1年生泡桐不同部位顶芽内源激素的动态变化

在河南省郑州市以1年生毛白33泡桐为试验材料,利用间接酶联免疫吸附测定法(ELISA)测定梢枝顶芽、上部侧枝、中部侧枝和下部侧枝的顶芽内源激素含量动态变化。结果表明:1)梢枝顶芽、上部侧枝顶芽、中部侧枝顶芽及下部侧枝顶芽IAA的变化趋势一致,变化趋势为"降低-升高-降低",只是上部侧枝顶芽IAA升高后降低的趋势可能会推迟;2)梢枝顶芽、上部侧枝顶芽和下部侧枝顶芽GA3含量变化趋势基本相同,均呈现出"上升-下降-上升-下降"的"双峰"形;而中部侧枝顶芽GA3含量呈现出"下降-上升-下降"的趋势;3)不同部位顶芽ABA含量均是先升高,之后下降,最后在较低水平上趋于稳定状态;4)泡桐不同部位顶芽ZR含量随时间的变化呈现出不同趋势,但总体呈下降趋势,且不同部位顶芽间存在着竞争关系及抑制作用;5)8月15日—9月15日,IAA,GA3,ZR,ABA及(IAA+GA3+ZR)/ABA比值均呈下降趋势,表明促进生长类激素与导入休眠类激素均较低,泡桐顶芽和其他邻近组织相比其竞争优势在逐渐丧失,内源激素的动态平衡被打破。本研究结果初步探明顶芽死亡与内源激素的关联性,为进一步探讨泡桐死亡机理奠定基础。     

Physiological, environmental and genetic variation in apical dominance as determined by decapitation in Triplochiton scleroxylon

Patterns of lateral shoot growth following decapitation in 1-meter tall, rooted Triplochiton scleroxylon K. Schum. cuttings varied with clone and in response to a range of environmental conditions and growth regulator treatments. Two phases of bud activity were identified, the Sprouting Phase, in which many buds were released from correlative inhibition, and the Dominance Phase (starting 3-4 weeks after decapitation) in which uppermost laterals began to dominate and suppress growth, and sometimes cause apical abscission of lower lateral shoots. Except in non-erect plants, the most distal lateral to elongate became the new leading shoot. During the Sprouting Phase, the proportion of active buds was increased by removing leaves from the upper part of the stem, and by reducing the photoperiod from 13-15 h to 11 h, particularly at 20 degrees C rather than 25 degrees C. Conversely, the proportion of sprouting buds was decreased by injecting plant stems with NAA (250 microg/plant). During the Dominance Phase, suppression of lateral shoot growth was hastened by stem injection with GA(3) (200 microg/plant), especially when applied to the uppermost shoot at the end of the Sprouting Phase. Reimposition of dominance was delayed, however, by (1) high rates of N:P:K fertilization, (2) low temperature (20 versus 25 degrees C) under relatively long days (13 and 15 h), (3) low photon flux density (160 micromol m(-2) s(-1)) and (4) severe defoliation. Plant orientation had no effect on bud activity of decapitated plants, but affected the relative vigor and orientation of new lateral shoots. High temperature (25 versus 20 degrees C) and injection with GA(3) increased the erectness of newly developing lateral shoots.     

Influence of female cones on the vegetative growth of Pinus contorta trees

Branches of Pinus contorta Dougl. bearing two-year-old female cones initiated fewer lateral buds than vegetative branches. However, the number of lateral shoots that differentiated and grew was not reduced on female cone-bearing branches. Neither the number nor the weight of female cones influenced the length of the terminal shoot. The total length of all lateral shoots was positively associated with the weight of two-year-old female cones. Branch units with two-year-old female cones produced significantly more total dry weight in the current year than vegetative branch units. There was, however, no significant reduction in the dry weight of terminal and lateral shoots. Branches bearing female cones allocated between 17 and 45% of the current year's dry weight to two-year-old cones and between 1 and 5% was allocated to one-year-old female cones. Female cones therefore apparently do not reduce the photosynthetic potential of trees. The influence of female cones compared with male cones on the growth of trees is discussed.     

