人工种植省藤的性能特征

对人工种植的棕榈藤和野生藤的力学特性进行对比。同时,评估了比重和纤维比对强度的变异性的影响,并评估了强度特性对藤龄的影响。人工种植和野生藤的断裂模数和弹性模数相似,由此证明人工种植藤的强度特性并不亚于野生藤的强度特性。这说明,人工藤可在工业上利用,且对藤产品的性能没有负面影响。绝干比重和纤维比也没有对其强度特性的变异性产生影响。同样,藤龄也不会对强度特性产生影响。很明显,幼龄藤也具有成熟藤秆相同的强度。     

日本紫色甘薯品系的形态标记聚类分析

根据通用的甘薯鉴定性状及其生长期记载标准,选择26项指标作为形态鉴定参数对14个日本紫色甘薯品种(系)进行聚类分析.结果表明,所有供试品系或品种分成6类."山川紫"和新引进的13个日本紫色甘薯品系之间的亲缘关系相对较远;在新引进的日本紫色甘薯中,A组中A1、A2、A7等3个品系之间以及A3、A4、A6等3个品系之间的亲缘关系很近;B组中B1～B3与B7～B8的亲缘关系很近.     

石栎属和栎属5个树种的幼苗形态特征

就壳斗科中的石栎属和栎属5个树种的种子(果实)及幼苗的整个发展过程和种子、苗木的生产技术做了细致的研究,并对各树种的种子及幼苗进行观察、记载和绘制成图。     

芨芨草形态特征及人工栽植技术

芨芨草是高大的多年生密丛大型丘状下繁禾草。它适应性强 ,耐盐碱、耐寒、耐旱 ,根系发达 ,是优良的牲畜饲料和优质的造纸原料 ,目前已在新疆、内蒙等地开展人工栽植。该文通过介绍芨芨草的形态特征、生长特性及人工栽植技术 ,为芨芨草栽植提供技术参考。     

4种野生芍药的花粉形态研究

花粉和孢子,同其他的生殖器官一样,较少受环境的影响（埃尔塔曼,1978;王开发等,1983）,其形态属于比较稳定的性状。近些年来,不少学者借助扫描电镜观察园艺植物的花粉形态,阐释了许多园艺植物种间或品种间的亲缘关系（张秀英等,1997;吕华飞等,1994;袁涛等,1999）。关于芍药（Paeonia）的该项研究,报道很少（席以珍,1984）。本文以采自野外的4个种（居群）的花粉为主要研究材料,建立了芍药花粉形态的量化指标。     

江南油杉及中国油杉属植物的形态特征识别

油杉属植物是我国南方的珍贵用材树种和园林绿化树种,大多为中国特有种。油杉属植物许多种类的形态特征差异不明显,通过列表详细比较了每一种油杉属植物的形态特征差异,并编制了油杉属分种检索表,以利于对油杉属各种及其变种的识别。     

燕山山脉野生欧李花粉的形态特征

通过对燕山山脉野生欧李群体中34株实生和嫁接类型花粉形态特征进行电镜扫描观测,研究野生欧李资源演化进化以及抱粉学特征.结果表明,燕山山脉的欧李花粉形状大体划分为长球形或超长球形,极面观为三裂圆形,具三孔沟,按NPC系统分类属于N_3P_4C_5型.花粉外壁纹饰呈穿孔纹饰、条纹-穿孔纹饰和条纹状纹饰3种类型.欧李不同株系...     

木瓜属植物的花粉形态及品种分类

对木瓜属19个品种的花粉亚显微形态进行扫描电镜观察.结果表明:其花粉属于N3P4G3型,为辐射对称的长球形至超长球形,大小为极轴长48.64～39.95 μm、赤道轴长25.28～20.97 μm,外壁纹饰为条纹状或皱波状纹饰,具覆盖层穿孔.花粉亚显微形态对于木瓜属品种分类具有很大价值,根据花粉形态编制品种分类检索表.聚类分析结果表明,贴梗海棠、日本木瓜和傲大贴梗海棠的亲缘关系最近,而木瓜与其他种类的亲缘关系疏远,这与本属的经典分类结果一致.     

