部分箬竹属植物的荧光AFLP分析

利用AFLP技术,选择EcoR I/Mse I这一酶切组合,应用9对(EcoR I+3)/(Mse I+3)引物组合进行选择性扩增,检测16种箬竹和5个形态相似的外源竹种的基因组DNA多态性.在21个样品基因组中共获得1 367条清晰的谱带,其中共有条带115条,特异性带273条,特异性缺失条带72条.在16个箬竹样品基因组中共获得1 193条清晰的谱带,其中共有条带190条,特异性带177条,特异性缺失条带98条.这些特异性带或特异性缺失条带可作为识别不同竹种的分子标记.聚类结果表明:所有的箬竹属植物聚成一类,其他5种外源植物聚成一类.此外,AFLP分析提供的分子证据,支持耿氏分类系统(1996),将天目箬竹归入阔叶箬竹中.     

柳树种质资源遗传多样性和亲缘关系的CE-AFLP分析

利用毛细管电泳-AFLP技术,采用EcoR Ⅰ+3/Mse Ⅰ+3和Pst Ⅰ+2/Mse Ⅰ+3引物组合,对从国内外搜集的37份柳树种质资源进行遗传多样性和亲缘关系分析.11对引物共扩增出1 580条条带,多态性条带数为1 399条,多态率在80.65％ ～ 94.67％之间,表明柳树种质间的遗传多样性较高.采用NTSYS-pc 2.10e软件对37份种质进行聚类分析和主成分分析,在相似系数0.63时,37份种质分为2大类,一类是乔木柳,一类除小乔木康定柳外,其余都为灌木柳.聚类分析和主成分分析结果与传统形态分类基本一致,但筐柳组中簸箕柳P295和沙柳基因组水平上差异较大,P295与银芽柳亲缘关系较近.研究结果为柳树分子生物学分类、种质资源保存与利用及品种改良等研究提供理论依据.     

桉树4个种遗传多样性的ISSR分析

以桉树的赤桉、巨桉、细叶桉和粗皮桉4个种18个种源为研究材料,根据优化的ISSR-PCR反应体系和扩增条件,从100条引物中筛选出12条扩增条带特异、条带数适中、背景清晰、重复性好的引物,总计扩增出120条清晰可重复的DNA条带,其中93条是多态性条带。每个引物可扩增的多态条带长度范围为300~2 500 bp,数目在4~11条,平均为7.75条,多态带百分率为77.5%。通过软件POPGENE 1.31、MVSP 32软件和NTSYS-pc软件对所得数据进行分析,从而得出4个种18个种源的遗传相似系数,并绘制分子聚类图和主坐标分析图,结果表明,遗传一致度的变化范围在0.387 1~0.914 0之间,遗传距离的变化范围在0.089 9~0.949 1之间,种间遗传相似性差异较大,种内遗传相似性极高。     

14个油茶良种遗传多样性的SRAP分析

对14个油茶良种进行SRAP标记(序列相关扩增多态性)的遗传多样性分析。采用改良CTAB法提取的油茶叶片基因组DNA为模板,利用优化的SRAP-PCR反应体系,从16个正向引物和20个反向引物中筛选出条带特异、多态性好、稳定性高的8对引物组合。利用这些引物组合对14个油茶良种扩增出65条清晰可重复的条带,其中22条是多态性条带,多态性条带百分率为33.85%。通过生物学软件对所得数据进行遗传学分析,计算出遗传相似系数,绘制出分子聚类图,为油茶良种的后续分子鉴定及分子育种提供了科学基础。     

RAPD标记鉴定银白杨×新疆杨杂交后代

利用RAPD标记对银白杨(♀)×新疆杨(♂)杂交后代及其亲本进行DNA多态性鉴定。结果表明,8对引物共扩增出46条带,平均每对引物扩增出5.75条带,多态性带占扩增总带数的41.3%,扩增片段大小在300~3 000 bp之间。父母本的特异性条带在子代中出现的频率分别为51.25%和46.88%。杂交后代的带型分为叠加型、缺失型和特异型。父母本之间的遗传相似系数为0.652 2,子代8与父本遗传相似系数最高为0.913 0,子代6与母本遗传相似系数最高为0.847 8。本研究从分子水平鉴定杂交种,为开展分子标记辅助杨树杂交亲本选配和杂种子代表现预测奠定了基础。     

