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1.
目的]探寻不同木荷种源混交林生产力差异的光合机制。[方法]以福建建瓯、江西信丰和浙江龙泉3个木荷代表性种源1年生和2年生幼苗为试验材料,在与杉木混植条件下,设置100%(L0)、50%(L1)和25%(L2)3种光照的光环境,研究3个木荷种源幼苗的生长性状、光合生理及叶绿素荧光特性等对不同光照响应的差异。[结果]1年生和2年生木荷幼苗的苗高、地径和干质量均表现出显著的种源差异,福建建瓯种源幼苗生长优于浙江龙泉种源和江西信丰种源。随着遮阳强度的提高,1年生和2年生2个发育阶段,福建建瓯种源幼苗比叶面积和叶绿素含量等明显增加,叶绿素a/b值、光饱和点、暗呼吸速率和Fo值等均显著降低,表现出较高的形态和生理塑性;相同遮阳处理下福建建瓯种源幼苗总叶面积、叶绿素含量和Fv/Fm值等指标显著高于浙江龙泉种源和江西信丰种源,而叶绿素a/b值、光饱和点、光补偿点和暗呼吸速率则明显低于两种源;长期遮阳和混植状态下福建建瓯种源幼苗可通过较高的生物量分配塑性,增加根系在土壤中分布来响应邻株竞争,进而促进整株干物质的积累;各光环境下,3个木荷种源2年生幼苗Fo、Fm、Fv/Fm和Fv/Fo等叶绿素荧光参数均较1年生幼苗明显升高,但各光环境间差异不显著。[结论]不同木荷种源混交林生产力差异与其对光照的塑性反应能力有关,并随幼苗年龄而变化。 相似文献
2.
【目的】讨论不同产区木荷种源在 NH4+-N或 NO3－-N沉降下的生长表现和响应差异,揭示不同形态氮素对木荷生长发育的影响,为在大气氮沉降环境背景下,选育营养高效利用的木荷速生优质新品种提供理论依据。【方法】以木荷北缘种源区－浙江杭州种源、中部种源区－福建建瓯种源和中部靠南边缘种源区－江西信丰种源3个有代表性的木荷种源作为试验材料,模拟不同形态氮沉降( NH4+和NO3－)增加对不同土壤磷素处理下木荷幼苗生长和叶片氮、磷元素含量的影响。盆栽试验设置土壤低磷(1.1 mg·kg －1)处理和高磷(25 mg·kg －1)对照,以人为喷施 NH4 Cl和 NaNO3溶液进行氮沉降模拟,分别设置3个氮沉降量水平：0,80和200 kg·N·hm －2·a －1,试验按完全随机区组设计,每种源每处理重复12株苗。2013年11月收获,测定苗高、地径等生长指标,并分别测定根、茎、叶各部分干物质量和磷、氮含量。【结果】不同形态氮沉降对木荷苗木生长影响差异显著,磷素可提高种源间对氮素的响应差异。在低磷环境下,不同氮处理下木荷植株生物量和根冠比变异系数较大,这为氮沉降下木荷耐受型植株的选择提供了可能。低磷环境下,NO3－-N 对木荷苗木生长促进作用显著,苗高、地径和生物量分别较 NH4+-N处理高4．5%,17．8%和75．2%,叶片氮、磷含量提高,叶片 N：P 比下降。NH4+-N 对木荷植株的生长抑制作用较强,导致叶片磷含量下降,N：P升高,植株受到磷胁迫增强。而在高磷环境下,NH4+-N的促进作用增强,苗高、地径和生物量分别较 NO3－-N处理高13.5%,10.4%和25.4%。无论土壤在高磷还是低磷环境下,NO3－-N 降低叶片N/P比,而 NH4+-N增加叶片 N/P比。木荷种源间对不同形态氮沉降响应差异显著,在土壤低磷环境下,NH4+-N处理抑制了福建建瓯种源和江西信丰种源生长,生物量下降,而杭州种源却在 NH4+-N80处理下,苗高和地径生长较对照分别增加19%和20%。【结论】在低磷环境下,NO3－-N对木荷不同种源幼苗生长促进作用更强,而当土壤磷含量提高时,NH4+-N的促进作用增强,同时苗木生长差异增大。浙江杭州种源对 NH4+-N 的适应性更强,而福建建瓯和江西信丰种源则对 NO3－-N适应性更强。 相似文献
3.
