农户休耕意愿与不同模式的补偿标准——以太行山北麓平原、黑龙港地区为例

农户是耕地利用主体,研究其视角下的休耕意愿和不同模式的受偿标准,对政策推行有实际意义。以太行山北麓平原、黑龙港地区为例,调研走访农户分别得到81份和148份有效问卷,通过统计分析、机会成本法和受偿意愿法等,研究了农户休耕意愿和不同模式的补偿标准。结果表明:（1）超过50%受访农户休耕意愿依补偿而定,两区域调整种植结构模式的接受度均高于减少灌溉次数模式。考虑到粮食安全,黑龙港地区调整为种植春玉米,水资源补给性较好的太行山北麓平原实行减少灌溉次数方式;（2）不同模式下两区域农户受偿意愿值均高于机会成本值。建议种植春玉米时补偿标准为7 500元/hm²,减灌时太行山北麓平原、黑龙港地区补偿标准分别为灌溉1次下2 504.7元/hm²,2 126.4元/hm²,灌溉2次下1 252.35元/hm²,1 063.2元/hm²。本研究从农户视角对休耕政策进行了反馈,提出不同模式下的补偿标准,为休耕政策的具体制定和实施提供借鉴。     

太行山南麓5个林龄侧柏人工林土壤酶活性季节变化

采用时空互代法,以太行山南麓地区20,30,40,50,60年生侧柏人工林土壤为研究对象,研究了土壤蔗糖酶和脲酶活性的季节变化、空间分布特征及其与土壤因子的相关性。结果表明:土壤酶活性有明显的季节变化特征,土壤蔗糖酶的活性呈夏季 > 秋季 > 春季 > 冬季,脲酶活性的季节动态呈夏季 > 春季 > 秋季 > 冬季,两种土壤酶活性均在夏季最高,冬季最低。土壤蔗糖酶和脲酶活性均随土层深度的增加而显著降低（p<0.01）,从表层0-10 cm至深层30-40 cm酶活性下降幅度均超过46%。相关性分析表明,土壤蔗糖酶和脲酶均与土壤含水率、DOC含量呈极显著正相关关系,且两者之间也存在极显著正相关关系（p<0.01）,但是二者的主要影响因子并不完全一致。逐步回归分析表明蔗糖酶活性的主要影响因子是土壤含水率和砂粒体积分数,二者能解释71.2%的变化;脲酶活性的主要影响因子是DON、土壤含水率、硝态氮含量和土壤容重,四者能解释71.5%的变化,暗示温度和水分可能是该区人工林土壤生物活性的主要控制性因素。     

氮磷钾养分配比对温室土培黄瓜产量及品质的影响

在日光温室内,采用盆栽方式研究了不同氮磷钾养分配比对土壤栽培黄瓜产量及其品质的影响。结果表明：增加磷素用量和比例可以显著提高黄瓜的产量;适量氮钾肥配合增施磷肥可以增加果实中可溶性蛋白含量,适量氮磷肥配合增施钾肥可以改善果实品质,提高可溶性糖和维生素C含量,降低硝酸盐含量。     

苹果属小金海棠MxIrt1基因特异性片段的原核表达及多克隆抗体的制备

 MxIrt1是从苹果属植物小金海棠中克隆出的二价阳离子转运膜蛋白基因。为进一步研究该基 因的功能, 利用MxIrt1基因位于第3和第4跨膜区之间的162 bp片段, 构建了原核表达载体pGEX-MxIrt1,经原核表达、亲和层析、获得GST2MxIRT1融合蛋白, 以融合蛋白为抗原, 制备多克隆抗体, ELISA方法检测抗体效价阳性, 蛋白质印迹检测植物体内总蛋白, 获得与预期大小一致的特异性条带。上述结果表明,表达的目的蛋白可用于免疫组织化学、蛋白质印迹检测。     

茎芥菜胞质四倍体白菜雄性不育系花药发育的研究

 以茎芥菜胞质雄性不育系与四倍体白菜杂交获得的同源四倍体白菜异源胞质雄性不育系及其保持系为材料,采用形态学和石蜡切片方法研究其花药解剖结构及发育。结果表明：该雄性不育为结构性雄性不育,其退化或畸形雄蕊分为5种类型：盾状雄蕊、条状雄蕊、片状雄蕊、羽状雄蕊和瓣状雄蕊。该雄性不育系花药发育败育有两个时期,盾状雄蕊花药败育于孢原细胞分化期,雄蕊整个发育时期均处在孢原细胞分化期,无绒毡层与花粉母细胞的分化,不形成药室,属孢子体败育型;其它类型雄蕊,花药败育发生在雄蕊原基分化时期,由于雄蕊原基偏离正常的分化轨道,形成瓣状化雄蕊。     