蝴蝶兰的形态特征及栽培方法

蝴蝶兰,兰科多年生草本,主要分布在我国的台湾省,是观赏价值和经济价值很高的盆栽花卉。蝴蝶兰一般在早春开花,且枝叶繁茂,花朵硕大,颜色艳丽,形态独特,花期长久,结构精巧、奇特,深受广大花卉栽培的欢迎和喜爱,是目前室内绿化、美化的新型观赏花卉。     

5种落叶松种子形态特征及其区分方法的初步研究

应用XTB—01型解剖镜(10×)对日本落叶松、兴安落叶松、长白落叶松、华北落叶松和新疆落叶松5个树种种子的8个形态特征的观察,可以将它们区分开来。并提出了应用多元一次方程组的方法,确定混杂种子中各种落叶松种子的比例。经过对辽宁省有关市县种子检验员和种子收购员稍加培训后,对这些落叶松及人工配制的混合种样的检验和统计分析,证明该研究结果是可行的。     

影响省藤弹性的参数和弹性方程式的确定

本文评估了省藤结构(基本薄壁组织和微管束分布)、物理特征(微纤维角度、结晶度和非晶区)和细胞壁化学成分(纤维素、半纤维素和木质素)对压缩应力的影响,以确定一个能测定省藤弹性的数学模式。进行了图象分析,碘染色,x光衍射技术和标准化学分析。最后,用热机械分析仪测定了压缩应力。回归方程表明,在不同参数中,基本薄壁组织比例、微纤维角度、非晶区大小和半纤维含量与压缩应力呈正相关。多元回归的数学方程为Y=0.012x₂-0.0001x₁+0.016x₃+0.017x₄-1.861,其中Y=压缩应力,x₂=微纤维角度,x₁=基本薄壁组织,x₃=非晶区,x₄=半纤维含量。在这些参数中,当P=0.050,半纤维含量的影响最大。     

Effects of the interaction between drought and shade on water relations, gas exchange and morphological traits in cork oak (Quercus suber L.) seedlings

The combined effect of drought and light on different physiological and biochemical traits was assessed in cork oak (Quercus suber L.) seedlings grown under two levels of light availability and submitted to a long-standing drought. Watering was withdrawn after germination and seedlings were allowed to dry to a water content of ca. 50% of field capacity. At this point, water-stressed seedlings were grown under moderate drought and two light regimes: high light (HL—50%) and low light (LL—2%). Soil water in control plants was kept close to field capacity (90–100%) for both light environments. Water-relations parameters derived from P–V curves, gas exchange and water status at predawn (Ψ_pd) were evaluated at twice during the experiment. Nitrogen and chlorophyll contents were determined in the same leaves used for the gas exchange measurements. In addition, maximum rate of carboxylation (V_cmax) and electronic transport (J_max) were derived from A–C_i curves in well-watered seedlings.

The variation on moisture availability during the experiment was the same under both light environments. In control plants, Ψ_pd was over −0.3 MPa at the two harvests, while stressed seedlings decreased to −0.9 MPa, with no differences between light treatments. Water stress decreased osmotic potentials at full (Ψπ₁₀₀) and zero turgor (Ψπ₀). The regressions between both potentials and Ψ_pd showed a higher intercept in shade grown seedlings. This fact will point out the higher osmoregulation capacity in sun seedlings whatever water availability.

Nitrogen investment on a per leaf mass (N_mass), chlorophyll content (Chl_mass) and SLA tended to show a typical pattern of sun-shade acclimation. Thus, the three parameters increased with shade. Only for N_mass there was a significant effect of watering, since water stress increased N_mass.