湖北三潭风景区野生省沽油遗传多样性的ISSR分析

采用ISSR分子标记技术对湖北三潭风景区野生省沽油群体32个样本进行遗传多样性分析,从18条ISSR引物中筛选出10条引物用于PCR扩增,共扩增出147条DNA条带,其中多态性条带134条,占91.16%,平均每个引物扩增条带的数目为14.7条。利用POPGENE1.32和NTSYS-pc软件分析得出该野生省沽油样本的平均有效等位基因数为1.4319,平均Nei′s基因多样性指数为0.2653,平均Shannon信息指数为0.4118;样本间的遗传相似系数在0.47～0.87之间;UPGMA聚类结果,在遗传相似性系数0.6558处可把供试的32个样本分为3大类,表明该野生省沽油群体的遗传多样性比较丰富。     

四种竹子的RAPD指纹图谱的初步研究

本实验以RAPD技术对考顺竹、凤尾竹、绿竹、白绿竹四个品种用20种已知序列的10nt引物进行PCR反应扩增。其中有17种可扩增出DNA条带,构成RAPD指纹图谱。各种引物PCR扩增的DNA条带数目在0—6条之间,大小在0．3—2．0kb之间。各种竹子的17种引物扩增的DNA条带总数在23—44条之间。四种竹子两两之间的相似系数在36—73％之间。     

邓恩桉遗传多样性的ISSR分析

探讨邓恩桉亲缘关系及遗传多样性,为其种质资源利用和分子育种提供参考。利用ISSR分子标记技术分析邓恩桉6个种源遗传多样性。筛选出8条特异引物共扩增90条清晰条带,其中76条为多态条带,多态性比率为84.44%,平均等位基因观察值为1.8444,平均有效等位基因为1.4928,基因多样性指数为0.2879,Shannon信息指数为0.4306。6个邓恩桉种源遗传相似系数在0.7271~0.8719之间,平均相似系数为0.7926。UPGMA聚类分析发现,在相似系数为0.80时邓恩桉6个种源可划分为2个类群。邓恩桉种源间遗传多样性差异较小,聚类结果与邓恩桉种源地理分布密切相关。     

西种竹子的RAPD指纹图谱的初步研究

本实验以ＲＡＰＤ技术对考顺竹，凤尾竹，绿竹，白绿竹四个品种用２０种已知序列的１０ｎｔ引物进行ＰＣＲ反应扩增，其中有１７种可扩增出ＤＮＡ条带，构成ＲＡＰＤ指纹图谱，各中引物ＰＣＲ扩增的ＤＮＡ条带数目在０－６条之间，大小在０．３－２．０ｋｂ之间，各种竹子的１７种引物扩增的ＤＮＡ条带总数在２３－４４条之间，四种竹子两两之间的相似系数在３６－７３％之间。     

银白杨×马氏杨杂交子代及亲本的AFLP分析

为了探讨银白杨、马氏杨及银白杨×马氏杨杂交子代间的遗传多样性参数及个体聚类关系,利用8对引物对银白杨、马氏杨及银白杨×马氏杨杂交子代4个样本进行了AFLP分析。结果表明,8对引物共扩增出780条扩增谱带,其中多态性条带数为715条,多态性比例为91.65%,平均有效等位基因数为1.5017,Nei’s平均遗传多样性指数为0.3065,Shannon平均信息指数为0.4679。不同杂交子代在E-AAC/M-CAG引物对上均有特异性位点,这些特异位点可用于品种鉴定。聚类研究发现,在相似系数为0.76时,试验样品分成2个AFLP群,其中马氏杨为1个AFLP群,银白杨及2个杂交子代为1个AFLP群;当相似系数为0.78时,银白杨和2个杂交子代的AFLP群又划分为2个亚群,其中杂交子代1和杂交子代2聚合为亚群1,银白杨为亚群2。本研究的结果多态性比例很高,对样品的区分率达到100%,为杨树AFLP分析检测提供了指导借鉴价值。     

Antibacterial activity of plant extracts from Brazilian southeast region

A screening was conducted with 26 plants collected in the Brazilian southeast region, to identify plant extracts with antibacterial properties against Aeromonas hydrophila, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus. Initially, the agar diffusion method was employed. Then, those extracts presenting activity were submitted to a broth microdilution assay to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). It was observed that 13 of the tested extracts showed antibacterial activity. The best results were obtained with those from Lantana lilacina and Phyllanthus tenellus.     

