Correlation between hydrolytic enzyme activities measured in bean seedlings afterTrichoderma koningii treatment combined with pregermination and the protective effect againstPythium splendens

An experimental protocol consisting in the colonisation of pregerminated bean seeds dressed withTrichoderma sp. was used in order to study the mechanisms correlated with the protective effect againstPythium splendens. Seed dressed with TH-11 (T. koningii) for 24 h presented a higher protective effect and a higher level of seed colonisation as compared to those dressed with TH-13 (T. longibranchiatum). The levels of seed coat colonisation by TH-11 and TH-13 was shown to be correlated with the carboxymethylcellulase activity, as measured in the seed coats retreived from germinating dressed bean seeds. The seed coat colonisation was also associated with an increased activities of endo-1,3--glucanase and endochitinase measured in seed extracts, and an inhibitory effect of seed extracts onPythium sporangia germination. Pretreatment of TH-13-dressed seeds with a commercial cellulase improved all parameters mentioned above, thus suggesting a role of cellulase activity in the colonisation process and the linked protective effect. The possible role of hydrolytic enzymes in the protective effects is discussed.     

真空渗入法转pinⅡ基因菜薹外源基因的遗传与表达

 本研究对利用真空渗入法获得的转bar基因及pinⅡ基因菜薹，进行了外源基因的遗传及表达情况分析。结果表明通过该方法获得的转基因植株，外源基因能够稳定遗传。bar基因在 代的分离大部分符合孟德尔遗传规律，但也有不符合的群体；pin II基因在 代中稳定表达，但各个株系之间的表达水平差异较大，因而各个株系的抗虫效果也具有显著差异，即使具有相同外源基因拷贝数的各个株系，其PIN I／蛋白表达量和抗虫效果也具有显著差异。     

优化施肥下长江流域冬小麦产量及肥料增产效应

【目的】针对长江流域冬小麦不合理施肥带来的肥料利用率低的现状,探讨冬小麦产量分布特征及施用氮、磷和钾肥料的增产效应,为长江流域冬小麦肥料减施增效和优化养分管理措施提供依据。【方法】本文数据来源于国际植物营养研究所(IPNI)于2000—2018年在我国长江流域开展的田间试验,以及在中国知网(CNKI)数据库通过检索字段或字段组合(冬小麦、冬小麦+产量及冬小麦产量+肥料利用率等)得到的此期间关于长江流域冬小麦田间试验的论文,共1 732个田间试验。试验处理包括:优化施肥处理,农民习惯施肥,以及在优化施肥和农民习惯施肥基础上的不施氮肥、不施磷肥和不施钾肥处理,以探究长江流域各省(市)(四川、云南、贵州、重庆、湖北、安徽、江苏、浙江和上海)冬小麦在优化施肥下的可获得产量、产量反应、相对产量、农学效率和偏生产力特征。【结果】我国长江流域冬小麦优化施肥处理下的平均产量为6.6 t·hm^-2,其中安徽省平均产量水平最高,为7.3 t·hm^-2,重庆市最低,为3.6 t·hm^-2。施用氮、磷和钾肥的平均产量反应分别为2.3、0.9和0...     

新疆艾比湖流域植物区系研究

艾比湖流域目前生态环境问题很严重,突出表现在:盐尘暴天气增多、艾比湖湖面缩小、沙漠化、生物多样性降低、水资源利用不合理、水体污染等。这些对天山北坡经济带会产生威胁,所以对艾比湖流域进行生物多样性研究有重大意义,是非常必需的。对此我们在艾比湖流域进行野外调查,并整理和鉴定植物标本,艾比湖流域共有高等植物1178种,隶属79科440属,其中蕨类植物7科,9属,15种,裸子植物3科,4属,7种,被子植物69科,427属,1156种,其中有2个特有种:艾比湖桦(Betula ebinuricum),艾比湖沙拐枣(Calligonum ebi-nuricumIvanova)。对艾比湖流域的植被进行了地理区系成分分析,结果表明:艾比湖流域治污区系成分复杂,分属于20个类型,以中亚成分、欧亚成分和北温带成分占优势,表明新疆种子植物区系特征与本地区所处的气候带、地理位置及其地史变迁是一致的。这可为艾比湖流域生物多样性研究、生物资源的合理开发和流域生态环境治理提供参考依据。     

黄山浮溪河流域鳞毛蕨科药用蕨类植物资源调查

[目的]调查研究黄山浮溪河流域的毛蕨科药用蕨类植物的种类、分布、药用价值及开发利用情况。[方法]通过对安徽黄山浮溪河流域的蕨类植物资源的初步调查研究,结合我国西南少数民族医药中有关药用蕨类植物资源与少数民族医药中蕨类资源利用情况,对该流域药用蕨类资源中鳞毛蕨科植物的主要种类及其分布情况进行了综合性评价,同时讨论了黄山蕨类植物资源保护及开发利用前景。[结果]黄山浮溪河流域具有药用价值的鳞毛蕨科植物有12种,隶属于3个属。[结论]该研究为进一步开发利用鳞毛蕨科药用蕨类植物资源,保证其药源供应和临床用药安全提供资料。     

