红豆杉属幼苗繁殖技术的研究进展

红豆杉属([WTBX]Taxus[WTBZ])是珍贵的药用植物,其紫杉醇的大规模开发应用加剧了资源短缺。本文概述了红豆杉属植物的区域分布、生境和群落学研究结果,重点综述了幼苗培育途径及技术关键。种子繁殖的关键是破除休眠和苗期遮荫;扦插繁殖的关键是插条年龄及长度、药剂品种与处理时间、扦插基质与季节、圃地荫棚与保暖设施的优化配套;组培繁殖的难点是根系诱导和幼苗芽丛形成。现阶段红豆杉属植物的规模化发展宜以扦插供苗为主、辅以种子育苗、攻关组培苗繁殖。     

白豆杉及其繁殖

白豆杉(PseudotaxuschieniiCheng.)系红豆杉科白豆杉属植物,分布范围较窄;叶常绿,种子有白色肉质假种皮,颇美观,具有较高的科研价值和观赏价值。     

粤北南方红豆杉的群落类型及物候与繁殖生物学特性

对粤北地区的南方红豆杉（Taxus maikrei）植物进行物候学观察,以有植物群落调查,并着重研究其种子萌发和插插繁殖特性,结果表明,在粤北地区,南方红豆杉主要分布于南亚热带中亚热带典型的常绿阔叶林中;种群个体顶芽展梢在4月中旬开始,5月中旬雄球花现蕾,花期7月底至11月下旬,8月下旬雌球花现蕾,花期10月下旬至次年1月底,果期在次年10月上旬,10月下旬顶芽形成;在自然条件下种子需2－3年才能萌发;在山地条件下对种子进行湿沙藏,再播入沙床中,萌发率达到95．2％,但周期较长（1年半）;在实验条件下对种子采用为温层积（先25℃36周,再转入5℃12周,共48周,共48周,即336d）,取出培养萌发率最高,达82．2％;扦插繁殖方面,以成熟一年生枝为插穗,用生根粉ABT1浓度在100mg.L^-1时处理效果较好,扦插时间在10－11月份最适合,生根率达95％。     

新型树种猫儿屎的繁殖

猫儿屎(Decaisnea fargesii Franch.)是木通科猫儿屎属的一种野生植物资源,用途广泛,值得开发利用。采用扦插繁殖和种子播种繁殖,提高苗木产量和苗木种植成活率。     

杜鹃花属植物扦插繁殖研究进展

我国有着丰富的杜鹃花资源,但有关其繁殖应用的研究还具有一定的局限。种子育苗耗时长,组培育苗成本和技术要求高,都不适于杜鹃花属植物的大面积生产。扦插繁殖快,还可保持母本的优良性状。从插条的选择,准备,插条的生根激素处理,扦插基质的选择,外界环境条件对扦插成活率的影响及扦插后的养护管理等六个方面对杜鹃的扦插繁殖技术的研究进行综述,以期推进杜鹃花属植物,尤其是中国野生杜鹃的引种驯化和大面积的推广应用。     

IBA与NAA对桃金娘扦插繁殖的影响

采用二元二次回归通用旋转组合设计,探讨植物生长调节剂IBA、NAA对桃金娘Rhodomyrtus tomentosa扦插生根的影响。结果显示,适宜浓度的IBA和NAA有利于桃金娘的扦插生根,IBA对生根率、根长和根重的影响更为明显。最佳浓度组合为IBA、NAA各100 mg·L~(-1),用该组合处理插条,可有效地提高扦插繁殖的成活率及幼苗质量。     

