Influence of male cones on early season vegetative growth of Pinus contorta trees

On average, branches of Pinus contorta Dougl. bearing male cones had 35 fewer needle pairs than equivalent vegetative branches, and significantly fewer differentiated primordia (i.e., male cones + needle pairs + sterile cataphylls). It was estimated that the formation of male cones results in a 27-50% reduction in the number of needles per male cone-bearing branch. In early spring, branches bearing male cones had on average 23% (0.44 g) more dry weight than vegetative branches. On average, 95% of the dry weight of male cone-bearing branches was allocated to the terminal shoot (54% of which was male cones) and 5% to the lateral shoots. By comparison, vegetative branches allocated 85% of their total dry weight to the terminal shoot and 15% to the lateral shoots. These findings suggest that male cones may reduce the photosynthetic potential of the trees which bear them.     

Effects of gibberellin A(4 + 7) and bark-ringing on cone initiation in mature Picea sitchensis grafts

Large numbers of cones (strobili) were induced in a 10-year-old plot of mature grafts of Picea sitchensis (Bong.) Carr. All trees injected with 20 mg GA(4 + 7) in June initiated female and male cones in the same year. This treatment increased the number of female cones per plant 12-fold above the controls, more than doubling the percentage of cones that were female. Complete bark-ringing (done in May of the previous year) showed an additive effect with GA on the number of female cones formed, but a negative interaction on the number of male cones induced. Ringing promoted male cone production most when used alone. Treatments, singly or combined, also increased the proportion of cones that were lateral, compared with the preponderance of terminal male cones in the controls. The effects were apparently not directly associated with alterations in vegetative vigor, although these occurred causing a reduction in the proportion of buds containing vegetative shoots the following year. The clones differed in most characteristics, but both sparse and prolific clones were induced to reproductive activity. Viable seed yields per tree, and notional production from seed-orchards were enhanced almost 10-fold by GA injection, and about 4-fold by bark-ringing and GA + bark-ringing.     

日本落叶松种子园优良家系球花分布规律及花量调查

对日本落叶松种子园优良家系雌雄球花数量及在树冠上的分布规律进行调查分析。结果表明:日本落叶松雄球花在树冠垂直方向上分布差异极显著,下层和中层的数量显著多于上层,所占比例为83.39%,水平方向上南面的雄球花多于其他方向;雌球花在树冠不同冠层的分布无显著差异,中、上层的雌球花数量比下层多,东、南方向多于西、北方向;雄球花多着生在2,3 a生枝上,雌球花多着生在3,4 a生枝上,1 a生枝条上无花;不同无性系间雌雄球花数量差异显著,356号无性系的雌雄球花数量均为最多。     

树冠修剪和切根处理对红松母树雌雄球花分化的影响

以红松种子园中的生长形状相对一致的嫁接母树为试验材料,研究不同树冠修剪和切根方法对母树雌雄球花分化数量的影响。结果表明,不同处理均对母树雌雄球花分化数量有显著的促进作用,其中:剪去树冠第一层轮枝和顶梢部分,在第二层轮枝中选留3个生长健壮且分布均匀的侧枝,其余侧枝全部剪除的处理方法,对雌球花分化数量的增加作用最为明显,差异达到极显著水平;切断试验母树3/4环形沟中的根系和试验母树环形沟中全部根系的处理方法,对雌雄球花分化数量的增加作用最为明显,差异达到极显著水平。     

Applying a universal scaling model to vascular allometry in a single-stemmed, monopodially branching deciduous tree (Attim's model)

West, Brown and Enquist (1999a) modeled vascular plants as a continuously branching hierarchical network of connected links (basic structural units) that ends in a terminal unit, the leaf petiole, at the highest link order (WBE model). We applied the WBE model to study architecture and scaling between links of the water transport system from lateral roots to leafy lateral branches and petioles in Populus deltoides Bartr. ex Marsh. trees growing in an agroforestry system (open-grown trees) and in a dense plantation (stand-grown trees). The architecture of P. deltoides violates two WBE model assumptions: (1) the radii of links formed in a branching point are unequal; and (2) there is no terminal unit situated at the end of a hierarchical network, rather, petioles are situated at any link order greater than 1. Link cross sections were taken at various link orders and morphological levels in roots and shoots of open-grown trees and shoots of stand-grown trees. Scaling of link radii was area-preserving. From roots to branches, vessel diameters were scaled with link order in accordance with a 1/6-power, as predicted by the WBE model indicating general vessel tapering. However, analysis of the data at the morphological level showed that vessel radius decreased intermittently with morphological level rather than continuously between successive link orders. Estimation of total water conductive area in a link is based on conducting area and petiole radius in the WBE model. The estimation failed in P. deltoides, probably because petioles are not a terminal unit. Biomass of stand-grown trees scaled with stem basal radius according to the 3/8-power predicted by the WBE model. Thus, the WBE model adequately described vascular allometry and biomass at the whole-tree level in P. deltoides despite violation of Assumption 1, but failed in predictions where the leaf petiole was used as a terminal unit.     

