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赤桉（Ｅｕｃａｌｙｐｔｕｓｃａｍａｌｄｕｌｅｎｓｉｓ）曾龄英（云南林业科学院昆明６５０２０４）赤桉是桉树中的一个重要树种，其用途最广泛，木材工业特性好，生长快，适应性强，是世界上干旱半干旱地区的主要造林树种，在适宜条件下产量很高。本文对赤桉作了全面介... 相似文献
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谷桉,澳大利亚俗称黑基杏仁桉,引进中国有的叫史密斯桉。在澳大利亚,天然分布于新南威尔士州南部和维多利亚洲东部的高地和悬崖上。分布纬度范围为南纬33.5°—37.75°;海拔500m;年降雨量750—1250mm,降雨量分布均匀,年中有3个月旱季。温度范围,最热月平均最高温度22°—28℃,最冷月平均最低温度2°—9℃,每年约有20天霜冻天气。谷桉在起源于玄武岩的肥沃土壤上可以长成巨树,高可达40-45m。多生长在冲积土和火山土上。谷桉的树冠浓密有光泽,树干下部为杏仁按类型树皮;即下部树皮纵深裂,粗糙;树皮黑色,树干上部和树枝为淡褐色,光滑, 相似文献
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邓恩桉在分类上属桉树属的双蒴盖亚属(subgenus symphyomyrtus)、蓝桉组(section maidenaria)多枝桉系(series viminales),形态特征和柳桉、巨桉相似。邓恩桉的天然分布在澳大利亚新南威尔士州东北和昆士兰州东南的较小区域,目前在新南威尔士州的天然林面积约800hm2,数量已不足82 000株,在昆士兰州的面积和数量都更小。因为数量小,邓恩桉在澳大利亚已被看作濒危树种,其天然分布区大多被划入国家公园或保护区,被保护了起来。邓恩桉的树体中等偏大,在开阔的生长条件下,分树大而浓密。它的成熟植株可高达50m,树干通直,枝下高能达到30￣35m。作… 相似文献
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Results from two coppice compared to replant trials are presented that originated from clone by site interaction (CSI) trials established on high? and low?productivity sites in subtropical coastal KwaZulu?Natal, South Africa. After the 84?month CSI trial measurements were completed the trees were harvested. Selected plots were allowed to coppice with the remainder replanted to the same four Eucalyptus grandis×Eucalyptus urophylla hybrid clones. Growth was higher at Kwambo Timbers (average mean annual increment [MAI] 34 wet white tonnes [wwt] ha?1 y?1), characterised by a higher mean annual precipitation, than at Palm Ridge (average MAI 11 wwt ha?1 y?1). In these trials coppicing of sufficient stumps per hectare (>1 000 stumps ha?1) resulted in similar volume production on the higher?productivity site and slightly improved (additional 3.4 wwt ha?1 y?1) yield on the lower?productivity site compared with the planted crop. The benefit of coppicing was mainly related to a reduction in the temporary unplanted period and reduced establishment cost. This study showed that coppicing can be a viable, cost?effective alternative to planting in commercial forestry if a number of criteria are met. However, it is recommended that the decision to coppice or to replant should be evaluated on a case?by?case basis. 相似文献
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Rogerio de Souza Noia Junior Genilda Canuto Amaral Jose Eduardo Macedo Pezzopane Mariana Duarte Silva Fonseca Ana Paula Camara da Silva Talita Miranda Teixeira Xavier 《林业研究》2020,31(3):797-806
Drought is considered the main environmental factor limiting productivity in eucalyptus plantations in Brazil. However, recent studies have reported that exposure to water deficit conditions enables plants to respond to subsequent stresses. Thus, this study investigates the ecophysiological acclimatization of eucalyptus clones submitted to recurrent water deficit cycles. Eucalyptus seedlings were submitted to three recurrent water deficit cycles and anatomical, morphological and physiological changes were analyzed. The results were:(1) Eucalyptus seedlings responded to water deficits by directing carbohydrates to root and stem growth;(2) Size and number of stomata were reduced;(3) Stomatal conductance decreased which allowed the plants to reduce water losses through transpiration,increasing instantaneous water use efficiency;(4) The relationship between gas exchanges and available water contents allowed the seedlings to uptake the retained soil water athigher tensions;and,(5) Physiological recovery from subsequent water deficits became faster. As a result of these changes, the eucalyptus seedlings recovered from the same degree of water stress more rapidly. 相似文献
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The preliminary assessment of progeny test in a seed orchard of Eucalyptus globulus Labill.ssp.globulus at Yipinglang State Farm of Yunnan Province in China was conducted.The trial was composed of 21 replications,with 2 trees on each plot,15 plots in each incomplete block,and 18 incomplete blocks in each replication,laid out in a α-design of 270 open-pollinated families.The families were of three categories (natural populations,local land race and seed orchard).They were further subdivided into 11 regions.The data from an assessment of growth,stem form and other characteristics of the young trees after being planted 2 years were analyzed.Results are as follows:the different categories differed significantly in their growth,with the families from seed orchards being the best.Regions also differed significantly in their growth.The families from the regions of Westem Victoria,Eastern Victoria and all three seed orchards were better than others.The tamilies from Yunnan had the best frost tolerant and its survival was the highest.For growth,stem form and fungal tolerance,the families from Yunnan were similar to that from Southern Tasmania and Eastem Tasmania.Two-tree plots were strongly recommended over singletree plot designs for large-scale progeny trials. 相似文献
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《Southern Forests》2013,75(4):185-188
