3种松树形态,解剖及叶绿素含量的研究

调查研究了马尾松、黑松、黄松的形态、解剖及叶绿素含量差异。发现黄松的针叶最长；针叶每厘米长鲜重及枝条顶芽色泽接近马尾松，针叶横断面长宽比接近黑松；针叶硬度介于两松之间。黄松针叶黄绿色，其叶绿素总量、叶绿素Ａ及Ｂ均明显低于马尾松或黑松。黄松针叶树脂道数超过马尾松或黑松，叶内２个维管束的排列方式，针叶树脂道中生性及气孔带数目均与黑松相似，针叶色泽与黑松×马尾松的人工杂种（日本的和华松）相似。由于上述特征，黄松为杂种的可能性是存在的。     

不同营林措施对马尾松针叶养分的影响

对设置在贵州龙里、台江以及广西热带林业实验中心的不同施肥、不同密度、不同抚育措施、不同整地方式和不同种源马尾松人工林试验样地内针叶样品的Ｎ、Ｐ、Ｋ、Ｃa、Ｍg含量进行分析研究，结果表明，除广西施肥５年后，不同处理间针叶Ｎ、Ｍg两元素含量具有极显著差异外，其余措施对马尾松针叶养分含量的影响均未达到显著差异水平。因此，施肥具有调节马尾松针叶养分含量的作用；而不同造林密度林地内马尾松个体吸收养分的能力相同，则高密度易造成地力的快速衰退，对长期高密度造林的林地，应加以施肥，以维护土壤的持续利用；抚育措施并不影响林木养分的吸收；整地也未对马尾松吸收养分有多大影响；不同种源吸收养分的特点差异不大，因而优良种源加速林地地力的衰退。     

不同家系马尾松苗木水分参数的研究

应用P -V技术对不同家系马尾松苗木膨压为 0时的渗透势 (φstlp)、充分膨胀的渗透势 (φssat)、膨压为 0时的相对含水量 (RWCtlp)、膨压为 0时的相对渗透含水量 (ROWCtlp)、细胞最大弹性模量 (εmax)和膨压随叶水势下降而下降的速率 (b)等水分参数进行了研究 ,并用反隶属函数的方法对不同家系苗木保持膨压的能力进行综合评价。结果表明各家系马尾松 ψstlp、φssat、RWCtlp、ROWCtlp、εmax和b值都较低 ,显示了较强的保持膨压的能力。综合评价表明 4 5 6、83、2 0家系和台江种源保持膨压的能力最强 ,75、38和 12 7家系保持膨压的能力较强 ,而 2 3、4 6 4和 186家系保持膨压的能力则相对较弱 ,说明马尾松苗木耐旱性存在较大的种内遗传变异。干旱胁迫下 ,对 83家系与 4 6 4家系的研究表明 ,在一定水势范围 ,b值出现一个低值 ,φstlp也有一定程度的下降 ,εmax值有一定程度的上升 ,但升幅不大。说明在一定的干旱胁迫范围内 ,马尾松苗木随着干旱胁迫的加剧渗透调节能力有所提高。     

马尾松家系的叶绿素含量和气孔形态的研究

对马尾松（Pinus massoniana）10个家系的叶绿素含量和气孔形态进行了测定、分析和比较。结果表明：闽北种源比闽西南种源叶绿素含量高，叶绿素a/b值低；气孔密度和孔径呈负相关，10个家系气孔多呈凹状，少数呈突起状。     

马尾松不同家系光合特性的研究

对马尾松１０个家系光合特性的研究表明：（１）不同家系在叶绿素含量，叶绿素ａ／ｂ值，气孔密度，孔径，生物量等方面存在明显差异。（２）生物量和叶纱含量，气孔密度有明显的相关，两者对生物量的贡献达９５％以上；生物量和净光合速率存在一定的正相关。     

