大唼蜡甲人工大量饲养的主要影响因素及其控制

通过对从比利时引进的红脂大小蠹Dendroctonus valens捕食性天敌-大唼蜡甲Rhizophagus grandis Gyll.5年的室内大量饲养,对影响该天敌的产卵量、生长发育和羽化的主要生物因子和环境条件等进行了深入研究。对发现的影响其正常繁殖和生长发育的主要有害生物进行了外部形态、为害特点及控制进行了初步的研究,成虫平均羽化率从2003年的29.61%上升到了2004年的76.03%。研究表明,大唼蜡甲室内大量饲养的主要影响因子有:两种寄生螨(Proclaelapssp.和Histiostomasp.)、球孢白僵菌Beauveria bassiana、种群退化和温湿度条件。严格的卫生条件、病原生物的有效控制和种群复壮是保证大唼蜡甲群体饲养成功的关键。     

不同栽培基质对毛木耳菌丝体生长的影响

[目的]研究不同栽培基质对毛木耳菌丝体生长的影响。[方法]按不同树种(油桐)、木屑粒径、有无淋洗以及是否添加杏鲍菇菌渣,设计14个处理,观察毛木耳菌丝体生长情况。[结果]尾巨桉粗木屑耳袋菌丝密度大、长势好,前期生长速度快、中后期略显后劲不足;木屑不淋洗处理菌丝的生长速度总体较快,前期生长速度慢、中期快、后期明显减慢,与淋洗处理相反;尾巨桉木屑添加杏鲍菇菌渣后,生长速度总体较慢,生长后期后劲不足;油桐木屑菌丝生长总体优于尾巨桉。[结论]该研究可为毛木耳栽培基质的筛选提供参考。     

不同巨桉林下紫色土壤抗蚀性与土壤因子的耦合关系分析

为揭示耕地退耕成巨桉林后对土壤抗蚀性的影响,在野外调查和室内分析的基础上,以紫色土上栽培的6a生巨桉纯林、巨桉+果树、巨桉+粮食作物及农耕地土壤作为研究对象,利用主成分方法分析了影响巨桉林土壤抗蚀性的主要理化指标,同时结合灰色关联度构建了抗蚀性指数—土壤理化性质指标的耦合模型,对不同巨桉林的抗蚀性进行综合判定。结果表明:影响土壤抗蚀性的主要因子有0.25mm团聚体含量、容重、有机质、平均重量直径、水稳性指数、有效钾、碱解氮,其中0.25mm团聚体含量是决定土壤抗蚀性水平的最关键因素;平均重量直径和水稳性指数与土壤理化性质指标分别属于中等和较强关联,土壤理化性质对土壤抗蚀性的影响依次为0.25mm团聚体含量碱解氮有效磷有机质有效钾容重;土壤抗蚀性与土壤理化性质系统的整体耦合水平属于弱协调,系统耦合协调程度为巨桉纯林(中度协调)耕地(弱协调)林粮(轻度不协调)林果(轻度不协调)。研究结论可为耕地退耕成巨桉林地的土壤抗蚀性评价提供一定的理论依据。     

钙与硼、氮配施对酸性土壤上柚木无性系苗期生长的影响

采用311-A混合最优回归设计,以强酸性赤红壤为培养基质,开展柚木苗期Ca,B,N营养元素配比盆栽试验。结果表明:不同配比处理对柚木无性系幼苗高和地径生长,叶、茎、根生物量影响均达极显著水平。Ca是促进酸性赤红壤柚木苗木高、地径生长和叶、茎、根部器官生物量积累的营养因子,也是柚木苗木生长的限制因子。B对苗木生长影响不显著,Ca与B之间不存在交互作用。苗木对N反应敏感,在低Ca量和不施Ca的情况下,随追施N量的增加,苗高、地径生长和总生物量积累受到抑制。贫瘠强酸性赤红壤上培育柚木,应适当增加Ca(氧化钙)和减少N(尿素)的用量。柚木苗期最适Ca,B,N配比为:Ca∶B∶N=1.2g·kg-1∶0.4mg·kg-1∶0.3g·kg-1,相应最佳营养物质配比为:CaO∶H3BO3∶(NH2)2CO=1.68g·kg-1∶2.3mg·kg-1∶0.65g·kg-1。     

漳州琯溪蜜柚果实黑斑病菌的分子鉴定

2008年从漳州采集到疑似由柑橘球座菌(Guignardia citricarpaKiely)引起的黑斑病症状的溪琯蜜柚(Citrus grandis(Linn.)Osbeck cv.guanxi-miyou)果实。使用柑橘球座菌(G.citricarpa)特异引物对该果实上的病斑进行PCR检测及序列分析。PCR检测结果表明从溪琯蜜柚果实病斑上扩增到约490bp的条带。序列分析结果表明,与已知的亚洲柑橘叶点霉(Phyllosticta citriasiana)、G.citricarpa和G.mangif-erae的相应序列同源性分别为99.8%、98.2%和94.0%。该序列含有部分的内转录间隔区1(ITS1)、5.8S核糖体RNA基因(5.8S rRNA)和部分的内转录间隔区2(ITS2)序列。结果表明,引起溪琯蜜柚果实病害的病原菌并不是G.citricarpa,而是一种新描述的病原菌——亚洲柑橘叶点霉(Phyllosticta citriasianaWulan-dari,Crous&Gruyter),该病原菌引起的病害称为柑橘褐斑病。     