利用三种梢栖真菌生物防治落叶松枯梢病的研究

从落叶松梢栖真菌筛选出对落叶松枯梢病病原菌有抑制作用的菌株,对落叶松枯梢病进行生物防治。将自落叶松梢部分离到的11种梢栖真菌与落叶松枯梢病病原菌进行对峙培养,根据被覆盖程度、抑菌率、拮抗系数和防治预试验的结果,综合评价后发现:粪生粪壳、深绿木霉和球毛壳3种梢栖真菌对落叶松枯梢病有良好的拮抗作用。利用这3个菌株在黑龙江省勃利县通天一林场国富沟进行林间防治试验,结果表明:防治效果为粪生粪壳>代森锰锌400倍液>深绿木霉>球毛壳;深绿木霉和粪生粪壳喷洒浓度50%和球毛壳喷洒浓度75%时,真菌多样性最多,梢栖真菌系统较其他浓度更为稳定,与化学防治相比,既达到了防治目的又具有不污染环境的优势。     

Growth and physiological response of six Australian rainforest tree species to a light gradient

An understanding of growth and photosynthetic potential of subtropical rainforest species to variations in light environment can be useful for determining the sequence of species introductions in rainforest restoration projects and mixed species plantations. We examined the growth and physiology of six Australian subtropical rainforest tree species in a greenhouse consisting of three artificial light environments (10%, 30%, and 60% full sunlight). Morphological responses followed the typical sun-shade dichotomy, with early and late secondary species (Elaeocarpus grandis, Flindersia brayleyana, Flindersia schottiana, and Gmelina leichhardtii) displaying higher relative growth rate (RGR) compared to mature stage species (Cryptocarya erythroxylon and Heritiera trifoliolatum). Growth and photosynthetic performance of most species reached a maximum in 30–60% full sunlight. Physiological responses provided limited evidence of a distinct dichotomy between early and late successional species. E. grandis and F. brayleyana, provided a clear representation of early successional species, with marked increase in A_max in high light and an ability to down regulate photosynthetic machinery in low light conditions. The remaining species (F. schottiana, G. leichhardtii, and H. trifoliolatum) were better represented as falling along a shade-tolerant continuum, with limited ability to adjust physiologically to an increase or decrease in light, maintaining similar A_max across all light environments. Results show that most species belong to a shade-tolerant constituency, with an ability to grow and persist across a wide range of light environments. The species offer a wide range of potential planting scenarios and silvicultural options, with ample potential to achieve rapid canopy closure and rainforest restoration goals.     

Antimicrobial activity of some endemic plants growing in the Eastern Black Sea Region, Turkey

The Eastern Black Sea Region has an extensive flora because of ample rainfall lasting all year. In this study, antimicrobial effects of 74 crude extracts of 22 endemic plants were investigated. Among the 30 active crude extracts, water-insoluble crude extracts from Betula medwediewii, Heracleum platytaenium, Primula longipes, Anthemis cretica ssp. argaea and Centaurea helenioides were the prominent ones with their MIC values.     

Screening of antioxidant activity of three Euphorbia species from Turkey

Euphorbia acanthothamnos, E. macroclada and E. rigida were investigated for their antioxidant activity. The antioxidant potential of extracts of E. acanthothamnos, E. macroclada and E. rigida was evaluated using different complementary antioxidant tests.     

Anti-HBV activities of Streblus asper and constituents of its roots

The extracts from leaves, heartwood, barks and roots of the Streblus asper were investigated for anti-HBV activities, separately. The results suggested that the MeOH extracts of the heartwood, barks, and roots exhibited good anti-HBV activities. Further investigations displayed that ethyl acetate and n-butanol soluble parts of their MeOH extracts showed more significant anti-HBV activities. Moreover, a new lignan, together with 11 known compounds, was isolated from n-butanol-soluble part of MeOH extract of the roots of S. asper. The structures were elucidated by spectroscopic methods, including 1D NMR ((1)H NMR, (13)C NMR), 2D NMR (HMQC, HMBC) and HR-EI-MS experiments. Compounds 1-3 were evaluated for their anti-HBV activities. Honokiol showed significant anti-HBV activity with IC(50) values of 3.14μM and 4.74μM for HBsAg and HBeAg with no cytotoxicity respectively, while lamivudine (3TC, positive control) exhibited weak anti-HBV activity with IC(50) values of 11.81μM and 25.80μM for HBsAg and HBeAg respectively.     