Lateral bud outgrowth on decapitated shoots of low-pruned mulberry (Morus alba L.)

After decapitation, lateral shoot growth of mulberry coppice (Morus alba L. cv. Shin-ichinose) from 10-year-old stumps had an extremely acrotonic form compared with that of intact one-year-old stems of trees during the spring. When one dominant shoot from each stump was decapitated, only a few upper lateral buds grew out and elongated. Defoliation of the decapitated shoots resulted in an increase in the number of shoots sprouting and a decrease in the rate of elongation of the laterals. Further enhancement of laterals on decapitated dominant shoots resulted from the removal of competing intact coppice shoots from the stumps. 1-Naphthaleneacetic acid (NAA) applied as a spray reduced the number of lateral buds sprouting from both defoliated, decapitated erect shoots and intact horizontally trained shoots. The results suggest that management of mulberry coppice could increase the supply of leaves for commercial silk production.     

Inhibition of orthotropic replacement shoots with auxin treatment on decapitated hoop pine,Araucaria cunninghamii,for seed orchard management

Seed production in orchards of Araucaria cunninghamii involves grafting plagiotropic scions (using a terminal-side graft) which exhibit a lateral growth habit onto decapitated stock trees. Decapitation effectively releases buds in the leaf axils of the stock plant from apical dominance and orthotropic replacement shoots develop rapidly. To prevent suppression of the grafted scion, frequent removal of orthotropic shoots is necessary. The trial application of several plant auxins at different concentrations to decapitated stock plants identified a suitable technique to simulate apical dominance and temporarily suppress the production of replacement shoots. The synthetic auxin IBA most effectively controlled the production and growth rate of replacement shoots with the least amount of damage to the treated tissues. Auxin application apparently enhanced the growth of lateral branches in the whorl immediately below the treated stem, suggesting that grafted scions would not be adversely affected by auxin treatment. Routine application of auxin to plagiotropic grafts will reduce maintenance costs in seed orchards and clone banks of A. cunninghamii.     

Photosynthesis of oak leaves under water stress: maintenance of high photochemical efficiency of photosystem II and occurrence of non-uniform CO(2) assimilation

Shoot cultures of Quercus rubra (L.) were established from both juvenile and adult plant material. Initial explants from epicormic shoots formed on the basal zone of the trunks had a greater capacity for in vitro establishment than explants from crown branches. The growth of vigorous axillary shoots was obtained by culturing decapitated shoots horizontally on Woody Plant Medium supplemented with 0.2 mg l(-1) of 6-benzylaminopurine. After 3 weeks of culture the shoots were transferred to fresh medium for two more weeks, giving a 5-week multiplication cycle. Efficient shoot production was achieved by combining three treatments favoring the growth of lateral buds: excision of the apex, horizontal culture and cytokinin treatment. The addition of indoleacetic acid or indolebutyric acid to the multiplication medium did not improve shoot proliferation rates, and naphthaleneacetic acid was detrimental. Recycling the same explant for several successive subcultures improved the efficiency of the propagation procedure. Using the optimal multiplication procedures, nine clones (six of juvenile origin and three from adult trees) were tested in vitro and it was found that genotype and age affected performance.     

Patterns of shoot mortality in Betula platyphylla in northern Japan

To understand the development of crown structure in Betula platyphylla Sukatch., mortality patterns of long shoots were analyzed quantitatively. We selected 25 saplings growing under various light conditions and measured the relative photosynthetically active radiation (rPAR) at, and the three-dimensional position of, first-order branches. A long shoot was assigned "no buds" (NB) status if it lacked buds at the end of the growing season, including at the tips of short shoots. A long shoot was classified as dead if it was NB and all the offspring long shoots issuing from it were NB. The probability that a leafy long shoot (a current-year long shoot with leaves or an older long shoot with short shoots with leaves) would become NB by the end of the season was positively dependent on shoot age and branch age, and negatively dependent on shoot length, centripetal shoot order, branch height and rPAR at the branch. Randomization tests revealed that shoots became NB and dead in clusters of connected shoots. In particular, shoot clusters originating from 3-year-old shoots were more likely to die than expected if each shoot was assumed to become NB regardless of the connection. Stepwise logistic regression revealed that the maximum rPAR within the crown of an individual tree had a significant effect on the mortality rate of 3-year-old shoot clusters, together with the rPAR at the level of the branch and other structural entities. Correlative inhibition is an important mechanism for determining shoot mortality patterns.     