促进三台核桃中幼树生长结实技术措施研究

为了探寻能促进云南三台核桃中幼树生长结实的技术措施,从而为云南核桃的提质增效提供理论依据,以树龄为10~15 a的三台核桃中幼树为研究对象,采用修剪、螺旋环剥、花前灌水这3种技术处理进行了为期2年的试验研究,调查和综合比较分析了不同处理的新梢发枝力、果枝率、新梢生长量、单株产量。结果表明:螺旋环剥处理,能增加母枝抽发的新梢数量,但对新梢的营养生长却有一定的抑制作用,能使其果枝率和单株产量均有提高,其平均单株结果数可达508.3个,增产效果明显;修剪处理,增强了中幼树的发枝力,增加了母枝抽发的新梢数量,增产效果也较明显;花前灌水处理,促进了新梢的长度生长和粗度生长,促进了其营养生长,对其果枝率和单株结果数均一定的促进作用,但增产效果不很显著。     

Control of shoot elongation in ponderosa pine: relative roles of apical and axillary meristems

Buds of ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) from which the shoot apical meristems had been surgically removed elongated normally but did not form new terminal buds. Shoot, stem unit and needle growth were similar to those of controls. Removal of needle fascicles from buds starting to elongate inhibited growth, whether or not the shoot apical meristem had been removed. The length of completely defoliated shoots increased by 8.3%, the length of shoots defoliated on the upper half increased by 29.6%, and the length of those defoliated on the lower half increased by 44.9%. The length of controls increased by 137.4% during the same period. On partially defoliated shoots, defoliated stem units elongated less than undefoliated ones. Shoots developing from buds enclosed in light-proof, aluminum-foil bags elongated normally but apparently lacked chlorophyll. Increases in dry weight were significantly correlated with number of stem units (r(2) = 0.53). Results suggest that shoot elongation is controlled endogenously. This control may be mediated by IAA outputs from axillary meristems proportional to meristem number, and the importation of carbohydrates, proportional to the output of IAA.     

罗田垂枝杉不同材料扦插试验研究

为探索罗田垂枝杉的无性繁殖,以大树侧枝和基部萌条及采穗圃穗条为试验材料进行扦插,分析不同材料、不同系号及不同激素处理生根差异。结果表明:20 a以上的大树Ⅱ级侧枝的扦插生根率较低,为48.11%,而Ⅰ级侧枝的扦插生根率可达65%以上;萌条扦插生根率(88.86%)要远高于优树侧枝扦插生根率(48.01%),两者差异达到极显著水平(p0.01),黄化未木质化穗条扦插生根率仅为6.67%,远低于其他萌条86.94%~91.67%的生根水平,不同系号间萌条生根率从51.57%~98.77%不等;激素处理的采穗圃穗条生根率都在91.57%以上,粉剂1处理后生根数量最多,与其余三种处理差异达到显著水平。可见侧枝扦插要显著差于萌条扦插,而激素处理可以有效提高扦插生根率。     

不同类型薄壳山核桃苗木栽植效果研究

以淮安地区种植园的1年生和泰州地区种植园的2年生‘波尼’薄壳山核桃苗为试材,研究裸根苗、土球苗、无纺布容器苗等3种不同类型薄壳山核桃苗栽植后生长发育的差异。结果表明:3种类型苗木栽植后新梢和根系生长差异较为显著。两处均以无纺布容器苗成活率最高,达到100%;新梢生长量最大,1年生和2年生苗木的生长量分别为110.77 cm和53.44 cm;根系也最为发达。土球苗次之,裸根苗的新梢、根系生长量最小。分析表明,在江苏淮安和泰州这两个地区,无纺布容器苗的成活率、平均新梢生长量、分枝数、总的新梢生长量、主根长度、粗度、侧根数量等均优于土球苗和裸根苗的。此外,3种类型苗木栽植后,2年生苗木的地上、地下部分生长均优于1年生苗木的。     

Seasonal shoot and needle growth of loblolly pine responds to thinning, fertilization, and crown position

The impacts of thinning, fertilization and crown position on seasonal growth of current-year shoots and foliage were studied in a 13-year-old loblolly pine (Pinus taeda L.) plantation in the sixth post-treatment year (1994). Length of new flushes, and their needle length, leaf area, and oven-dry weight were measured in the upper and lower crown from March through November. Total shoot length was the cumulative length of all flushes on a given shoot and total leaf area per shoot was the sum of leaf areas of the flushes.

