外源褪黑素对高温胁迫下葡萄幼苗生理特性的影响

以‘黑比诺’葡萄幼苗为试验材料,利用人工气候箱模拟高温环境,研究高温胁迫下外源褪黑素预处理对葡萄幼苗叶片中丙二醛MDA含量、渗透调节物质(脯氨酸、可溶性糖和可溶性蛋白)含量以及抗氧化酶(SOD、POD和CAT)活性的影响,以期探明褪黑素与葡萄耐热性之间的关系,为葡萄生产上进一步应用褪黑素提供理论指导。结果表明,高温处理下,葡萄幼苗叶片中MDA含量显著增加,脯氨酸、可溶性糖和可溶性蛋白含量等渗透调节物质提高,SOD、POD和CAT活性也显著增强;同时,外源褪黑素预处理能显著降低高温胁迫下葡萄幼苗叶片中MDA含量,增强葡萄幼苗叶片中SOD、POD和CAT活性,提高脯氨酸、可溶性糖和可溶性蛋白含量。由以上可知,外源褪黑素可通过提高抗氧化酶的活性及渗透调节物质的含量,降低膜质过氧化水平,保护脂膜的完整性,从而增强葡萄幼苗抵抗高温胁迫的能力。     

大粒晚熟耐贮葡萄新品种──夕阳红

大粒晚熟耐贮葡萄新品种──夕阳红辽宁省农业科学院园艺研究所徐桂珍等研究选育出的大粒、晚熟、耐贮葡萄新品种“夕阳红”，系以玫瑰香芽变为母本、巨峰为父本进行杂交育成。该品种属欧美杂种、四倍体。果实于９月下旬成熟。果稳大，长圆锥形，平均穗重１０６６ｇ，平均...     

海口林场不同品种葡萄物候期与结果习性的调查与分析

采用田间调查与统计分析的方法,对20多年生水晶、赤霞珠、玫瑰香3种葡萄的物候期、主要生长结果习性及果实性状进行分析。结果表明,酿酒型葡萄玫瑰香和赤霞珠从萌芽到成熟时间相隔2 d,水晶葡萄相对这2个品种较晚;在萌芽率、成枝率、结果枝率方面,玫瑰香表现较好,在结果系数方面赤霞珠表现较好,果实性状差异不显著,均表现较好。水晶葡萄结果系数较低,果实性状的各项指标相对较低。综合表现玫瑰香葡萄各项指标均较高,适宜今后长期栽培。     

“北京吐鲁番”，打造京南葡萄之乡

正绿思维生态园、喜山葡萄采摘园、葡萄大世界……初秋的采育瓜果满园,葡萄飘香,采育葡萄种植历史已有上百年。种植的葡萄品质优良、含糖量高、口感好,汇集巨玫瑰、巨峰、夏黑、玫瑰香、金手指、阳光玫瑰等50多个品种。每年的8月至10月,"京南吐鲁番"大兴区采育镇的上万亩葡萄进入成熟期,采育已成为首都市民周末争相"打卡"的休闲佳地。     

外源Ca~(2+)对高温下多叶羽扇豆生理指标的影响

以多叶羽扇豆为试验材料,通过喷施外源Ca2+,研究外源Ca2+对高温胁迫下多叶羽扇豆的生理指标的影响,探讨多叶羽扇豆的耐热性。结果表明:高温胁迫下,多叶羽扇豆细胞内的电解质外渗,膜透性增大,细胞膜受到损伤,叶绿素含量降低,MDA含量增高,SOD活性、POD活性升高。喷施CaCl2可降低电解质外渗,降低细胞膜的伤害率。外源Ca2+对降低MDA含量有一定的作用,可帮助多叶羽扇豆抵抗高温环境。喷施外源Ca2+能够提高SOD、POD酶活性,不能提高多叶羽扇豆叶片内叶绿素含量。     

无核化处理对‘玫瑰香’葡萄果实香气的影响

为了了解无核化试剂对葡萄果实香气的影响,以10年生的‘玫瑰香’葡萄为试材,在花期进行无核化处理,成熟期测定果实香气物质。结果表明,在无核化处理的果实香气中增加了里那醇、2-己烯醛的含量,还检测出(S)-(±)-柠檬烯、β-月桂烯、蒎烯、紫苏烯、苯乙醇、异戊醇等萜烯类物质。综合来看,无核化处理丰富了‘玫瑰香’葡萄的香气物质。     

水杨酸对铬胁迫下紫花苜蓿幼苗生理特性的影响

以"甘农3号"紫花苜蓿(Medicago sativa L.)为材料,采用盆栽试验,研究外源SA对Cr6+胁迫下紫花苜蓿幼苗叶片中抗氧化酶SOD、POD及CAT的活性和渗透调节物质脯氨酸、丙二醛及叶绿素含量等逆境生理指标的影响。结果表明:1.5mmol/L和1.0mmol/L的Cr~(6+)组合处理能显著提高幼苗中叶绿素的含量和SOD、POD及CAT的活性,而降低丙二醛和脯氨酸的含量。暗示一定浓度的外源SA可能通过激活抗氧化酶SOD、POD及CAT的活性,加快活性氧物质的清除速度,缓解重金属胁迫对幼苗叶片造成的氧化损伤,进而提高紫花苜蓿的抗逆性。     

