利用地径建立林木材积估测模型的探讨

通过实测铁杉、红桦和湖北花楸的地径、胸径、树高和材积，我们建立了根据林木地径估测树木材积的数学模型，具有较高的相关系数，可以应用于森林资源管理和森林生态系统研究。     

油茶皂素抑菌效果研究

用溶剂法提取油茶枯饼中的皂素 ,以油茶皂素为材料对大肠杆菌 ,桔青霉 ,黑曲霉 ,金黄色葡萄球菌 ,和 117产朊假丝酵母进行了抑菌试验。结果表明 :均有抑制作用 ,其中对大肠杆菌和黑曲霉抑制作用较强 ,对金黄色葡萄球菌无抑制作用。对有效菌的最小抑制浓度在 0 .6 2 5 %以下     

黑冠山雀Parus rubidiventris的巢址特征与繁殖行为

2007年6月,作者在甘肃尕海—则岔自然保护区发现一个黑冠山雀Parus rubidiventris的洞穴巢址并对繁殖行为作了记录。巢址位于云杉树基下,大小27 cm×11 cm、巢深17 cm。巢材由苔藓、草茎须根、羊毛、云杉叶等组成。黑冠山雀育雏频率1次/1.5 min,食物为膜翅目、鳞翅目昆虫。此外,还发现育雏结束后亲鸟有清除巢内异物行为。     

樟树溃疡病综合防治研究

樟树溃疡病菌为弱寄生茵，主要从植株伤口和衰弱组织侵入。在防治上应采取以营林技术措施为基础，以减少创伤，提高植株抗病力为主的综合防治措施；即(1)选用健壮无病苗木；(2)选择土壤肥沃、湿润、深厚、排水良好的中性或微酸性土壤的林地造林；(3)避免植株机械损伤和日光灼伤；(4)在子囊孢子释放初期喷施70％甲基托布津1000倍液、40％多茵灵1000倍液、70％代森锰锌500倍液或等量式波尔多液等药剂保护；植株发病后和整枝伤口处，喷施70％甲基托布津1000倍液或40％多茵灵1000倍液等药剂。     

落叶松红腹叶蜂食叶量、发育进度及防治适期的研究

掌握科学合理的防治时机，是害虫防治的关键技术之一。为此笔者在对落叶松红腹叶蜂防治技术的研究中，根据落叶松红腹叶蜂幼虫的生物学特性，创新采用拟自然态研究方法、自然产卵小群统计方法，对幼虫每虫和分龄期食叶量(率)、卵和幼虫发育历期、幼虫自然死亡率、越冬幼虫化蛹发育进度及化蛹历期等进行了系统研究。在这些研究的基础上，提出科学的防治适期应为幼虫发育高峰后第7～10d，在此时间内林间可见卵及幼虫约占当年种群数量的76％～90％，是卵和幼虫出现最多的时段，是最大限度地消灭叶蜂幼虫、压低种群数量的有利时期。     

油桐根腐病病原菌的研究

油桐根腐病是油桐林的一种毁灭性病害。形态学和培养性状研究表明,致病菌为腐皮镰孢(Fusarium solani(Mart.)Sacc.)。将该菌与国内供试8个腐皮镰孢专化型菌株比较可看出,菌落生长较快,大型分生孢子短而粗,是一种短粗类型。其次,人工接种试验得知,此菌不侵染6科7属7种供试的专化型寄主植物;又经8个专化型菌株接种油桐试验,也不发生侵染关系。此菌仅侵害大戟科油桐属的油桐,是一种专化性病菌。再次,采用聚丙烯酰胺凝胶电泳分析表明,此菌与供试菌株的脂酶同工酶的谱带特征和相对迁移率均有明显的差异。由此,将油桐根腐病鉴定为腐皮镰孢一新的专化型,命名为油桐腐皮镰抱(Fusarium solani (Mart.) Sacc. f.sp.aleuritidis Chen et Xiao f.sp.nov.)     