By the end of June, first-flush foliage reached 70% of the November needle length (14.3 cm) and 65% of the final leaf area (15.0 cm²). Cumulative shoot length of first- and second-flush shoots achieved 95% of the annual length (30.3 cm), whereas total leaf area per shoot was 55% of the final value (75.3 dm²). Fertilization consistently stimulated fascicle needle length, dry weight, and leaf area in the upper crown. Mean leaf area of upper-crown shoots was increased by 64% six years after fertilization. A significant thinning effect was found to decrease mean leaf area per shoot in the crown. For most of the growing season, the thinned-fertilized trees produced substantially more leaf area per shoot throughout the crown than the thinned-nonfertilized trees. These thinned-fertilized trees also had greater needle length and dry weight, longer first flush shoots, and more leaf area per flush than trees in the thinned-nonfertilized plots. Needle length and leaf area of first flush shoots between April and July were linearly related to previous-month canopy air temperature (T_a). Total shoot length strongly depended on vertical light gradient (PPFD) within the canopy, whereas shoot leaf area was a function of both PPFD and T_a. Thus, trees produced larger and heavier fascicles, more and longer flush shoots, and more leaf area per shoot in the upper crown than the lower crown. We conclude that thinning, fertilization, and crown position regulate annual leaf area production of current-year shoots largely by affecting the expansion of first flush shoots and their foliage during the first half of the growing season.     

Growth and reproduction in <Emphasis Type="Italic">Pinus sibirica</Emphasis> ecotypes from Western Siberia in a common garden experiment

Experimental studies of forest trees’ intraspecies variations in reproduction and reproductive allocation are scarce. Such studies are relevant for the Siberian stone pine (Pinus sibirica Du Tour) because of the high value of its seeds and wood. To reveal growth and reproductive variations among Siberian stone pine ecotypes in relation to the climate of the provenances, we examined their growth height, crown diameter, stem volume, number of female cones, and male shoots, at different ages, in the clonal common garden experiment established in 1996 in Russia. Scions were obtained from 11 to 19 randomly selected 100–170-year old trees in each of four natural stands located on the latitudinal transect on the West Siberian plain. They were grafted onto local 4 year old Siberian stone pine seedlings and grown in a common garden experiment comprising nine plots near the southern margin of the species’ natural range. Growth traits were affected by climatic conditions in the provenances: generally, a warmer climate was associated with more rapid growth. Variation among the ecotypes at the graft age of 12 years was not large; however, it significantly increased by the age of 19. The relationship was ambiguous between reproductive traits and the climate of the provenances. The proportion of female, male and bisexual clones varied among years in all ecotypes. Most of the clones had only female cones; male clones were less common. The southern ecotype showed rapid growth and formed the lowest number of male shoots and female cones. The northern ecotype showed the weakest growth and moderate cone bearing, along with abundant male flowering. The intermediate ecotypes had a moderate growth and the highest numbers of cones, along with moderate numbers of male shoots. These results demonstrate the fundamental differences in the patterns and nature of variation in growth and reproductive traits.     

Changes in shoot allometry with increasing tree height in a tropical canopy species,Elateriospermum tapos

Allometry of shoot extension units (hereafter termed "current shoots") was analyzed in a Malaysian canopy species, Elateriospermum tapos Bl. (Euphorbiaceae). Changes in current shoot allometry with increasing tree height were related to growth and maintenance of tree crowns. Total biomass, biomass allocation ratio of non-photosynthetic to photosynthetic organs, and wood density of current shoots were unrelated to tree height. However, shoot structure changed with tree height. Compared with short trees, tall trees produced current shoots of the same mass but with thicker and shorter stems. Current shoots with thin and long stems enhanced height growth in short trees, whereas in tall trees, thick and short current shoots may reduce mechanical and hydraulic stresses. Furthermore, compared with short trees, tall trees produced current shoots with more leaves of lower dry mass, smaller area, and smaller specific leaf area (SLA). Short trees adapted to low light flux density by reducing mutual shading with large leaves having a large SLA. In contrast, tall trees reduced mutual shading within a shoot by producing more small leaves in distal than in proximal parts of the shoot stem. The production of a large number of small leaves promoted light penetration into the dense crowns of tall trees. All of these characteristics suggest that the change in current shoot structure with increasing tree height is adaptive in E. tapos, enabling short trees to maximize height growth and tall trees to maximize light capture.     