成年马尾松针叶水势和形态对隔离降雨的响应

通过在福建省长汀县红壤严重侵蚀区以持续100%隔离降雨模拟水分亏缺环境,研究土壤含水量变化对先锋造林树种马尾松针叶水势、针叶形态的影响,评价马尾松在水分胁迫下的生态适应性及生理调节机制。结果表明:(1)研究期内,处理组20 cm和80 cm土层土壤含水量持续下降并显著低于对照组(P<0.05),差异达10.93%和12.17%,表明土壤环境已出现水分亏缺;(2)处理组针叶水势(Ψd)持续下降,平均值为-3.73 MPa,显著低于对照组-2.80 MPa(P<0.05),证明处理组土壤含水量下降已对马尾松针叶水势产生了显著的影响,且通过拟合土壤含水量与针叶水势关系得出先锋造林树种马尾松具有较强的抗旱能力;(3)马尾松针叶形态相关指标分析表明,隔离降雨第2 a内对照组与处理组间叶长、叶宽、叶面积的差值均明显大于第1 a内,说明生长减缓是该地区马尾松应对土壤水分亏缺的重要途径。     

不同家系马尾松对持续干旱的响应及抗旱性

【目的】了解持续干旱对不同家系马尾松幼苗生长和生理特征的影响,初步揭示马尾松的抗旱机制及抗旱遗传效应,比较不同家系的抗旱能力,为马尾松抗旱优良家系选育提供理论依据。【方法】以3个来自广西和贵州的2年生马尾松家系(GX01、GX02和GZ01)幼苗为试验材料,采用随机区组设计,温室土培盆栽模拟干旱环境,研究持续干旱胁迫对马尾松幼苗生长、渗透调节和抗氧化系统的影响。【结果】随干旱胁迫程度的加重,3个家系马尾松的SOD活性均呈先升后降趋势,各家系在胁迫0~10天存在显著差异(P0.05);POD活性亦呈先升后降趋势,但家系间差异不显著(P0.05);MDA含量变化中GX01呈先升后降趋势,GX02和GZ01呈先降后升趋势,各家系在胁迫5~20天以及第30天存在显著差异(P0.05);脯氨酸含量变化中GZ01呈持续上升趋势,GX02和GX01呈先升后降又再升高的趋势,各家系在胁迫20~30天存在显著差异(P0.05)。连续干旱限制马尾松苗期的生长,3个家系马尾松的苗高和地径的生长以及干物质积累均受到抑制,家系间的苗高生长、地径生长、干物质积累等均存在显著差异(P0.05);连续干旱导致GX01和GX02的根冠比显著高于对照,GZ01亦高于对照,但差异不显著。隶属函数分析得出3个马尾松家系幼苗抗旱性GX01GX02GZ01;灰色关联分析发现,根冠比、苗高与抗旱性关联度最大,其次为MDA和脯氨酸含量,可作为评价抗旱性的主要指标。【结论】马尾松幼苗在轻度干旱胁迫下通过增加保护酶活性抵御干旱;在中、重度干旱胁迫下通过增加渗透调节物质抵御干旱逆境伤害;极重度干旱胁迫下,保护酶活性显著下降,MDA含量显著上升,膜质过氧化伤害严重。干旱胁迫下,马尾松幼苗通过增加地下部分生长、减少地上部分生长以适应干旱逆境。马尾松抗旱性受遗传因素控制,不同家系间抗旱性的差异可能与其不同地理环境长期驯化所形成的遗传差异有关。     

落叶松不同种和日本落叶松不同家系叶片横切面构造及形状的研究

为深入研究落叶松系统发育过程及育种工作，对落叶松不同种和日本落叶松不同家系叶片横切面构造及形状进行了研究。结果表明，它们的叶横切面构造，都是由表皮、叶肉的皱褶细胞、树脂道、机构组织、气孔和维管束组成。下皮细胞数目和分布层次不同、气孔带数和气孔数不同、叶片中段宽度和厚度不同、横切面形状也不同。从针叶下皮细胞分布看，我国长白落叶松和苏联远东分布的长白落叶松，在系统发育上不属同一阶段；日本落叶松和欧洲落     

马尾松半同胞子代测定及早期选择研究

对设在福建省上杭白砂国有林场的83个5年生马尾松半同胞子代测定林进行调查分析,结果表明：参试家系在树高、胸径、材积生长性状上存在明显差异,三个性状的家系遗传力分别为0．3395、0．3614和0．3464,受中等大小遗传力控制。以材积为主要指标,兼顾树高、胸径生长性状,从中初步选择出13个优良家系、20株优良单株,其增产效果明显,可在试验点周边区域推广应用。     