濒危乔木红豆杉不同更新阶段的生境特征比较

以福建梅花山自然保护区濒危乔木红豆杉(Taxus chinensis(Pilger)Rehd.)为对象,对红豆杉的种子排放、幼苗更新、幼树更新3个更新阶段的生境特征进行研究,并比较生态位的变化,以此评价红豆杉不同更新阶段的生境需求。结果显示:随着个体发育生长,红豆杉更新生境发生了明显转变,种子排放地与幼苗生境空间一致性较高,而它们与幼树生境存在明显的空间不一致性。从生态位角度来看,种子排放地和幼苗生境重叠指数≤0.5的仅有海拔和坡度2个因子,这说明幼苗的空间格局受到鸟类传播的强烈影响,鸟类传播所排放的种子能萌发并生长成幼苗。幼苗和幼树生境重叠指数≤0.5的因子有海拔、坡向、植被类型,说明在大尺度景观因子和庇护植被层面上,植物的更新需求出现了明显的不一致。研究结果表明红豆杉的更新生境存在明显的阶段变化,可能造成植物更新出现建成限制,使幼树阶段成为更新的瓶颈阶段。     

绞股蓝繁殖试验研究

报道绞股监种子繁殖和扦插繁殖的试验结果,为绞股蓝人工培提供繁殖技木。     

萝芙木的保育研究

萝芙木属(Rauvolfia Linn.)植物富含的单萜吲哚类生物碱在降压、抗心律失常、抗肿瘤等方面都有重要的药用价值.为缓解野生萝芙木资源濒危的状况,萝芙木的保育需要同时满足资源量和药用质量两种需求.对萝芙木保育的种子繁殖、扦插繁殖、组织培养、栽培管理、收获部位及药用质量评价进行了综述,着重梳理了建立萝芙木离体再生体系的最优组培条件和毛状根诱导及生产利血平等生物碱的研究进展,指出了目前萝芙木保育中存在的问题和未来的研究方向.     

南方红豆杉不同扦插时间对成活率影响

南方红豆杉种子产量低,休眠期长,自然存有量和栽植数量少,人工造林种苗需求量大。为促进南方红豆杉的可持续利用,对南方红豆杉不同扦插时间繁殖作进一步探索。通过试验,插床的蔽光度为60%,用清水沙做基质、一年生枝条做插条,经过药剂处理,湿度保持在70%~80%,得出南方红豆杉以11月下旬扦插繁殖效果较好,成活率达78%。能批量生产,满足人工造林的种苗需求。     

Vegetative propagation of Cecropia obtusifolia (Cecropiaceae)

Cecropia is a relatively well-known and well-studied genus in the Neotropics. Methods for the successful propagation of C. obtusifolia Bertoloni, 1840 from cuttings and air layering are described, and the results of an experiment to test the effect of two auxins, naphthalene acetic acid (NAA) and indole butyric acid (IBA), on adventitious root production in cuttings are presented. In general, C. obtusifolia cuttings respond well to adventitious root production (58.3% of cuttings survived to root), but air layering was the better method (93% of cuttings survived to root). The concentration of auxins used resulted in an overall significantly lower quality of roots produced compared with cuttings without auxin treatment. Future experiments using Cecropia could benefit from the use of isogenic plants produced by vegetative propagation.     

Stimulation of adventitious rooting of Taxus species by thiamine

Summary Results obtained from using root inducing compounds on Taxus species cuttings suggested that rooting could be significantly enhanced by the presence of thiamine. This observation was verified using a root inducing solution containing a set concentration of IBA (0.2%), NAA (0.1%), and supplemented with various concentrations of thiamine. The best rooting response for Taxus cuspidata stem cuttings was found using this solution supplemented with 0.08% thiamine. Rooted cuttings were easily established and developed into vigorous plants. In addition, Taxus brevifolia shoots obtained from tissue cultures via in vitro organogenesis also responded favorably to this 0.08% thiamine supplemented rooting solution.     