油松侧枝的节间特征及其变异规律

【目的】为阐明油松侧枝的节间特征及其变异规律,了解当年生节间枝条和针叶的异速生长关系,揭示侧枝空间构型、活力和光合产物分配的主要影响因子。【方法】本研究在35 a生油松林内选取了5株标准木的标准枝,通过枝条解析截取了372个节间,采用统计分析和模型模拟等方法对相关问题进行了研究。【结果】结果表明:油松枝条多分为3级,近90%的节间分布在2级和3级枝,直径生长周期为1~4 a、具有针叶着生和光合功能的节间占节间总数的83%;节间直径和长度均随枝级增加而显著下降,均随节间生长周期(或形成时间)的增加而显著增加,后者在枝级间及枝级内的变异均远高于前者,后者受枝级和着生位置光照环境的影响明显高于前者。全枝70%以上的枝条生物量分布在1级枝节间,80%以上的针叶分布在2级和3级枝节间;1级和2级枝的生物量以枝条为主,3级枝以针叶为主。直径生长周期为1~3 a的节间生物量以叶为主,4 a的以枝条为主,4 a以上的以完全以枝条为主。当年生节间的不同特征变量间均成显著的异速生长关系,而非成比例变化。【结论】节间是侧枝的基本单元,其数量、质量、生长发育及其在不同枝级和形成时间的变异,以及其主要构件的异速生长关系是影响侧枝空间构型、活力和光合产物分配的主要因子。     

银杏雄性优良单株选择的初步研究

通过对11个与银杏良种桂G86-1花期接近或相遇的雄株2年生长枝上的短枝间距、花芽率、每短枝上雄花数及雄花穗长、粗,出粉率等各项性状的分析,发现B号雄性单株的散粉期与桂G86-1花期基本相遇,且散粉期长,花芽率高,出粉量大,每单位长枝上雄花数多,是桂G86-1的最适宜授粉树。     

银杏枝条营养贮藏蛋白质的组分及动态变化

采用SDS-聚丙烯酰胺凝胶电泳技术和电子显微镜技术,对银杏枝条营养贮藏蛋白质组分及其动态变化规律进行研究.结果表明:银杏营养贮藏蛋白质主要存在于枝条的树皮和木质部中;当年生枝条含量高于2年生枝条,树皮的含量高于木质部;枝条中营养贮藏蛋白质组分主要是分子质量为36 ku和32 ku的蛋白质;银杏营养贮藏蛋白质的动态变化分为积累和降解2个阶段,5月中旬新叶形成后即开始积累,12月份达到最高,翌年春季降解满足芽的萌发,至4月上旬逐渐消失.     

Lateral female strobili production in a Japanese red pine (Pinus densiflora Sieb. et Zucc.) clone by exogenous cytokinin application

Application ofN ⁶-benzylaminopurine (BAP) and gibberellin (GA₃) to a grafted Japanese red pine (Pinus densiflora Sieb. et Zucc.) clone promoted flowering. BAP (250 mg/l) was sprayed five times to the top of branches in July or September 1992. GA₃ (100 or 500 mg/l) was applied five times to the whole plants by spray treatment during the above period, or GA₃ solution of the same concentration was injected once into a small incision made in the main stem of clone trees at the beginning of July or the middle of September 1992. In May 1993, no apical female strobili were observed at the top of the new shoots in any treatment. However, lateral female and bisexual strobili were produced in the lower part of new shoots by BAP application in September, regardless of GA₃ application. BAP applied in September without GA₃ application was sufficient to produce lateral female and bisexual strobili. In such treatment, production of female and bisexual strobili was 47 and 25, and they occurred in 16 out of 68 new shoots, 11 out of 15 treated branches and 5 out of 5 treated trees. The average number of female and bisexual strobili per new shoot was 1.06. BAP treatment either in July or in September significantly decreased (p<0.05) the production of male strobili. These results indicate that BAP application induces the development of lateral female strobili in Japanese red pine when applied during the period of floral differentiation. A part of this paper was presented at the 105th annual meeting of the Japanese Forestry Society.     