花团状纳米铜的表征及抑菌性能研究

以六元瓜环(Q[6])为修饰剂,抗坏血酸为还原剂,硫酸铜为铜源,采用液相化学还原法制备纳米铜。并利用XRD和SEM方法对产物进行了表征,结果显示目标产物为花团状单质纳米铜。然后考察了纳米铜对革兰氏阴性菌大肠杆菌的抑制情况,结果表明,250μg/m L花状纳米铜对大肠杆菌具有良好的抑制作用。     

Effects of dietary lipids on body composition and liver function in juvenile red drum, Sciaenops ocellatus

This study was conducted to evaluate the effects of different concentrations of dietary lipids on body composition and liver function in juvenile red drum, Sciaenops ocellatus. Diets were formulated to contain 40% crude protein from solvent-extracted menhaden fish meal and 0, 7, 14 or 21% lipid from menhaden fish oil. The basal diet, without supplemental fish oil, contained lipid at 0.4% of dry weight. The diets were fed to groups of 25 juvenile red drum initially averaging 7.3 ± 0.18 g fish^–1 in a recirculating culture system for 8 weeks and weight gain was recorded. After an additional 8 weeks, 16 fish from each treatment were sacrificed and the following measurements were recorded: hepatosomatic index (HSI), intraperitoneal fat (IPF) ratio, and liver -tocopherol, malondialdehyde (MDA) formation, and cytochrome P-4501A activity (measured as 7-ethoxyresorufin O-deethylase (EROD) activity). The activity of alanine and aspartate aminotransferases and concentrations of -tocopherol also were measured in plasma.Weight gain was significantly (p<0.05) affected by dietary lipid concentration, with values ranging from 361% of initial weight for fish fed the basal diet to 527% of initial weight for fish fed the diet containing 7% lipid. The HSI and IPF ratio values also were significantly affected by lipid with the lowest values recorded for fish fed the basal diet and the highest values observed in fish fed the diet containing 21% lipid. Increasing dietary lipid significantly increased oxidative stress as reflected in reduced -tocopherol in liver and plasma and increased MDA formation in the liver, although no overt pathological signs were observed. These findings suggest that lipid concentrations between 7 and 14%, when the diet contains 60 IU vitamin E kg^–1, are likely to limit oxidative stress and result in normal physiological responses of red drum.     

加快禄丰县彩云镇林业产业发展的思考

指出了发展林业产业是优化产业结构、培育经济增长点 ,提升区域经济实力、解决经济发展的重要途径 ,是林业产业发展研究的重要课题.针对禄丰县彩云镇当前林业发展格局中存在的问题 ,提出了具体的发展对策.     

Preliminary Study on Eco-environmental Water Demand in Taohuajiang Valley, Guilin

Eco-environmental water demand in Taohuajiang Valley of Guilin is defined as the minimum water volume required by the valley to maintain the eco-environmental quality not to be degraded over time.By using the site survey data,the eco-environmental water demand in Taohuajiang valley is studied preliminarily.The results calculated indicate that: the out-stream eco-environmental water demand is about 14.9 million m3 per year,about 4 percent of annual runoff of the valley;and the in-stream eco-environmental water requirement is about 109.8 million m3 per year,about 30 percent of annual runoff.This study provides scientific basis for local sustainable water resources use and management as well as for eco-environmental water requirement study in similar regions in terms of Karst geological condition and climate.     

Salinity, drainage and selenium problems in the Western San Joaquin Valley of California

Highly productive, irrigated agriculturecan be found in California's Central Valleymade up of the Sacramento, San Joaquin, andTulare Lake basins. High water tablesthroughout much of the San Joaquin andTulare Lake portions of the Valley threatenthis highly productive region. Due totopographic and environmental constraintsmuch of the region is currently withoutdrainage. In 1990 State and Federalgovernment agencies combined to produce areport that outlined possible steps to dealwith the drainage issue. These stepsincluded: 1) Source control (practices toreduce the amount of drainage water); 2)Drainage reuse; 3) Evaporation systems; 4)Land retirement (cease irrigation); 5)Groundwater management; and 6) Discharge tothe San Joaquin River. General backgroundinformation to the history and hydrology ofthe Valley as well as a discussion of thefeasibility and constraints of providingdrainage by discharging drain water to theSan Joaquin River are presented. Inaddition a general discussion of thetechnical and political limitations ofproviding drainage in the River arediscussed.