桉树与越南安息香混交造林效果研究

对闽南山地尾巨桉与越南安息香人工混交造林试验效果进行调查研究,结果表明:尾巨桉与越南安息香混交是成功的,造林密度为1 350株/hm2,桉树与越南安息香以6∶4星状混交,林分空间分布格局合理,充分利用了营养空间,提高了林分产量和质量。4.5年的混交林分中尾巨桉的平均树高、胸径及单株材积分别比其纯林提高5.20%、11.49%和29.32%,而越南安息香的各项生长指标也明显高于其纯林。尤其是混交林中不论是尾巨桉还是越南安息香,小于10 cm小径木比例均比各自纯林减少,而12～18 cm中径木比例增加,并出现了大于20 cm的大径木,这对培育桉树大径材相当有利;此外,混交林在改良土壤、增强林分抗性等方面均比纯林有明显优势,对维护桉树人工林地力具有现实意义,可进一步推广示范。     

Partial Characterization of Chitinolytic Extract from Endophytic Streptomyces sp. and Its Effects on the Boll Weevil

The present study achieves the biochemistry partial characterization of the chitinolytic extract produced by an endophytic Streptomyces sp. strain （A8）. This extract was also tested against Anthonomus grandis, the cotton boll weevil aiming its control. The chitinase crude extract from the A8 strain was cultured for five days in a minimum liquid media supplemented with chitin. The extract was partially characterized by standard methods. The chitinolytic extract had an optimum temperature of 66 ＂C and an optimum pH between 4 to 9 （around 80% of relative activity）. We also characterized the temperature and pH stability and measured the effects of enzyme inhibitors. The filtered chitinolytic extract was added to an artificial boll weevil diet. Boll weevil development from the egg stage to the adult stage was prolonged, and the percentage of adults that emerged was approximately 66% less than on control diet. This study showed that the.larval development of A. grandis was inhibited by the presence of characterized chitinolytic extract in artificial diet. This work provides an experimental basis for using the chitinase from an endophytic bacterium Streptomyces sp. as a biocontrol alternativeto controlling the plant pest A. grandis.     

尾巨桉提纯复壮初步研究

以尾巨桉DH32-29最低位的萌芽条为外植体,利用组织培养进行继代重复培养(不少于5次),对比分析尾巨桉提纯复壮效果。结果表明:复壮苗与经过继代3年的未复壮苗相比,其继代周期缩短6d,增殖倍数提高1.09倍,生根率提高17.31%,移栽成活率提高20.19%,较未复壮苗有一定优势。     

Verbascoside isolated from Tectona grandis mediates gastric protection in rats via inhibiting proton pump activity

Evidences have suggested that Tectona grandis (TG) attenuates gastric mucosal injury; however its mechanism has not yet been established. The aim of present study was to evaluate the gastroprotective mechanism of ethanolic extract of TG (E-EtOH), butanolic fraction (Fr-Bu) and to identify its active constituents. Anti-ulcer activities were evaluated against cold restraint (CRU) and pyloric ligation (PL) induced gastric ulcer models and further confirmed through H⁺ K⁺-ATPase inhibitory activity. Cytoprotective activity was evaluated in alcohol (AL) induced gastric ulcer model and further through PGE₂ level. E-EtOH and Fr-Bu attenuated ulcer formation in CRU. Moreover E-EtOH and Fr-Bu displayed potent anti-secretory activity as evident through reduced free acidity and pepsin activity in PL, confirmed further by in vitro inhibition of H⁺ K⁺-ATPase activity. In addition cytoprotective potential of E-EtOH and Fr-Bu were apparent with protection in AL model, increased PGE₂ content and enhanced mucin level in PL. Phytochemical investigations of Fr-Bu yielded terpenoides and a phenolic glycoside, verbascoside. The anti-secretory mechanism of verbascoside mediated apparently through inhibition of H⁺ K⁺-ATPase with corresponding decrease in plasma gastrin level, is novel to our finding. Gastroprotection elicited by TG might be through proton pump inhibition and consequent augmentation of the defensive mechanism.     

巨桉萌芽更新试验研究

通过对巨桉皆伐迹地进行萌芽更新试验,结果表明:巨桉第一代伐桩萌芽率达98.7%,1年生萌芽林树高、胸径分别比同龄实生林提高273.3%、390.0%;4年生树高、胸径、单株材积、蓄积分别比同龄实生林提高18.9%、24.3%、74.7%和54.0%,单位面积、单位蓄积造林更新费用分别仅为同龄实生林的67.6%、43.9%,经济效益明显。