LL plants showed a lower photosynthetic capacity in terms of maximum net photosynthesis at saturating light (A_max), which was related to a decrease in V_cmax and J_max. Both parameters varied with specific leaf area (SLA) in a similar way. The low-light environment brought about a higher nitrogen investment in chlorophyll, while under high-light environment the investment was higher in carboxylation (V_cmax) and electronic transport (F_max).

Stomatal conductance to water vapour (g_wv) and A_max were lower in low-light seedlings independently of watering. In addition, there was a trend to keep higher intrinsic water use efficiency (IWUE) under high light environment. The increase of IWUE under water stress was higher in HL seedlings. This was as consequence of the steeper decline in g_wv as Ψ_pd decreased. The decrease of A_max with Ψ_pd occurred in a similar way in LL and HL seedlings. Thus, the HL seedlings tended to sustain a higher ability to increase IWUE than LL seedlings when they were submitted to the same water stress.     

盈江省藤苗木生长对肥料种类和施用量的响应

采用L₉(3⁴)正交设计对造林11和15个月的盈江省藤分别开展施肥试验,施肥后1个月测定苗木的生长指标,包括地径、冠幅、叶片数、叶片长及新叶数,研究不同肥料种类(N:P:K为11:8:6的复合肥、N:P:K为20:5:20的复合肥、过磷酸钙)、施肥量(25 g/株、50 g/株、75 g/株)以及是否施用尿素对苗木生长的影响。结果表明:肥料施用量、是否施尿素以及两者的组合是影响苗木生长的主导因子;不同肥料种类及不同的施用量对苗木各生长指标的影响不同;不同肥料种类对冠幅、叶片长和新叶数具有极显著或显著的影响(P_冠幅=0.017<0.05,P_叶片长=0.004<0.01,P_新叶数=0.038<0.05),不同肥料施肥量则极显著影响地径、冠幅和叶片长(P=0.000<0.01),尿素不同施用量显著影响叶的生长。总体而言,过磷酸钙有利于盈江省藤叶的生长,N:P:K配比为11:8:6的复合肥可增加苗木叶片数和新叶数,尿素对苗木生长具有负效应,不宜施尿素。     

微生物菌肥与化学肥料配施对盈江省藤生长的影响

为了解不同肥料种类及其施肥量对盈江省藤生长的影响,采用L₉(3⁴)正交试验设计对其2年生幼林进行连续3年的微生物菌肥与复合肥和磷肥配施试验。结果表明,3年中不同因素的各水平组合间苗木的地径、株高、叶片数和冠幅均呈现极显著的差异(P<0.01)。施用复合肥和磷肥总体呈现显著(P<0.05)或极显著(P<0.01)地抑制盈江省藤生长的现象。不同肥料配施试验组合的地径、株高和叶片数均大于对照的相应指标。试验期间,单施微生物菌肥0.3~0.6 g/株即可满足盈江省藤生长的需求。     

Growth responses, physiology and decay associated with pruning plantation-grown Eucalyptus globulus Labill. and E. nitens (Deane and Maiden) Maiden

Detailed studies have been undertaken to define pruning regimes for Eucalyptus nitens, but little is known of E. globulus responses to pruning although this is a more commonly planted species. This paper describes experiments that aimed to identify (a) levels of pruning that reduce E. globulus growth, (b) physiological processes contributing to those growth responses, (c) the incidence of decay and factors influencing decay incidence following pruning of E. globulus, and (d) comparative responses of E. nitens and E. globulus to live branch pruning. Results of a field experiment indicated that removal of between 30 and 50% of the crown length was appropriate for E. globulus plantations verging on canopy closure. The significant reduction in height growth associated with removal of 50 or 70% of crown length suggested pruning should remain below 50% of crown length if reduced stem growth of pruned trees was to be avoided. Stem volume was only significantly reduced over the period of the experiment by 70% pruning, but it was estimated that standing volume following removal of 50% of crown length would be reduced by 82 m³ ha⁻¹ over a 20-year rotation if there were no other silvicultural interventions. The growth responses observed were probably related to large reductions in leaf area following 50 or 70% removal of crown length. Trees responded to pruning by changing patterns of biomass partitioning to favour stem growth at the expense of branch growth. A glasshouse study determined that light-saturated net CO₂ uptake (A_max) increased following pruning. E. nitens seedlings had both a higher baseline A_max and higher A_max following pruning than did E. globulus, which could partially explain the greater effect of pruning on E. globulus growth than has been observed for E. nitens in other studies. This result, as well as apparently different patterns of foliage distribution through the crowns of E. globulus and E. nitens, suggested that models of pruning responses need to be parameterised for both species. In addition, a more conservative pruning regime may be appropriate for E. globulus than E. nitens. Pruning increased the frequency of branch traces with decay infection, and there was a trend towards increasing decay outbreaks with increasing pruning severity. Decay outbreaks were more likely to occur following pruning of high angle or larger diameter branches.     