葡萄施用稀土方法

葡萄施用稀土可提高葡萄产量(27-35％)、果实含糖量，每亩可增加收入83元。方法：(1)喷施浓度为0．05～0．40%，即1kg农用稀土“常乐”加水1000kg或2000kg。喷洒时以雾滴布满叶片不下滴为宜；     

环剥对玫瑰香葡萄枝条生长和果实品质的影响

研究了环剥处理对玫瑰香葡萄枝条生长及果实品质的影响。结果表明：环剥处理具有抑制主梢生长和副梢生长,促进新梢成熟和果实生长发育的作用。同时果粒平均纵横径、果粒平均重量、可溶性固形物含量均显著增加。     

葡萄新秀──京优

葡萄新秀──京优京优葡萄系中国科学院北京植物园从黑奥林自然杂交实生苗中选育而成。属欧美杂交种，为京亚的姊妹系，亦为四倍体品种。该品种为目前巨峰群大粒品种中，果肉脆、品质好、耐运输、较早熟品种。①植物学特性。嫩梢叶片正面无绒毛，紫红色或红褐色，成龄叶片...     

Antimicrobial activity of some Indian mosses

The present study was designed to evaluate the antimicrobial activity of ethanolic extracts of 15 Indian mosses. The antibacterial activity of ethanolic extracts was investigated against five G(+) and six G(-) bacterial strains. Antimycotic activity was assayed against 8 fungi. Sphagnum junghuhnianum, Barbula javanica, Barbula arcuata, Brachythecium populeum, Brachythecium rutabulum, Mnium marginatum and Entodon cf rubicundus were found to be most active against all the organisms.     

勐腊自然保护区亚洲象活动的时空规律及保护建议

采取野外监测和跟踪调查、资料查阅、村寨访谈、数据分析等方法,分析亚洲象在勐腊保护区的活动区域变化,季节、日的活动规律。结果发现,与2010年相比,亚洲象的活动范围已扩大到勐腊保护区60%的区域以及保护区以外的东北部区域,这些区域主要在人类活动频繁的村落周围;在活动时间上,一年中活动最频繁的时间为4—8月,一天中活动最频繁的时间为下午到夜晚(17—21点),表明亚洲象的活动区域、活动范围与食源密切相关。对亚洲象保护的管理规范、群众保护意识有所增强等有利因素和食源减少、食性改变、栖息地减少等不利因素进行分析;提出引导当地居民调整种植结构、合理安排生产活动时间,开展跨境保护、加强栖息地保护,加强宣传、建立预警预报系统等缓解人象冲突的对策。     

脱氢枞胺-壳聚糖阳离子表面活性剂的合成及性能研究

以壳聚糖(相对分子质量为1 000、1 500、3 000)和脱氢枞胺为原料,合成了一类新型壳聚糖衍生物——脱氢枞胺-壳聚糖阳离子表面活性剂(a、b、c),通过FT-IR、1H NMR对产物结构进行了分析和表征,并对产物的表面活性、乳化性能及抑菌性能进行了研究。研究结果表明,25℃下产物a、b、c的临界胶束浓度(CMC)为3.98×10-4,2.51×10-3,5.01×10-3mol/L,CMC对应的表面张力(γcmc)分别为38.6,36.8,36.6 mN/m;乳化时间分别为44、71、148 s;采用最低抑菌浓度法对目标产物的抑菌性能进行了测试,初步的结果显示化合物都有一定的抑菌活性,特别是化合物a、b、c对产气肠杆菌的抑菌效果优于市售杀菌剂新洁尔灭和氨苄青霉素钠,对其最低抑菌浓度分别为2、2和4 mg/L。产物的抑菌性能随取代度的增大而增强,随壳聚糖分子质量的增大而有所降低。     

Preliminary antinociceptive, antioxidant and cytotoxic activities of Leucas aspera root

The ethanolic extract of Leucas aspera root was subjected to acetic acid induced writhing inhibition, 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging assay and brine shrimp lethality bioassay for screening of antinociceptive, antioxidant and cytotoxic activity, respectively. The extract produced significant writhing inhibition in acetic acid induced writhing in mice at the doses of 250 and 500 mg/kg. The extract showed a significant free radical scavenging activity with an IC(50) of 8 microg/ml. The extract showed significant lethality to brine shrimp with an LC(50) value.     