Effect of Beclin 1 RNA interference on Vit K3 injured SMMC-7721 cells

AIM: To observe the effect of Beclin 1 silencing by RNA interference (RNAi) technique to the injury of SMMC-7721 hepatoma cells by vitamin K3 (Vit K3).METHODS: The recombinant plasmid Psilencer 3.1-siRNA-Beclin 1 was transfected into SMMC-7721 hepatoma cells by eukaryotic cell transfection technique. Plasmid vector and cell culture medium were used as negative and control, respectively. The cells were collected 48 h later to extract cell RNA and total protein and to detect Beclin 1 gene expression by RT-PCR and Western blotting. 40 μmol/L Vit K3 was used to treate the Beclin 1-siRNA cells, Hoechst33342 staining was used for the determination of the percentage of cell apoptosis.RESULTS: Compared with the control group, the synthetic siRNA of Beclin 1 significantly decreased the levels of Beclin 1 mRNA and protein expressions. Beclin 1 mRNA was up-regulated in 40 μmol/L Vit K3 treated SMMC-7721 hepatoma cells, the percentage of apoptosis cells increased (P﹤0.01). In beclin 1-siRNA cells, Beclin 1 mRNA was down-regulated obviously, the percentage of apoptosis cells increased significantly compared with the 40 μmol/L Vit K3 group (P﹤0.01).CONCLUSION: The transfection of SMMC-7721 hepatoma cells by Psilencer3.1-siRNA-Beclin 1 effectively inhibits the expressions of Beclin 1 mRNA and protein, inhibits the activation of Beclin 1 dependent autophagic signaling pathway, and aggravates the apoptosis induced by Vit K3.     

Effect of transketolase-like protein 1 on proliferation of human nasopharyngeal carcinoma cells

AIM: To investigate the effect of transketolase-like protein 1 (TKTL1) on proliferation of human nasopharyngeal carcinoma cells in vitro. METHODS: The siRNA against TKTL1 mRNA was constructed and transfected into human nasopharyngeal carcinoma cells (CNE cell line). The activity of transketolase was detected before and after RNA interference.Real-time PCR was used to determine the mRNA expression of transketolase (TKT) gene family in the CNE cells.Flow cytometry and MTT test were used to detect the effect of anti-TKTL1 siRNA on cell proliferation and cell cycle in the CNE cells. RESULTS: The total transketolase activity was significantly decreased in the CNE cells transfected with siRNA TKTL1 construct compared with the cells transfected with control vector or untransfected CNE cells. No significant difference in the expression level of TKT and TKTL2 gene between the CNE cells transfected with siRNA TKTL1 construct and the cells transfected with control vector or untransfected CNE cells was observed (P>0.05). However, the expression level of TKTL1 gene was significantly downregulated in the CNE cells transfected with siRNA TKTL1 construct compared with the cells transfected with control vector.Cancer cells were arrested in G0/G1 phase, and cancer cell proliferation was significantly inhibited in the CNE cells transfected with siRNA TKTL1 construct. CONCLUSION: TKTL1 plays an important role in the total transketolase activity and cell proliferation of human nasopharyngeal carcinoma. TKTL1 may be considered as a potential target for novel anti-cancer therapy.     

Protective effect of bivalent anti-snake venom IgY administered intragastrically on mice with cobra or viper envenomation

AIM: The different effect of bivalent immunoglobulin Yolk (IgY) was evaluated against snake venom between intragastric administration and intraperitoneal injection in mice with cobra or viper envenomation. METHODS: The venom of naja and viper was injected alternately into the leghorn hen. Bivalent anti-snake venom IgY was extracted by water dilution. The concentration of bivalent IgY in plasma was observed in indirect ELISA assay after bivalent anti-snake venom IgY taken orally. The gastric emptying function test was used for determining optimization time after gastric administration of IgY. The protective effect of bivalent anti-snake venom IgY was compared between intragastric administration and intraperitoneal injection in mice with cobra or viper envenomation. RESULTS: Bivalent anti-snake venom IgY was extracted from eggs laid in 28-42 d after the first immunization. The titers of Bivalent IgY against cobra and viper venom were 1∶12 800 and 1∶6 400. At the time of 2.5-3.5 h after bivalent anti-snake venom IgY was taken orally in three concentrations (75 mg, 150 mg, 300 mg·0.5 mL-1·20 g-1 BW), the gastric evacuation rate of mice was above 68.9%, with the plasma concentration of bivalent IgY in peak. The survival time of mice envenomation with snake venom was extremely prolonged (P<0.01), after IgY was taken by intragastric administration or intraperitoneal injection. While administration with the same dose of IgY, the survival rate of mice envenomation with cobra venom was higher than that of viper venom. The effective dose of intragastric administration was decuple higher than that of intraperitoneal injection. CONCLUSION: The animal envenomation with cobra or viper venoms can be significantly protected by bivalent anti-snake venom IgY with intragastric administration or intraperitoneal injection.     

沼气发酵过程混合搅拌研究进展

在沼气工程中设置混合搅拌装置,可以提高反应的传质效率,加快产沼气过程的进行,而混合搅拌装置的电耗占整个沼气工程电耗的很大部分,这成为混合搅拌装置深入推广的主要限制因素.本文对国内外沼气发酵混合搅拌过程中搅拌方式和搅拌模式的研究现状进行综述.     

培育发展长春市农机工业和流通业的思考

通过对培育发展长春市农机工业和流通业的宏观背景与条件的综合分析,提出了加快发展农机工业及流通业的指导思想和主要任务,阐述了培育发展农机工业和流通业应采取的有效措施.