Height growth recovery and crown development in top‐damaged Pinus sylvestris trees

Leader shoot damage was imposed on young Scots pines (3 m high) in four ways: by caging the uppermost whorl including the leader shoot with 10 pine shoot beetles; by caging the two uppermost whorls with 20 beetles; by topping the tree below the 1984 whorl; by topping the trees as above and removing all current shoots in whorl 1983. Six years later, top‐damaged trees were still significantly shorter than undamaged controls, although the annual height growth rate had recovered to the pre‐damage level within 3 years. Recovery occurred in two ways: lateral branches from the nearest intact whorl took dominance over the damaged leader or secondary branches developed from interfascicular buds on the damaged leader shoot. Approximately one and two years of height growth were lost in the former and latter case, respectively. Only 5 of the 34 top‐damaged trees escaped technical defects (crooks and/or vertical branches). Stem diameter and crown development were slightly affected.     

扶风早实核桃枝条短截试验初报

扶风早实核桃由于结实早，结果多，分枝多，养分过度消耗，容易引起树势过早衰弱。通过进行顶梢、秋梢中部、春秋梢交界处、春梢中部短截处理，得出这些短截方法对新生枝条的数量、长度、粗度、时面积、副梢生长和剪口下枝条桔死长度都产生了不同程度的影响。从春梢中部短截修剪，能够刺激扶风早实核桃植株的生长，对增强树势和抑制枝条桔死有明显作用。     

Seasonal changes in bud dormancy in relation to bud morphology, water and starch content, and abscisic acid concentration in adult trees of Betula pubescens

Annual cycles of change in bud morphology, bud burst ability, abscisic acid (ABA) concentration, and starch and water content were studied in mid-crown terminal buds of short shoots and underground basal buds of Betula pubescens Ehrh. In particular, we investigated the roles of ABA and bud water content in the regulation of bud growth. Basal buds differed morphologically from terminal buds of short shoots in that their leaf initials did not develop into embryonic foliage leaves and their total size did not increase significantly during summer. Bud burst ability, measured by forcing detached short shoots and stumps under controlled conditions, was maintained in the basal buds throughout the year, whereas the terminal buds of short shoots remained dormant until October, thereafter their bud burst ability increased gradually and reached a maximum in March-April. The ABA concentration of the basal buds was relatively constant throughout the sampling period (1-3 micro g g(DW) (-1)), whereas that of the terminal buds of short shoots, which was much higher (5-10 micro g g(DW) (-1)), showed a distinct seasonal cycle with a maximum from August to November. Bud ABA concentration decreased during the first 10 days of forcing, especially in basal buds. In both bud types, the amount of starch increased toward the autumn, declined in November, and was negligible in the terminal buds of short shoots between January and March, but in April, the amount was high again in both bud types. Water content varied characteristically in both bud types, although more distinctly in the terminal buds of short shoots, with an increase in spring before bud burst and a decrease during the summer until September. The significant morphological and physiological differences between the mid-crown terminal buds of short shoots and the underground basal buds may partly explain the characteristic growth habit of the basal buds and their development into coppice shoots after cutting the tree. The results also indicate a role for ABA in maintaining dormancy of the terminal buds of short shoots and emphasize the relationship between tissue water status and ABA concentration.     