高产脂马尾松、普通马尾松枝、叶的精油与抽出物的初步分析

通过热水蒸煮法测得高产脂马尾松的枝条精油含量高于普通马尾松，而针叶精油含量，两种类型的马尾松无大的差别；枝条精油含量较针叶低．气相色谱分析表明：两种类型的马尾松的精油在组成成份上无大的差别，枝、叶相比，枝条精油的构成成份少．生物检定表明：两种类型的马尾松精油对紫花苜蓿的种子的发芽及幼苗的生长都具有一定的影响，并存在一定的差别。用四种不同极性的溶剂（正己烷、苯、乙醚、甲醇）对枝、叶进行逐次抽出，其中甲醇的抽出物含量最高，针叶的抽出物含量高干枝条的抽出物含量。     

Association of Eucalyptus globulus leaf anatomy with susceptibility to Teratosphaeria leaf disease

Resistance of Eucalyptus globulus juvenile foliage to Teratosphaeria leaf disease (TLD) damage has been shown to be under genetic control. Constitutive traits of juvenile leaves such as stomatal density (counted with wax on and with wax removed), total phenolics, total leaf wax, leaf mass per area (LMA) and leaf anatomical features were assessed to determine differences between pairs of resistant and susceptible families. Anatomic features assessed included cuticle, epidermis, palisade spongy mesophyll and total leaf thickness, as well as palisade cell size, shape and intercellular airspace. One interprovenance, one intraprovenance and two within‐family contrasts were used to compare resistant and susceptible pairs of families of Australian origin. The more resistant families had a significantly higher LMA and smaller percentage airspace compared with susceptible families. It is argued that one of the mechanisms by which E. globulus resists TLD involves the closely packed palisade mesophyll cells that increases LMA and reduces airspace, thereby restricting pathogen spread once infection has occurred.     

Diurnal Course of Gas Exchange and Water Use Efficiency of Platycladus orientalis in the Semiarid Region of the Loess Plateau

The daily gas exchange, stomatal conductance, and water use efficiency of Platycladus orientalis in the test field of Fangshan county of Shanxi Province in the semiarid region of the Loess Plateau were measured with portable Li-6200 gas analysis system in natural conditions. The results showed that the diurnal course of net photosynthetic rate displayed a two-peak pattern, that of stomatal conductance displayed a hollow pattern, and that of transpiration rate displayed a signal-peak pattern. Water use efficiency culminated in the early morning. On the basis of two criteria of stomatal limitation of photosynthesis suggested by Farquhar and Sharkey, the predominant limiting factor of photosynthesis was the stomatal conductance of stomatal limitation in the morning (10:00–12:00). However, the midday depression of photosynthesis at noon (12:00–14:00) and the decrease in photosynthesis in the afternoon (16:00–18:00) were the results of nonstomatal limitation, such as low carboxylation capacity of the leaf mesophyll.     

生长抑制剂对大叶黄杨形态及光合作用的影响

目的]探究抑制剂对大叶黄杨生长的抑制作用以及对其叶片形态和光合作用的影响,为灌木绿篱的化学修剪提供技术指导。[方法]在北京林业大学林场苗圃采用3种生长抑制剂(多效唑(PP_(333))、三碘苯甲酸(TIBA)以及脱落酸(ABA))对密植成绿篱状的1年生大叶黄杨扦插苗进行叶面喷施,对其生长、叶片形态及光合作用等指标进行测定。[结果]3种抑制剂均有矮化植株、抑制新梢生长的作用,矮化效果最佳、抑制作用最强的为PP_(333),且高浓度PP_(333)对于高生长的抑制作用持效性较长。叶宽、叶厚以及叶面积在短期PP_(333)处理下高于对照。PP_(333)能提高大叶黄杨净光合速率,主要通过增加叶厚、气孔导度、叶肉导度及叶绿素含量来实现,并且PP_(333)使蒸腾速率提高的同时降低了水分利用效率。TIBA有显著减小叶长、叶宽的作用,但能使叶厚增加,且随浓度的增加作用效果增强,主要通过减小叶面积,降低叶肉导度、气孔导度、胞间CO_2浓度及叶绿素含量来降低净光合速率。ABA能增加叶面积(10 mg·L~(-1)处理除外)、叶长以及减小叶片厚度,通过抑制气孔导度、叶肉导度、叶绿素含量降低净光合速率。TI-BA及ABA均通过降低蒸腾速率,使水分利用效率提高。[结论]3种抑制剂均有矮化植株、抑制新梢生长的作用,并且影响叶片发育,进而影响叶片光合作用,且800 mg·L~(-1)的多效唑对大叶黄杨具有较好的正向作用。     