Resistance against oxidative stress in leaves of young beech trees grown in model ecosystems with different soil qualities, elevated CO2, and lachnid infestation

Summary The aim of the present study was to investigate whether the resistance of beech foliage(Fagus sylvatica) against oxidative stress was affected by soil quality, nitrogen or CO₂ fertilisation, or lachnid infestation(Phyllaphis fagi). For this purpose young beech trees were grown for four years in reconstructed calcareous or acidic forest soils in open top chambers under ambient or elevated CO₂ concentrations with two levels of nitrogen fertilisation. At harvest lachnid colonisation was observed, preferentially on leaves from trees in calcareous soil and on leaves from trees fertilised with the high nitrogen level. General leaf characteristics such as pigment concentrations, dry mass, and leaf mass ber area were not affected by the soil type, nitrogen fertilisation or CO₂ regime. Leaves colonised with lachnids displayed slightly increased leaf mass per area. When the stress resistance was challenged by exposure to paraquat — a herbicide inducing oxidative stress — leaves from trees grown on calcareous soil maintained significantly longer membrane integrity and, thus, were better protected against stress than leaves from trees on acidic soil. Other experimental variables had negligible or no effects on the resistance against oxidative stress.      

Determination of drought tolerance using root activities in Robinia pseudoacacia ''Idaho'' transformed with mtl-D gene

Idaho locust (Robinia pseudoacacia 'Idaho') is an exotic multi-purpose tree used in landscaping, soil and water conservation, fodder sources and others. To improve its drought tolerance for reclaiming arid land, five lines of transformed mtl-D gene, as osmotic regulator in plant cells, have been selected and managed to determine their drought tolerance under experimental conditions.Qualitative and quantitative variables of transformed plants were studied. The critical value of drought tolerance was determined by detecting the 2,3,5-triphenyl tetrazolium chloride (TTC) reductants in roots and soil water content (SWC). The critical value for drought tolerance was SWC 6% while for the control plants the critical SWC was 8%; a moderate level of SWC is 13% and the highest SWC for plant endurance was 18%. The method proved to be reliable and sensitive in the evaluation of drought tolerance for forest trees.     

刚毛柽柳 TheIF1A 基因的互作蛋白及其表达模式分析

翻译起始因子是一类翻译起始所必需的特异蛋白因子,前期研究表明柽柳翻译起始因子 (TheIF1A) 基因能对外界盐和干旱等非生物胁迫做出响应,且过表达 TheIF1A基因能提高酵母和烟草的抗旱耐盐能力。为进一步研究TheIF1A基因的抗逆机制,本研究通过酵母双杂交对柽柳翻译起始因子(TheIF1A) 基因的互作蛋白进行了筛选,共获得5个互作蛋白,分别为RNA聚合酶β II亚基 (RNA polymerase beta II subunit)、ATP合成酶CF1α亚基蛋白 (ATP synthase CF1 alpha subunit protein)、细胞色素b6/f 复合物亚基IV(cytochrome b6/f complex subunit IV)、核酮糖1,5-二磷酸羧化酶/加氧酶小亚基蛋白(ribulose 1,5-bisphosphate carboxylase/oxygenase small subunit)和组蛋白乙酰转移酶(histone acetyltransferase)。利用实时荧光定量PCR对这5个蛋白基因及 TheIF1A 基因在盐和干旱胁迫处理下的表达模式进行分析,结果表明:这些蛋白基因在盐和干旱胁迫下的表达模式与 TheIF1A基因基本一致,表明TheIF1A可能通过与这些蛋白相互作用来参与逆境胁迫应答。为进一步研究TheIF1A 基因的抗逆机理奠定了基础,有利于完善林木抗逆机制的研究,并为通过基因工程手段提高林木抗逆性提供了候选基因。     

Supercritical fluid extraction of sapogenins from tubers of Smilax china

Supercritical CO(2) fluid extraction (SFE-CO(2)) was used to extract the sapogenins after acid hydrolysis from Smilax china tubers. The influence of extraction variables, such as modifier, pressure, temperature and extraction time, were studied. SFE-CO(2) was found to produce higher yield than conventional solvent extraction. The highest yield (0.454%) of sapogenins, mostly containing diosgenin, was obtained using 35 MPa pressure, 65 degrees C and 95% EtOH as a modifier for 180 min, higher than that obtained with conventional extraction methods (0.385%).