结果期甜柿新梢冬季留桩短截修剪效应调查

针对生产中对甜柿结果期新梢冬季留桩短截修剪不规范的现象进行调查,结果表明:新梢冬季修剪,无论留桩长、短和桩的茎粗、细,翌年春季与对照的不留桩短截相比较,均表现分枝数较少,营养枝多,结果枝和花朵数少。冬季留桩短截修剪措施明显影响甜柿的正常结果。     

Light interception and partitioning between shoots in apple cultivars influenced by training

The effect of two training systems (Central Leader with branch pruning versus Centrifugal Training with minimal pruning, i.e., removal of fruiting laterals only) on canopy structure and light interception was analyzed in three architecturally contrasting apple (Malus domestica Borkh.) cultivars: 'Scarletspur Delicious' (Type II); 'Golden Delicious' (Type III); and 'Granny Smith' (Type IV). Trees were 3D-digitized at the shoot scale at the 2004 and 2005 harvests. Shoots were separated according to length (short versus long) and type (fruiting versus vegetative). Leaf area density (LAD) and its relative variance (xi), total leaf area (TLA) and crown volume (V) varied consistently with cultivar. 'Scarletspur Delicious' had higher LAD and xi and lower TLA and V compared with the other cultivars with more open canopies. At the whole-tree scale, training had no effect on structure and light interception parameters (silhouette to total area ratio, STAR; projected leaf area, PLA). At the shoot scale, Centrifugal Training increased STAR values compared with Central Leader. In both training systems, vegetative shoots had higher STAR values than fruiting shoots. However, vegetative and fruiting shoots had similar TLA and PLA in Centrifugal Trained trees, whereas vegetative shoots had higher TLA and PLA than fruiting shoots in Central Leader trees. This unbalanced distribution of leaf area and light interception between shoot types in Central Leader trees partly resulted from the high proportion of long vegetative shoots that developed from latent buds. These shoots developed in the interior shaded zone of the canopy and therefore had low STAR and PLA. In conclusion, training may greatly affect the development and spatial positioning of shoots, which in turn significantly affects light interception by fruiting shoots.     

Effects of exogenous gibberellin and auxin on shoot elongation and vegetative bud development in seedlings of Pinus sylvestris and Picea glauca

The hormonal control of stem unit (foliar appendage and axillary structure, if present, plus subtending internode) number and length was investigated in shoots of Scots pine (Pinus sylvestris L.) and white spruce (Picea glauca (Moench) Voss). Seedlings were treated with six gibberellins (GA1, GA3, GA4, GA5, GA9 and GA20) and two auxins (indole-3-acetic acid (IAA) and naphthaleneacetic acid (NAA)) when either neoformed growth was occurring or the terminal vegetative bud was developing. Hormones were applied by drenching the shoot tip, injecting the stem or spraying the foliage. Combined results for all three application methods indicated that shoot elongation in first-year seedlings (i.e., neoformed growth) was promoted in both species by GA1, GA3, GA4 and, less obviously, by GA9. This promotion was attributable to an increase in length, rather than number, of stem units. However, the number of stem units formed during terminal bud development, as reflected in the number of needles (white spruce) or cataphylls (Scots pine) present on the shoot resulting from the terminal bud, was stimulated by GA1, GA3 and GA4 in both species and by GA9 in Scots pine. The GA-induced increase in the number of preformed stem units was associated with increased bud width in white spruce and increased bud length and resulting shoot length in Scots pine. In contrast, application of IAA or NAA either did not affect or inhibited both neoformed growth and terminal bud stem unit number, depending on the application method and concentration. We conclude that, in the Pinaceae, (1) GA stimulates the activity of both the subapical meristem during neoformed growth and the apical meristem during vegetative bud development, and (2) the early non-hydroxylation pathway, via GA9, is the major route of GA biosynthesis. The role of auxin in the control of stem unit number and length remains to be resolved.     

The growth of shoots and lateral roots of Quercus robur L. seedlings following simulated undercutting

The effect of cutting the tap root on shoot growth and development of lateral roots was observed in seedling Quercus robur L. growing in PVC tubes containing peat and perlite. Cutting the tap root had little effect on shoot height and leaf number although some treatments caused a significant but slight reduction in shoot dry weight and number of branches. Total root dry weight was similar in control and treated plants but distributed differently between the types of root present. The tap root always formed the largest part of the total root dry weight. In control plants most lateral root dry weight was in roots < 1 mm diameter whereas in treated plants most dry weight was in roots > 1 mm diameter. Development of the root system following root cutting was similar for all treatments: new long laterals > 1 mm diameter with relatively few branches, that formed replacement tap roots, developed near the cut end of the original tap root. Fine laterals (< 1 mm diameter) near the root collar continued to grow forming highly branched systems.