Effects of foliar nitrogen concentration on photosynthesis and water use efficiency in Douglas-fir

Leaf-level physiological processes were studied in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) to determine whether apparent increases in stand-level water use efficiency (WUE) observed in response to nitrogen (N) fertilization were attributable to foliar N effects on carbon fixation rates or on stomatal control of water loss. Photosynthesis and transpiration were measured at different light intensities and ambient CO(2) molar fractions and comparisons were made between current-year shoots with average foliar N concentrations of 1.58% (High-N) and 1.25% (Low-N). Photosynthetic rates and foliar N concentrations were positively correlated. In response to light, photosynthesis and stomatal conductance were closely coupled and a similar coupling was observed in response to different ambient CO(2) concentrations. Partitioning the photosynthetic responses into mesophyll and stomatal components indicated that foliar N altered mesophyll conductance but not stomatal control of water loss. High-N shoots had significantly greater rates of photosynthesis and transpiration than Low-N shoots and, as a result, instantaneous WUE did not differ significantly between High-N and Low-N shoots.     

Stomatal and mesophyll limitations of photosynthesis in black spruce seedlings during multiple cycles of drought

Container-grown black spruce (Picea mariana (Mill.) B.S.P.) seedlings were planted in trays containing a sand and peat mixture, and placed in a climate-controlled greenhouse. One group of seedlings was kept well-watered, and another group was subjected to three cycles of drought. Gas exchange analysis showed that mesophyll photosynthetic function was largely unimpaired by drought. In contrast, stomatal conductance was sensitive to drought, although it became less sensitive with each drought cycle. Both stomatal and mesophyll conductances increased with time in control and drought-stressed seedlings, but mesophyll conductance increased with time more rapidly than did stomatal conductance. Limitation of photosynthetic rate was dominated by the mesophyll. In control seedlings, relative stomatal limitation increased from 6 to 16% by the end of the experiment. In drought-stressed seedlings, relative stomatal limitation of photosynthesis reached 40% during the first drought, but decreased to near control values immediately after rewatering. Because the third, most severe drought had only a minor effect on stomatal conductance, relative stomatal limitation of photosynthesis was similar to that in control seedlings by the end of the experiment. Inhibition of ontogenetic change during drought stress may be responsible for the apparent acclimation of mesophyll photosynthetic processes. We conclude that it would be more effective to select for high photosynthetic capacity than for reduced stomatal sensitivity when breeding for increased drought resistance in black spruce seedlings.     

Age-related trends in red spruce foliar plasticity in relation to declining productivity

Phenotypic plasticity in needle morphology with increasing tree size and age was investigated by comparing four age classes of red spruce (Picea rubens Sarg.) ranging from juvenile (3-12 years old) to mature (over 100 years old). With increase in tree age there were significant increases in leaf mass per unit area (LMA), mesophyll and vascular bundle area as a percentage of total needle cross-sectional area, and stomatal density. Within the vascular bundle, both xylem cross-sectional area and tracheid lumen area increased significantly, whereas air space as a percentage of total cross-sectional area decreased. These morphological changes were associated with a significant decrease in photosynthetic capacity and stomatal conductance, and an increase in (13)C enrichment. Although both photosynthetic capacity and whole-tree conductance decreased significantly between age classes 3 and 12 years, they did not differ between age classes 53 and 127 years, even though needle (13)C enrichment was significantly greater in the 127-year age class. Thus there appear to be compensatory mechanisms that maintain photosynthetic capacity as trees increase in size and vascular complexity, which in red spruce and other species, may affect leaf hydraulic conductance. Although increased LMA may contribute to reduced photosynthetic capacity in red spruce, similar relationships are not seen in other conifers.     