Adventitious rooting of conifers: influence of physical and chemical factors

In conifers, vegetative propagation of superior genotypes is the most direct means for making large genetic gains, because it allows a large proportion of genetic diversity to be captured in a single cycle of selection. There are two aims of vegetative propagation, namely large-scale multiplication of select genotypes and production of large numbers of plants from scarce and costly seed that originates from controlled seed orchard pollinations. This can be achieved, in some species, either through rooted cuttings or rooted microshoots, the latter regenerated through tissue culture in vitro. Thus far, both strategies have been used but often achieved limited success mainly because of difficult and inefficient rooting process. In this overview of technology, we focus on the progress in defining the physical and chemical factors that help the conifer cuttings and microshoots to develop adventitious roots. These factors include plant growth regulators, carbohydrates, light quality, temperature and rooting substrates/media as major variables for development of reliable adventitious rooting protocols for different conifer species.     

Greenhouse propagation of Cannabis Sativa L. by vegetative cuttings

Previous work revealed significant variations in cannabinoid profiles ofCannabis sativa L. derived from a single seed source (P.1. 378939) and subjected to the same growth environment. Studies were conducted to evaluate the efficacy of propagation ofC. sativa by vegetative cuttings in order to increase uniformity of cannabinoid concentrations within a given plant population.C. sativa was successfully propagated by vegetative cuttings. However, there were both morphological and biochemical differences between seed-derived plants and their vegetative propagules. Delta-⁹-tetrahydrocannabinol concentrations were 4.1 times higher in vegetative propagules than in seed propagules. Vegetative cuttings also generally developed more profuse lateral branch growth; hence, foliage increased relative to their parent plants. Cannabinoid levels within the population of vegetative cuttings remained highly variable.     

湘西南龙底自然保护区油料植物组成与资源价值分析

分析了龙底自然保护区油料植物组成与资源特点。结果表明：（1）油料植物107科281属477种,其中精油植物131种,樟科（7属27种）、芸香科（6属21种）、唇形科（11属17种）等11个科为优势科,以木本植物为主,占73.38%。（2）以种子种皮为主要含油部位的植物占71.47%,植物含油量＞20.0%的有211种,＞50.0%的43种;油脂脂肪酸含量＞70.0%的有7科11种,亚油酸含量＞70.0%的有12科20种。（3）在精油植物中,57种植物含精油量＞1.0%,13种＞4.0%。龙底自然保护区内油料植物资源丰富,特别是富油植物资源种类较多,是油料植物富集之地,具开发利用潜力。     

云南省红豆杉资源的分布,利用现状与保护和可持续利用

红豆杉属（ＴａｘｕｓＬ．）植物是提取抗癌新药紫杉醇（ｔａｘｏｌ）的原料,在云南省有２种１变种,分布范围较广,但多散生,野生数量计有３５４０９２０株。近年来,红豆杉资源的开发利用研究进展较快,但资源的破坏和浪费严重,加之该植物生长缓慢,对生境的要求高,营造原料林困难,供求矛盾十分突出,为此提出了红豆杉资源的保护和可持续利用对策。     

Do propagation methods affect the fine root architecture of African plum (Dacryodes edulis)?

Belowground tree growth attributes determine whether associations will be complementary or competitive in an agroforestry context. A study on fine root (d?≤?2?mm) distribution patterns of Dacryodes edulis based on root density (RD), root length density (RLD) and root weight density (RWD) was conducted to evaluate the effect of propagation methods on rooting distribution. Results showed that D. edulis trees of seed origin had greater RD (P?≤?0.001) than trees of vegetative origin (cuttings and marcots) in the upper soil stratum (0–30?cm). Similarly, in the uppermost soil stratum (0–10?cm), RLD and RWDs varied significantly (P?<?0.01). Trees of seed origin had an exponential distribution pattern for fine RD, RLD and RWD with depth to 80?cm. In contrast, the distribution pattern of fine roots of trees of vegetative origin (cuttings and marcots) were quadratic for the same variables which increased in the 20–30?cm soil depth stratum before declining steadily to a depth of 80?cm. The findings of this study suggest that D. edulis trees of vegetative origin (cuttings and marots) are likely to be less competitive than trees of seed origin when intercropped with shallow-rooted annual plants in an agroforestry system for belowground resources.     