Ungulate herbivory of regenerating conifers in relation to foliar nutrition and terpenoid production

Ungulate browsing greatly influences regeneration dynamics of some forest ecosystems, yet the relationship between browse susceptibility and foliar chemistry of forest tree seedlings is not well understood. We applied field fertilization (15N-9P-10K controlled-release fertilizer at 0, 20, 40, and 60 g per seedling) and investigated how subsequent changes in terpenoid production and foliar nutrition influence ungulate browse preference for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla Raf. Sarg.), and western redcedar (Thujaplicata Donn ex D. Don) seedlings across four sites in northwestern Oregon, USA. Fertilization increased foliar N concentration of all three species, but above-ground growth of only Douglas-fir and western hemlock. Foliar monoterpene concentrations for western hemlock and western redcedar also increased at higher fertilization rates, while Douglas-fir monoterpene production was not affected by fertilization. Regardless of monoterpene levels, ungulate browse preference was greater for fertilized western hemlock seedlings. The opposite response, however, was observed for western redcedar at two of the four study sites where the likelihood of browse was greater for non-fertilized than fertilized seedlings. Differences in browse preference among species may depend on the type and amount of individual monoterpenes manufactured in response to fertilization. Western redcedar produce α- and β-thujone, oxygenated monoterpenes known to promote gastroenteritis and possibly inhibit microbial rumen activity, which were absent from Douglas-fir or western hemlock. Higher concentrations of α- and β-thujone associated with increasing fertilizer rate provide a plausible explanation as to why ungulates preferred non-fertilized western redcedar. Our results illustrate species-specific adaptation in browse avoidance and selective ungulate browsing behavior of individual trees as linked to foliar chemistry.     

Photosynthetic characteristics of Fagus sylvatica and Quercus robur established for stand conversion from Picea abies

Efforts in Europe to convert Norway spruce (Picea abies) plantations to broadleaf or mixed broadleaf-conifer forests could be bolstered by an increased understanding of how artificial regeneration acclimates and functions under a range of Norway spruce stand conditions. We studied foliage characteristics and leaf-level photosynthesis on 7-year-old European beech (Fagus sylvatica) and pedunculate oak (Quercus robur) regeneration established in open patches and shelterwoods of a partially harvested Norway spruce plantation in southwestern Sweden. Both species exhibited morphological plasticity at the leaf level by developing leaf blades in patches with an average mass per unit area (LMA) 54% greater than of those in shelterwoods, and at the plant level by maintaining a leaf area ratio (LAR) in shelterwoods that was 78% greater than in patches. However, we observed interspecific differences in photosynthetic capacity relative to spruce canopy openness. Photosynthetic capacity (A₁₆₀₀, net photosynthesis at a photosynthetic photon flux density of 1600 μmol photons m⁻² s⁻¹) of beech in respect to the canopy gradient was best related to leaf mass, and declined substantially with increasing canopy openness primarily because leaf nitrogen (N) in this species decreased about 0.9 mg g⁻¹ with each 10% rise in canopy openness. In contrast, A₁₆₀₀ of oak showed a weak response to mass-based N, and furthermore the percentage of N remained constant in oak leaf tissues across the canopy gradient. Therefore, oak photosynthetic capacity along the canopy gradient was best related to leaf area, and increased as the spruce canopy thinned primarily because LMA rose 8.6 g m⁻² for each 10% increase in canopy openness. These findings support the premise that spruce stand structure regulates photosynthetic capacity of beech through processes that determine N status of this species; leaf N (mass basis) was greatest under relatively closed spruce canopies where leaves apparently acclimate by enhancing light harvesting mechanisms. Spruce stand structure regulates photosynthetic capacity of oak through processes that control LMA; LMA was greatest under open spruce canopies of high light availability where leaves apparently acclimate by enhancing CO₂ fixation mechanisms.     

Insecticidal activity of Vitex mollis

Organic extracts from the leaves of Vitex mollis were assessed for their toxic effect on fall armyworm neonate larvae (Spodoptera frugiperda), an important insect pest of corn. The extracts showed insecticidal and insect growth regulatory activity, being CHCl(3)-MeOH (1:1) extract the most active, also found to be toxic in the Artemia salina test.