中国鹅掌楸与北美鹅掌楸种间杂交的胚胎学研究*

应用控制授粉、常规石蜡切片技术研究了中国鹅掌楸与北美鹅掌楸种间杂交后的胚胎发育过程。结果表明：（１）控制授粉后花粉正常萌发，并有较多的花粉管进入柱头，但花粉管在花柱内生长缓慢甚至解体；（２）花粉萌发６ｄ后花粉管经花柱沟、珠孔塞和珠心冠原组织进入胚囊进行珠孔受精，２０ｄ时游离核胚乳细胞化，发育形成２～４个细胞厚的狭长组织，３５ｄ后可观察到球形胚；（３）随着胚和胚乳的发育，珠被发育形成种皮。授粉时，胚珠具２层珠被，外、内珠被均由外表皮、中层和内表皮组成；胚与胚乳发育期间，珠被各层发生了一系列的变化，最终种皮由外珠被的外表皮细胞形成的膜层和中层细胞形成的气室以及内、外珠被内表皮细胞形成的硬化层组成；（４）受精时成熟胚囊及到达珠孔的花粉管的数目较少，受精频率较低；（５）受精过程基本正常，但胚和胚乳发育不协调，导致胚在发育早期败育，很难观察到后期胚的发生。     

Variation analysis of seed and seedling traits of cross combination progenies in Populus

Twenty-five species and hybrids in Populus were used as parents, and 26 cross combinations, including more than 5 000 seedlings, were obtained by artificial cross breeding. The length of infructescence, number of seeds per infructescence, thousand-seed weight, germination rate of seeds among these cross combinations were tested. The results indicated that the cross combinational effects were significant for these traits, and demonstrated that the length of infructescence, thousand-seed weight were positively affected by female parent. In addition, seedling height, diameter above ground, diameter at breast height (DBH) of 17 cross combination progenies were investigated. The analysis of mean and standard deviation of these three traits showed that seedling height, diameter above ground, DBH had extensive variation among combinations and individuals within combination. Variance analysis and estimate of heritability indicated that the three traits had wide variation and were controlled by heredity. It was feasible to select superior cross combinations and seedlings. Further more, the result of multiple comparison showed that P. deltoides ‘Lux’ × P. deltoides ‘D324’, P. ussuriensis cl. ‘U4’ × P. deltoides ‘T66’, P. ussuriensis cl. ‘U4’ × P. deltoides ‘T26’, P. deltoides ‘Lux’ × P. ussuriensis cl. ‘U3’, (P. tomentosa × P. bolleana) × (P. alba × P. glandulosa), (P. alba × P. tomentosa) × (P. alba × P. glandulosa), and (P. alba × P. glandulosa ‘No. 2’) × P. tomentosa ‘Lumao 50’ were superior cross combinations with higher growth rate. Finally, 123 elite seedlings were selected for further test. [Supported by the Doctoral Foundation of Ministry of Education (Grant No. 200220022004) and the National “863” Project (Grant No. 2002AA241071)]