to detect the sensitivity to 5-FU after separation. After 5-FU treatment, the change of CD133 mRNA level was measured by qPCR. RESULTS: CD133 expression on the surface of colon cacner cell lines DLD1, HT29, SW480, HCT116, Lovo, RKO was 30.20%, 82.00%, 0.34%, 91.80%, 85.30%, 0.28% respectively. DLD1 cells had two obvious populations according to CD133 expression. CD133 positive cells were separated from DLD1 cells, the positive purity was 87.21%±5.33% and the negative purity was 84.30%±4.65%. CD133 positive cells formed more colonies with limited dilution colony assay(46.33%±4.44% vs 31.00%±2.00%, P<0.05). CD133 positive cells were less sensitive to 5-FU compared to CD133 negative cells(20% less, P<0.01). 5-FU at concentration of 1 mg/L upregulated CD133 mRNA expression in both DLD1 and HT29 cells, the relative quantity was increased from 1 to 1.684±0.012(P<0.01)and 30.702±0.280 to 49.379±0.460(P<0.01)in HT29 and DLD1, respectively. CONCLUSION: Compared to CD133 negative cells, CD133 positive cells show more ability to form colonies in vitro, and are less sensitive to 5-FU. 5-FU upregulats the mRNA expression of CD133, resulting in the CD133 colon cancer stem cells enrichment during 5-FU treatment. 相似文献
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AIM:To observe the expression of corticotropin releasing hormone (CRH) within the paraventricular nucleus of hypothalamus (PVN) and to explore the relationship between the activated CRH-containing neurons and sympathetic activity in rats with heart failure (HF).METHODS:Healthy male Sprague-Dawley (SD) rats were subjected to coronary artery ligation to induce HF,and chronic intracerebroventricular (ICV) infusion was performed by osmotic pump for 4 weeks.The rats in sham group and HF group were given vehicle (VEH;artificial cerebrospinal fluid 0.25 μL/h).The rats in HF plus treatment group were treated with CRH competitive inhibitor αh-CRH (15 mg/h).Meanwhile,the Lewis rats and Fischer 344 rats for control study also underwent coronary ligation to induce HF or sham surgery.After 4 weeks,left ventricular end-diastolic pressure (LVEDP) and maximum positive/negative change in pressure over time (±dp/dtmax) were determined.The right ventricular-to-body weight (RV/BW) and lung-to-body weight (lung/BW) ratios were calculated.The renal sympathetic nerve activity (RSNA) was recorded and the plasma norepinephrine (NE) level was measured.The expression of CRH in the PVN combined with the plasma adrenocorticotrophic hormone (ACTH) levels were measured.RESULTS:Compared with the sham-SD rats,the HF-SD rats had a greater number of CRH positive neurons in the PVN (accordingly the plasma ACTH levels were increased),accompanied by decreased±dp/dtmax and increased RSNA,plasma NE,LVEDP,lung/BW and RV/BW.However,ICV treatment with αh-CRH attenuated these changes in the HF-SD rats (P<0.05).Compared with the sham-Fisher 344 rats,the HF-Fisher 344 rats also had a greater number of CRH positive neurons in the PVN (accordingly the plasma ACTH levels were increased).In addition,they had significantly increased RSNA and plasma NE level,higher LVEDP,RV/BW and lung/BW,and lower±dp/dtmax(P<0.05).Compared with the SHAM-Lewis rats,the HF-Lewis rats had not significantly changed in the above parameters.CONCLUSION:In CHF,the CRH-containing neurons in PVN are activated,thus aggravating cardiac function by increasing sympathoexcitation. 相似文献