在海南岛热带山地雨林的演替早期、中期和后期样地共选择30个物种,应用Li-6400光合测定系统测量其光合作用的光响应曲线。计算得出最大光合速率(Amax)、光补偿点(LCP)、表观量子效率(Ф)和暗呼吸速率(Rd)。并测量叶片的比叶面积(SLA)、氮(LN)和磷(LP)含量。结果表明:随着演替进行,最大光合速率(单位面积或单位重量)逐渐下降,次序为演替早期>演替中期>演替后期,但差异不显著(P>0.05);暗呼吸速率(单位面积或单位重量)和表观量子效率逐渐升高,差异也不显著(P>0.05);叶片的比叶面积、叶片氮含量和叶片磷含量都逐渐升高。3个演替阶段共有物种:子楝树(Decaspermum gracilentum)和鱼骨木(Canthium dicoccum)的单位干重最大光合速率、单位干重暗呼吸速率、比叶面积和叶片氮含量随演替进行而逐渐升高,次序为演替早期<演替中期<演替后期。整体上,单位干重最大光合速率和单位干重暗呼吸速率与比叶面积显著正相关(P<0.01);单位干重暗呼吸速率和光补偿点与叶片氮含量显著正相关(P<0.01)。在演替过程中,植物表现出了共同的形态反应,但子楝树和鱼骨木显示出不同的适应策略。 相似文献
4.
对在照度为5000lx、大气CO2体积分数为700×10-6环境下生长3个月的闽楠PhoebebourneiHemsl.Yang进行了研究.结果表明:大气CO2体积分数倍增将使闽楠植株叶片叶绿素含量降低28.7%,其中叶绿素a、b分别下降了28.6%、19.8%,类胡萝卜素上升2.8%,叶绿素a/b从1.95下降到1.55.长期高体积分数CO2处理使叶片可溶性糖含量降低2.45%,可溶性蛋白含量降低53.91%,暗呼吸速率下降95.6%,光呼吸速率下降43.7%;短期内CO2加倍处理,光合速率上升21.76%;长期处理,则下降89%.这表明,短时CO2体积分数加倍处理使植物的表观光合速率明显增加;长期处理明显抑制了闽楠的光合作用,出现了严重的光合适应现象.闽楠光合作用和呼吸作用的减弱致使整个代谢水平下降. 相似文献
5.
弱光桑树幼苗形态结构和光合特性对光强的适应性 总被引：1，自引：0，他引：1
为给桑树的栽培提供技术资料,以桑树品种"秋雨"为试验材料,研究了温室内弱光桑树幼苗移栽到自然光下的光转换过程中叶片、根系和光合的适应性。结果表明:桑树幼苗由弱光(光强相当于自然光强的27%)移栽到大田自然光下的光转换过程中,叶片厚度、栅栏组织厚度和叶绿素a/b比值只略高于弱光叶片,显著低于自然光叶片,而叶绿素含量与弱光叶片相似,显著高于自然光叶片,单株根系干质量和根冠比明显高于弱光叶片。转换光桑树叶片的RuBP羧化效率、光饱和点、光饱和时的光合速率比弱光叶片略高,而明显低于自然光叶片,且表观量子效率较高。移栽10d后,转换光叶片实际光化学效率和热耗散随光强的变化介于弱光叶片和自然光叶片之间,光合能力较低,热耗散能力增强。说明弱光叶片在移栽后的叶片结构和光合功能没有达到自然光叶片的水平,光合能力的提高主要依赖于根系增长和状态转换耗散部分过剩光能以减轻光抑制。 相似文献
6.
为了选筛选出不同光效水平的油茶种质,利用LI-6400便携式光合仪对6个进入盛果期的油茶品种的光合日变化、光响应曲线和CO2响应曲线进行了研究,同时检测了叶片中叶绿素含量和成熟后种籽与果实含油率等经济性状,分析了油茶果实生长期光合特性与经济性状的相关性。结果表明,不同油茶品种间各光合特性参数、叶绿素含量和经济性状指标等均存在差异,‘国油13’和‘湘林210’由于具有较好的光能和CO2利用率、较高的叶绿素含量和含油率等,以及较低的暗呼吸速率,表现出较高的光合效率。最大净光合速率、表观量子效率、羧化效率、光呼吸速率和CO2饱和点与含油率等经济性状呈显著正相关,暗呼吸速率、光补偿点和光饱和点与含油率等经济性状呈显著负相关。 相似文献
7.
为了了解施肥对紫穗槐幼苗叶片光合生理特性影响,并筛选出单独施肥对其影响的最佳浓度,为紫穗槐人工培育提供理论支撑及技术指导。试验采用了氮、磷、钾3因素3水平单独施肥,研究不同施肥处理对紫穗槐幼苗光合色素以及可溶性糖的影响,并对其进行测量、分析和比较。结果表明：所有施肥处理均增加了紫穗槐幼苗叶绿素a、叶绿素b、类胡萝卜素、花青素和可溶性糖的含量,其中施K2,钾的含量为0.75 g/株,紫穗槐叶片的叶绿素a最高;施P2,磷的含量为0.10 g/株,紫穗槐叶片的叶绿素b、类胡萝卜素、花青素最高;施N3,氮的含量为0.93 g/株,紫穗槐幼苗的可溶性糖含量最高。 相似文献
8.