姜黄素衍生物的合成和生物活性研究（英文）

以姜黄素和马来酸酐为原料,经酯化、异构化、酰氯化和酯化合成了4个姜黄素衍生物。姜黄素衍生物c1~c4的收率分别为80.5%、83.7%、81.2%和85.4%,用IR,1H NMR和13C NMR确证了目标化合物的结构。并对c1~c4的抗氧化活性和抗菌活性进行了评价。结果表明,姜黄素衍生物c1~c4清除DPPH·的IC50分别为164.14±0.82、166.98±0.66、171.97±0.99和175.10±2.34 mg/L,它们的抗氧化活性均低于姜黄素(36.22±0.22 mg/L),姜黄素的酚羟基对抗氧化活性有重要影响。c1~c4均具有良好的抗菌活性,其中化合物c4的抗菌活性最好,c4对金黄色葡萄球菌、大肠杆菌、青霉菌和黑曲霉菌的最小抑菌浓度(MIC)分别为0.5、0.5、0.25和1.0 g/L。α,β-不饱和羰基结构的化合物修饰姜黄素有望开发新的抗菌药物。     

Analgesic, anti-inflammatory and antipyretic activities of the ethanolic extract and its fractions of Cleome rutidosperma

Oral administration of the ethanolic extract (200 and 400 mg/kg, p.o) and its fractions (200 mg/kg each) of the aerial parts of Cleome rutidosperma produced significant analgesic activity in acetic acid-induced writhing and tail immersion tests, anti-inflammatory effect against carrageenin induced inflammation and adjuvant induced polyarthritis and antipyretic activity against yeast-induced pyrexia. Fractionation of the ethanolic extract potentiated the activities.     

异长叶烯基噻唑类化合物的合成及其抑菌、抗肿瘤活性研究

以异长烯酮为原料,通过缩合、亲核取代和环化等手段合成了11种新型异长叶烯基噻唑类化合物,同时采用1H NMR、13C NMR、LC-MS和FT-IR对化合物进行了鉴定,从而确定了化合物的结构。对目标化合物进行了抑菌活性实验,结果表明:(E)-4-(4-甲氧基苯基)-2-(2-(1,1,5,5-四甲基-3,4,5,6-四氢-1H-2,4a-亚甲基-7(2H)-亚基)肼基)噻唑(2e)与(E)-4-(4-甲基苯基)-2-(2-(1,1,5,5-四甲基-3,4,5,6-四氢-1H-2,4a-亚甲基-7(2H)-亚基)肼基)噻唑(2g)对细菌(大肠杆菌与金黄色葡萄球菌)具有较好的抑制效果,最低抑菌质量浓度(MIC)为7.8 mg/L。(E)-4-氯苯基-2-(2-(1,1,5,5-四甲基-3,4,5,6-四氢-1H-2,4a-亚甲基-7(2H)-亚基)肼基)噻唑(2b)对真菌(白念球菌与热带假丝酵母)抑制效果优于其他化合物,其MIC值为15.6 mg/L。采用噻唑蓝(MTT)法对目标化合物进行了人体肝癌细胞(HepG 2)抗癌活性测试,化合物2g(IC50=43.9±0.9 mg/L)对HepG 2具有较好的抗癌活性。     

Evaluation of biological activities of extracts from 22 African tropical wood species

Heartwoods of 22 African tropical wood species were extracted with methanol and the contents of total phenolic compounds in these extracts were measured. Three bioassays were conducted to evaluate the antioxidant activity, tyrosinase inhibitory activity, and antifungal activity of the methanol extracts. The results indicated that the extracts from 13 species exhibited high antioxidant potential, and their inhibitory concentrations that caused 50% scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (IC₅₀) were less than 10 μg/ml. The crude extract from Cylicodiscus gabunensis showed the highest antioxidant activity, and was even higher than that of (+)-catechin, which is known as a potent antioxidant. There was a good correlation between the antioxidant activity and the content of total phenolic compounds, indicating that phenolic compounds played a predominant role in the antioxidant property of the wood extracts. Among all 22 species, only 1 species, Milicia excelsa, contained extractives that showed very high tyrosinase inhibitory activity. The extracts from 9 species showed high antifungal activity. No consistent relationship was observed between the tyrosinase inhibitory activity or antifungal activity and the content of total phenolics in the extracts. Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, August 2006     

Antioxidant activity of Erica arborea

The antioxidant properties of the methanol extract of leaves and flowers of Erica arborea and the ethyl acetate, butanol and water soluble fractions were investigated. The ethyl acetate extract was found to be the richest for phenolic and flavonoid content which showed the highest antioxidant activity.     

Antiparasitic antioxidant phenylpropanoids and iridoid glycosides from Tecoma mollis

A radical scavenging guided phytochemical study on the stem bark of Tecoma mollis afforded seven active phenylpropanoid glycosides (1–7), including a new one (4), and one iridoid (8). The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (1–7) displayed promising antioxidant activity (DPPH assay) in relation to ascorbic acid (positive control). The antimicrobial activity for compounds (1–8) was evaluated against five bacterial and five fungal strains. The isolated compounds exhibited nonselective weak to moderate antimicrobial activity. The highest antileishmanial activity against Leishmania donovani was observed for compound (7) with an IC₅₀ value of 6.71 μg/ml, using pentamidine and amphotericin B as drug controls. Compound (5) exhibited moderate antimalarial activity (45% inhibition) against chloroquine sensitive (D6) clones of Plasmodium falciparum.