榆属树种的叶子结构与抗虫性的关系

榆树是我国重要的造林树种，在全国各地尤其是“三北”地区有大面积栽植。但最近几年来，榆树一直遭受着严重的虫害，特别是食叶害虫榆蓝叶甲，使榆树的生长发育和木材产量受到严重的影响。因此，选育抗虫品种和进行科学管理已成为当务之急。据观察，榆树在遭受虫害后，不同的树种或同一树种的不同无性系间的受害程度差别很大，是什么原因引起受害程度的不同呢？现有的研究己清楚指出，物理因素和化学因素共同构成了植物抵御害虫的防御体系。植物可以利用存在于它们组织的，经长期进化而形成的物理因素（形态结构）来阻止或破坏害虫的为害。本研究采用了电镜扫描和石蜡切片法，结合生物测定和田间调查，分析了榆属树种的叶子结构与其抗虫性之间的关系。结果表明，①榆属树种的气孔以大密度分布在叶子的下表面，气孔的保卫细胞具有角质层和木质化的壁。这种特点使幼虫不易从叶子下表面取食到叶肉，所以它们往往转移到叶子上表面取食，从而造成叶子上表面的结构特点与抗虫性的强弱直接相关；②抗虫性强的树种或无性系的叶子表面有很厚的蜡质层，而易感虫的树种或无性系的叶子上表面蜡质较薄。下表面无此规律；③叶子上表面的表皮毛密度（Ｘ１）和角质层厚度（Ｘ２）与叶面积受害指数（Ｙ）呈高度负相关（     

Observation of the scale of patchy stomatal behavior in leaves of Quercus crispula using an Imaging-PAM chlorophyll fluorometer

Patchy stomatal closure occurs in plants with heterobaric leaves, in which vertical extensions of bundle sheath cells delimit the mesophyll and restrict the diffusion of CO(2). The scale of patchy stomatal behavior was investigated in this study. The distribution of PSII quantum yield (Φ(II)) obtained from chlorophyll fluorescence images was used to evaluate the scale of stomatal patchiness and its relationship with leaf photosynthesis in the sun leaves of 2-year-old saplings of Quercus crispula Blume. Fluorescent patches were observed only during the day with low stomatal conductance. Comparison of numerical simulation of leaf gas exchange and chlorophyll fluorescence images showed that heterogeneous distribution of electron transport rate through PSII (J) was observed following stomatal closure with a bimodal manner under both natural and saturated photosynthetic photon flux densities. Thus, fluorescence patterns can be interpreted in terms of patchy stomatal closure. The mapping of J from chlorophyll fluorescence images showed that the scale of stomatal patchiness was approximately 2.5-fold larger than that of anatomical patches (lamina areas bounded by bundle sheath extensions within lamina). Our results suggest the spatial scale of stomatal patches in Q. crispula leaves.     

水分胁迫下中东杨气孔运动与保卫细胞离子含量变化的关系

中东杨插条苗经水分胁迫处理后,在扫描电下观察了气孔开度的变化,并用扫描电镜结合Ｘ＝射线能业微分析技术,分析了保卫细胞中的离子含量变化。结果表明,随着水分胁迫强度的增大,气孔开度变小,气孔趋于关闭。伴随着气关闭,保卫细胞中最明显的变化就是Ｋ＾＋、Ｃｌ＾－含量的下降一Ｃａ＾２＋含量的上升。这个结果表明Ｋ＾＋、Ｃａ＾２＋等离子参与了气孔运动,Ｋ＾＋、Ｃａ＾２＋的移动在膨压运动及气孔七闭现象中起着十分重要     

Response of Platanus orientalis leaves to urban pollution by heavy metals

Atmospheric pollution is an important concern in urban environments.The impact of urban pollution on the physiological,biochemical and anatomical properties of leaves of oriental plane(Platanus orientalis L.)was studied.The leaves were collected from an urban site(Tehran,Iran)and a non-urban forest park(Chitgar Forest Park).Anatomical(stomata,parenchyma,and cuticle)and physiological(chlorophyll content,enzyme activities)properties were analyzed.The concentrations of Cd(cadmium),Pb(lead),Ni(nickel),and Cr(chromium)in leaves were significantly higher and Zn(zinc)lower at the urban site relative to the forest park.Chlorophyll a,total chlorophyll,and carotenoid content in leaves of the urban site were significantly less than those of the forest park,but there was no significant difference in chlorophyll b.In addition,the activities of superoxide dismutase,catalase,ascorbate peroxidase,and guaiacol peroxidase in urban leaves were significantly higher than in the leaves of the forest park.In the urban area,leaves experienced a significant decrease in leaf surface area,stomata density,stomata pore area,epidermis,and spongy mesophyll thickness,but a significant increase in cuticle and palisade thicknesses relative to forest park leaves.The increase in enzyme activities may indicate that the trees are attempting to cope with increased reactive oxygen species(ROS)because of pollution-induced stress.Our study suggests that oriental plane trees alter their physiological and anatomical properties when living in a polluted urban environment.