在2005年底,对福建建瓯、浙江淳安和庆元的3年生37个产地的木荷种源试验林进行了全面调查,系统研究了幼林生长和分枝性状的种源差异、种源与环境互作及地理变异模式.结果表明:木荷树高、当年抽梢长度、地径、冠幅及侧枝总数、侧枝长和侧枝粗等分枝性状都存在显著的种源效应,木荷地理种源分化明显.造林区立地生境和造林地立地条件对木荷种源生长影响显著,如福建建瓯点3年生种源平均树高较北缘区浙江淳安点和高海拔山地浙江庆元点分别提高了24.1%和18.0%.木荷树高、当年抽梢长度、冠幅、侧枝总数等存在显著的种源×地点和种源×重复/地点互作,不同种源在各区试点上的生长相对表现差异显著.相关分析表明,木荷生长和分枝性状的地理变异模式因区试点环境条件差异而迥异.在中心分布区的福建建瓯点,种源生长和分枝性状与产地纬度相关性显著,呈典型的纬向地理变异模式,速生种源主要来源于分布区的中南部;在北缘区的浙江淳安点,种源高径生长与产地经纬度相关性较小,仅发现侧枝总数和树冠浓密度与产地纬度呈一定程度的负相关,速生种源主要来源于分布区的中部;而在较高海拔区的浙江庆元点,由于环境相对恶劣,木荷种源生长和分枝性状与产地纬度呈显著的正相关,偏北部种源的早期生长表现较好.基于种源幼林测定结果,分别从中心分布区和北缘区初选了一批速生用材和生物防火优良种源. 相似文献
9.
长白落叶松人工林生理及光合特性对模拟氮沉降的响应 总被引：1，自引：0，他引：1
《辽宁林业科技》2018,(6)
为探讨长白落叶松生理及光合特性对氮沉降的响应规律,比较了不同氮沉降水平下长白落叶松最大净光合速率、叶片养分含量及光合色素含量之间的差异。结果表明:长白落叶松最大净光合速率随氮沉降水平呈先增加后下降的趋势,40 kg·hm~(-2)·a~(-1)中氮处理的最大净光合速率达到最大,继续增加施氮量则出现下降趋势;叶片氮含量随氮沉降水平增加而显著增加(p0.05),叶片磷含量和光合色素含量变化不显著(p0.05)。由此可知,氮沉降增加能够显著增加长白落叶松叶片氮含量,对长白落叶松的光合能力也有一定的促进作用,但这种促进作用存在一定的阈值效应。 相似文献
10.
利用来自7省区36个木荷种源在浙江淳安和福建建瓯两试验点的苗期测定材料,研究其苗木生长、根系特征和叶片形态等12个性状的种源差异及其地理变异模式。方差分析结果显示,除主根长、侧根长和叶片颜色在种源间无显著差异外,其它性状的种源效应都达到显著或极显著水平。种源苗木性状与产地地理气候因子的相关分析发现,苗高、叶片特征(叶片数、叶片宽、叶片厚)及秋末嫩叶颜色等呈典型的纬向变异模式,产地温度则是造成这种纬向变异模式的主要环境作用因子。与北部种源比较,南部种源生长快,叶片数量多,但叶片较薄较窄,其秋末嫩叶颜色变化对寒冷信号反应敏感。影响木荷种子性状表型差异的主导因素是产地的年降水量。以苗高为标准,分别在两地点初选出优良种源10个,它们多来自25°N左右的木荷自然分布区。 相似文献
11.
Oliveira DF Pereira AC Figueiredo HC Carvalho DA Silva G Nunes AS Alves DS Carvalho HW 《Fitoterapia》2007,78(2):142-145
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. 相似文献
12.
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. 相似文献
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14.
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。 相似文献
15.
Growth and physiological response of six Australian rainforest tree species to a light gradient 总被引：1，自引：0，他引：1
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 Amax 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 Amax 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. 相似文献
16.
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. 相似文献
17.
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. 相似文献
18.
Ungulate herbivory of regenerating conifers in relation to foliar nutrition and terpenoid production 总被引：1，自引：0，他引：1
Owen T. BurneyDouglass F. Jacobs 《Forest Ecology and Management》2011,262(9):1834-1845
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. 相似文献
19.
Emile S. Gardiner Magnus Löf Joseph J. O’Brien John A. Stanturf Palle Madsen 《Forest Ecology and Management》2009
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. 相似文献
20.
Insecticidal activity of Vitex mollis 总被引：3，自引：0，他引：3
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. 相似文献