修剪和生长调节剂对青海云杉苗芽生长发育的影响

对5年生和7年生青海云杉苗进行了不同方式的修剪,同时用不同的生长调节剂对其主干和侧枝上的芽进行了处理,发现除去青海云杉顶芽,能够促进苗木侧芽和隐芽的生长发育,提高侧芽的抽枝率,增加新枝的生长量.不同种类的生长调节剂和修剪方式对青海云杉芽的生长发育影响效果显著不同,去顶芽修剪的效果优于纺锤形修剪和篱式修剪,对于7年生苗,主干上仅留3个饱满芽的强度修剪能明显地减少主干上的芽数,使抽枝数也随之减少,处理效果最差.去顶芽能够明显的增加当年新梢数量和长于6 cm的新梢总长度,同时还能增加当年新梢上冬芽数.6BA对青海云杉芽和枝条的生长发育有较好的促进作用,抽枝宝在各个修剪处理中表现均最差,甚至在一定程度上抑制了青海云杉芽的萌发和延长生长.修剪和生长调节剂处理对5年生苗侧枝芽抽枝数影响均极显著,而对7年生苗的影响却不显著;修剪和生长调节剂的交互作用明显地影响了对7年生苗的处理效果,而对5年生苗的影响不显著.去顶芽后再用6BA涂抹青海云杉苗上的保留芽,能有效地促进青海云杉保留芽的生长发育,有利于形成更多枝条,对青海云杉采穗圃苗的处理效果最佳,强度修剪和用抽枝宝抹芽不适于青海云杉采穗圃苗的培育.     

Rapid Micropropagation of Edible Bamboo Dendrocalamus asper

Abstract

Micropropagation protocols for Dendrocalamus asper using nodal shoots and seeds culture are described. Multiple shoots were induced through forced axillary branching. Ninety-five percent of the nodal shoot explants taken from juvenile primary and lateral branches, produced multiple shoots through axillary buds activation within 2 to 8 weeks on Murashige & Skoog's (MS) medium supplemented with 0.1-15 mg/l benzyladenine (BA). The cultured seeds also produced multiple shoots (1-20) within 6 weeks on this medium. The multiple shoot differentiation was influenced by the concentration of BA in the medium. The in vitro generated shoots were excised and subculture on MS + 3.0 mg/l BAP for further shoot multiplication. Fifteen to 20 fold rate of shoot multiplication was achieved by regular subculturing. These shoots were multiplied for more than 3 years without loss of vigor. Ninety-five percent of the shoots were rooted, when propagules (each consisting of cluster of 3 shoots) were transferred on to MS medium with 3.0 mg/l NAA or 10 mg/l indole-3-butyric acid (IBA).

To date, 18,000 plants (through axillary bud initiated from nodal ex-plants) and 6,000 plants from seed culture have been hardened and acclimatized. 12,000 plants have been field transferred.     

Participation of ascorbic acid in the dormancy establishment of poplar lateral branch buds

This work studied the participation of ascorbic acid (AA) in the dormancy establishment of apical buds of poplar (Populus deltoides Bartram ex Marshall cv. Catfish 2) lateral branches. AA content was highest during the active growth period and decreased to the lowest content during bud dormancy. The accumulation of the oxidised form, dehydroascorbate, was similar in either growth or dormant bud stages. The supplementation of buds with AA at the end of the summer delayed bud set. Similarly, the supplementation of buds with gibberellic acid extended the growth period and kept a high AA content in the apoplast. These results suggest that a decrease in the accumulation of reduced AA might be needed for the dormancy establishment in apical buds of poplar lateral branches.     

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。     

修剪对油茶春梢生长的影响

在冬季和初春两个时段分别对4个不同油茶家系进行修剪对比试验。结果表明:修剪对油茶春梢的长度、粗度、叶片数和有效芽数的影响显著,修剪后4个品种的各个指标都高于未修剪的对照;冬季修剪春梢的长度、粗度、叶片数和有效芽数都显著或极显著高于与对照,初春修剪除春梢的粗度外,其他各指标与对照的差异不显著;冬季修剪对春梢生长的效果优于初春修剪。     

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.     