The first trees. The Archaeopteris model

The earliest self-supporting organisms exceeding 2 m in height evolved about 370 million years ago, approximately 100 million years after the rise of the first land plants. Evidence for the tree habit is usually indirect and assessed from the diameter of the available stem fragments. Four systematic groups of Devonian plants evolved the tree habit independantly: the Lycopsida, Cladoxylopsida, and progymnosperms in the Middle Devonian, the Equisetopsida in the Late Devonian. All share a free-sporing life cycle which limits their habitats to wet areas. Their branching pattern involves the strict division of their apices, whether equally or unequally. The progymnosperm genus Archaeopteris was widespread worldwide and evolved the highest trees of the Devonian (maximum height estimated at 40 m). Besides it ecological significance as the dominant component of the earliest forests, Archaeopteris currently represents the closest known relative to the seed plants with which it shares two derived characters, the heterosporous life cycle, and the possession of leaves. Another distinctive feature of Archaeopteris trees is represented by the double function of their wood for both support and conduction. New analyses involving vascular trace analysis in anatomically preserved specimens have demonstrated that Archaeopteris is not the simple tree reconstructed by Beck (1962). In this fate model, Archaeopteris consisted of an erect trunk bearing short-lived, flattened, leaf-like branch systems forming a terminal crown. New evidence indicates that laterally to these appendages of apical origin, a new type of branches, of adventitious origin, evolved which development compares to that of the axillary branches of the seed plants. These branches which were large and long-lived represent major architectural components of the tree. Evidence for vascular structures comparable to those produced on stem cuttings in modern plants suggest that Archaeopteris may have evolved vegetative strategies for propagation. The set of "modern" characters of Archaeopteris may explain its success until the Devonian/Carboniferous boundary when its extinction is correlated to the radiation of the earliest seed plants.     

Facilitation by herbivore-mediated nurse plants in a threatened tree, Taxus baccata: local effects and landscape level consistency

We investigated the regeneration of a threatened tree, the yew Taxus baccata, in relation to the presence of fleshy‐fruited woody plants acting as seed dispersal foci as well as protecting yew recruits against ungulate herbivores. We seek to determine if local facilitative effects are consistent across landscape in the Cantabrian range (NW Spain). Yew seed rain by birds mostly concentrated under yew trees and beneath hollies Ilex aquifolium. Seedling emergence distributed similarly to seed rain, but first‐year seedling survival was higher beneath hollies. In one site where woody vegetation was structured as nucleation centres (multispecific patches of fleshy‐fruited plants acting as foci for seed rain) yew recruits mostly occurred in yew‐dominated centres, suggesting dispersers‐mediated facilitation. However, holly was the main nurse plant for most of these recruits, considering the nurse as the species whose canopy covered directly the yew recruit. Living beneath nurse plants reduced herbivore damage on saplings and enhanced seedling survival. A planting experiment with yew rooted‐cuttings beneath different spiny shrubs corroborated this effect. Additional evidence on yew recruitment limitation by herbivory emerged from one population where ungulates were fence‐excluded. Our results suggest that nurse plants mitigate the negative effect of herbivores on yew regeneration, by providing defence against browsing and trampling. Shelter ability related to nurse structure, cone‐shaped shrubs with branches at their bases acting better as a barrier. Paradoxically, this structure resulted from heavy browsing on nurse plants. The study of yew regeneration and habitat structure in seven sites provided evidence for the consistency of facilitation by holly at the landscape level, since local values of yew recruitment positively related to nurse ground cover. Range‐scale yew management must consider the local functioning of the interaction among avian seed‐dispersers, nurse fleshy‐fruited plants and ungulate herbivores, in combination with regional measures, targeting the habitats where facilitation emerges.