Effects of fruit thinning on ascorbate–glutathione cycle metabolism in black currants (<Emphasis Type="Italic">Ribes nigrum</Emphasis> L.)

To elucidate mechanisms regulating ascorbic acid (AsA) biosynthesis and accumulation in the fruit and leaves of black currants, AsA and the activities of key enzymes in the ascorbate–glutathione (AsA–GSH) cycle were measured from fruit set to fruit ripening during fruit thinning treatments of three common commercial black currant cultivars that differed in their AsA levels: ‘Risager’ (low), ‘Brodtrop’ (medium) and ‘Adelinia’ (high). Treatments were 50% fruit reduction (50% of total fruit set) by hand, control was no thinning. Fruit thinning treatment significantly increased AsA content in fruit of all three cultivars from weeks 2 to 8, significantly decreased AsA content in leaves from weeks 3 to 8. Dehydroascorbate reductase and monodehydroascorbate reductase activities in fruit and leaves had a similar pattern, increasing during week 2, rose until they peaked in week 4. Ascorbate peroxidase activity in fruit in the thinning treatment was slightly lower than in the control. Fruit thinning was shown to be a good model to test AsA biosynthesis regulation and accumulation in black currants. The results from our study provided strong evidence that AsA–GSH cycle involved in AsA synthesis and accumulation in fruit.     

Study of Cr(VI) adsorption onto nitrogen-enriched activated carbon from waste medium density fiberboard

Nitrogen-enriched activated carbons were prepared from waste medium density fiberboard waste by using NaOH, K₂CO₃ and KOH. The content of nitrogen in the activated carbon was 0.92, 0.74 and 1.33 % by analysis. The influence of contact time, pH, Cr(VI) initial concentration and the amount of activated carbon on the Cr(VI) adsorption capacity were investigated. The maximum adsorption capacity of Cr(VI) could reach 89.21 mg/g at pH 2 and a contact time of 9 h. The kinetics adsorption followed nicely the pseudo-second-order rate expression. In adsorption isotherm, the Langmuir model fitted better than the Freundlich model. Pure Poplar activated carbon was also prepared as the adsorbent for Cr(VI) removal as control sample. This study indicated that the nitrogen-enriched activated carbon prepared from waste medium density fiberboard can be used effectively for the removal of Cr(VI) compound from aqueous solutions.     

Application and Prospect of Organic Biocides in Timber Preservation

Organic biocides as timber preservatives have aroused more and more attention,because metal salts especially arsenic,chrome and so on, have been suspected to be poisonous to the soil and aquatic animals,as well as the disposal of preserved timber wastes.Therefore,a number of effective organic biocides have been selected to prevent wood or bamboo from decay,mildew, stain and so on.Most of these products have entered into the market.With people’s increasing awareness of the environmental protection,organic biocides will eventually play important roles in timber preservation in the future.This paper summarized the studies on application of organic biocides as wood or bamboo preservatives,including resistant mechanisms,commonly applied types and effects against wood or bamboo fungi,approaches to detecting the amount of organic biocides in timber and their influences on the environment.Based on the discussion above,the authors predicted the developing prospect of organic biocides in timber preservation.     

腐朽过程中毛竹主要化学成分的变化

以毛竹为原料,选择1种白腐菌和2种褐腐菌对竹材进行腐朽试验,利用X射线衍射和傅里叶红外光谱等手段,测定竹材的失重率、相对结晶度和化学官能团。结果表明,随腐朽时间的延长,竹材的失重率不断增加,结晶度不断下降。通过对腐朽竹材主要官能团的观察,发现白腐菌的侵蚀能造成竹材主成分的分解,其中对木质素的分解能力更强。褐腐菌的侵蚀主要破坏竹材综纤维素。     

GIS在森林资源管理中的应用

以东北林业大学帽儿山实验林场为例,利用GIS软件Arcview3．3、数据库软件Foxpro、图像处理软件Photoshop等工具,建立了帽儿山林场森林资源信息管理系统：并详细介绍了该系统的相关功能。     

金银花在北方地区的栽培技术

金银花(Flos lonicerae)为忍冬科(Caprifoliaceae)忍冬属植物，又名银花、忍冬、双花、二花、苏花等。为常用中药，以未开放的花蕾和藤叶供药用。花蕾，具有清热解毒、散风消肿的功能，主治风热感冒、咽喉肿痛、肺炎、痢疾、痈肿疮疡、丹毒、蜂窝组织炎等症；忍冬藤，具有清热解毒、通经活血等功能，主治湿病发热、关节疼痛、痈肿疮疡、荨麻疹、腮腺炎、     

封杀“入侵者”——国家林业局通报最新外来有害物种防止情况

10月24日，国家林业局召开新闻发布会通报最新外来入侵有害物种刺桐姬小蜂疫情在我国深圳、海南、福建等地发生及防治情况。据国家林业局植树造林司司长魏殿生介绍，刺桐姬小蜂属植食性昆虫，繁殖能力强，生活周期短，1个世代大约1个月左右，1年可发生多代，是2004年定名的新种害虫，主要分布在毛里求斯、夏威夷等地，在我国大陆是新记录。     

大兴安岭地区珍稀野生草本花卉引种驯化

大兴安岭地区地处高寒地带,年平均气温-2℃,极端低温气候导致了该地区城市绿化树种非常单一、绿化花卉资源极度缺乏.为此,我们从2011年开始,先后有目标、有计划的引进珍稀野生草本花卉进行驯化试验,初步筛选确定了观赏价值高、适应性强的优良品种5个,即百合、柳兰、轮叶沙参、石竹、芍药.     

云南省瑞丽市民族竹文化资源及其开发建议

云南省瑞丽市竹类资源丰富,竹林景观独特,有着丰富深厚的竹文化底蕴,具有开发竹文化旅游的优势。文章综合分析了瑞丽市的竹文化资源、开发利用中存在的问题,提出了开发竹文化旅游资源的建议。