Plagiotropism and auxin in Abies nordmanniana

Main branches of Abies nordmanniana Spach. were examined through their first growth season from subapical buds around the leader bud to fully expanded shoots. Plagiotropism was evident in branch orientation, which was almost horizontal, as well as in the orientation of buds developing on the branches. Auxin transport capacity was predominantly basipetal (> 90%) and consistently higher in the middle part of the branch than in the distal and proximal ends. Auxin transport capacity was higher on the dorsal side of the branch during the short initial hyponastic growth phase, but the difference disappeared when the branch became horizontal. No dorsal-ventral differences could be detected in young horizontal branches in concentrations of indole acetic acid, cytokinins, gibberellins or abscisic acid. Branch orientation was unaffected by decapitation of the leader apex or by decapitation and replacement with exogenous auxin. However, decapitation resulted in a less plagiotropic bud arrangement on the branches, and auxin application to the leader bud scar counteracted this effect. Thus, a signal originating in the stem seems to be involved in regulating branch bud positioning, whereas the horizontal branch orientation must rely on a different mechanism, presumably autonomic within the branch.     

木本植物构件生态学研究概述

在研究植物种群时,植物学家发现植物具有很高的可塑性,植物个体的枝、叶、芽、花、果实等方面均存在巨大的差异,因此很难对植物进行准确和细致的种群数量统计。而构件理论将植物种群分为群落水平的种群和个体水平的种群,从而可以很好地解决这一问题。文中回顾了构件生态学的发展历史以及木本植物枝、叶、芽等构件种群的研究进展,分析了木本植物构件生态学研究中存在的不足,并对如何应用构件生态学手段指导木本植物的生产实践提出了一些建议。     

Growth and branching habit of rooted cuttings collected from epicormic shoots of Betula pendula Roth

Patterns of shoot growth and branching were studied over two growing seasons in rooted cuttings collected from both epicormic shoots and seedlings of Betula pendula Roth. Epicormic shoots were induced to sprout on stumps and small logs of 5-, 10- and 30-year-old trees. The use of epicormic shoots enhanced the rooting capacity of stem cuttings collected from these shoots but did not appear to reverse the process of maturation. In this study, maturation was based on characteristics typical of mature trees but not necessarily those of the mother plant, because it was not possible to root cuttings, for comparison, from 5-, 10- and 30-year-old ortets, other than from epicormic shoots. There was evidence of the persistence of mature characteristics through an increase in shoot plagiotropism with increasing ortet age. Rooted cuttings from both seedlings and epicormic shoots, however, assumed an increasingly orthotropic habit with a smaller shoot angle at the end of the first growing season than at the beginning and this continued into the second growing season. Other indications of maturation, such as delayed bud flushing and the incidence of flowering with increasing ortet age, were also evident in rooted cuttings from epicormic shoots. There was a clear difference in branching habit depending on cutting source. Rooted cuttings derived from epicormic shoots produced nearly twice as many lateral branches compared with rooted cuttings collected from seedlings, but this was not an effect of maturation. There was some evidence that rooted cuttings derived from seedlings grew taller than rooted cuttings from epicormic shoots.     

无患子实生苗苗期生长动态研究

在福建省顺昌县开展无患子播种育苗试验,重点研究了其苗期生长动态,掌握无患子在一年中的生长特性,研究结果表明:无患子实生苗的苗高生长高峰期在6月到9月,其中以7月到8月生长最快,生长量占总生长量的41.8%,进入9月后苗高生长放缓;地径增长旺盛时期在8月至9月,生长量占总生长量的20%左右。进入10月后,无患子实生苗的生长逐渐以增粗为主,11月后,苗高生长基本停止。复叶片数的变化趋势与苗高基本一致,即生长高峰期出现在7-8月间。11月后幼苗陆续落叶,进入休眠期,因此,复叶片数出现生长曲线出现回落现象。同时,单株最大小叶叶长和叶宽的增长高峰期也分别出现在7月和8月。无患子实生苗从8月上旬开始有单株萌发侧枝, 8-10月单株侧枝数增加较为迅速,11月后侧枝基本停止萌发。但侧枝基径和枝长的生长并未有明显放缓或停滞。说明,此时的地上部分物质积累主要用于侧枝的生长。