Eucalyptus grandis × Eucalyptus nitens (G×N) hybrid clones are selected to combine complimentary characteristics of E. nitens and E. grandis. G×N hybrid clones also have the potential to increase growth rates and provide adaptability to a changing climate. A series of three trials planted across a range of high-productivity, mid-altitude sites in the KwaZulu-Natal midlands was established to test the suitability of a suite of G×N hybrid clones. Seven commercially available G×N clones together with two widely planted pure species controls, Eucalyptus dunnii and Eucalyptus smithii, were chosen for this study. The trials were set out in random complete block designs with nine treatments and four replications set out in square plots of 25 trees. The trials were measured for diameter at breast height at 23 months and monitored for snow damage over two winter seasons. Snow was noted at the Baynesfield site and subsequent snow damage assessments were performed. Basal area per hectare was calculated for each plot as a function of diameter at breast height and survival. Significant differences were observed between G×N hybrid clones in both growth and snow tolerance. The top-performing clones significantly outperformed both pure species controls in terms of growth and snow tolerance. Early results indicate that G×N hybrids may be better suited to high-potential, mid-altitude sites exposed to light snow risk than the currently recommended pure species. 相似文献
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ZHOU Yongdong** JIANG Xiaomei PIAO Chenghan Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2006,5(3):17-21
INTRODUCTION Eucalyptus plantations have been important plantations in South China for its fast-growth rate. And the overall planted area is beyond 1.6 million ha, mainly distributed in the provinces of Guangdong, Guangxi, Yunnan, Fujian, etc. But, the main utilization is limited to wood chips currently. Along with the natural forest protection policy implementation, the wood resource has transferred from the natural forest to plantation forests, and the value-added application of plant… 相似文献
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Garel Makouanzi Gilles Chaix Sophie Nourissier Philippe Vigneron 《Southern Forests》2018,80(2):151-158
Thirty-four Eucalyptus urophylla × Eucalyptus grandis hybrids were evaluated with a view to selecting for improved growth and wood-quality traits for plantations in the Congo. Height, circumference at breast height and volume were measured at 12, 27, 37, 49 and 60 months. Lignin content, the syringyl/guaiacyl ratio and total extractives content were predicted by near-infrared spectroscopy using wood powder samples collected from trees at breast height. While wood chemical properties were stable and under strong genetic control, growth traits were not. The genetic correlation between lignin content and growth was weak and negative, whereas the environmental correlation was also weak but positive. The genetic improvement of E. urophylla × E. grandis clones, based on growth features, leads to a limited decrease in lignin content and syringyl content and to a limited increase in extractives content. 相似文献
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从 Vakaneri 10年生的赤桉人工林中选择五株样木,研究它们的密度变化。研究的结果表明:1.密度(基本的和气干的)随高度而降低;2.平均基本密度为0.61～0.64克/立方厘米,15%含水量的密度为0.77～0.85克/立方厘米。 相似文献
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GONGMingqin CHEN Yu WANG Fengzhen CHEN YinglongResearch Institute of Tropical Forestry. Chinese Academy of Forestry Guangzhou . China 《中国林业科技(英文版)》2002,(1)
Bacterial wilt caused by Pseudomonas solanacearum, is a very serious disease of Eucalyptus in southern China, mainly in Guangdong, Hainan and Guangxi provinces. It causes the death of seedlings and young trees and the mortality may exceed 90 percent in some sites. Susceptible species include E. grandis, E. urophylla, hybrids between the two and E. citriodora. In nursery and field trials with E. urophylla and field trial with E. grandis x E. urophylla inoculation of ectomycorrhizal fungi was found to reduce the incidence of the disease. Some fungal isolates were more effective than others. 相似文献
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This paper deals with the photosynthetic properties of Eucalyptue camphoia. E. camaldulenaia. E. gunni-i. E. viminalia. E. giandia. E. dunii and E. maidenii. including the daily bariations of photosynthetic and respiratory rates, the comparison of the photosynthetic rates of various Eucalyriua spp. measured,the relationship between photo-synthetic rate and chlorophyll content, as well as the light saturation point. 相似文献
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Darío Navarrete-Campos León A. Bravo Rafael A. Rubilar Verónica Emhart Rebeca Sanhueza 《New Forests》2013,44(1):119-134
Genetic improvement of Eucalyptus genotypes for drought and frost resistance is essential for successful intensive management of commercial plantations. Understanding the physiological mechanisms that relate water use and frost resistance for highly deployed genotypes may allow for better prediction of their future performance, genetic selection and seedling management for site specific purposes. We studied whether instantaneous water use efficiency (WUE i ) may serve as drought, freezing and photoinhibition tolerance predictor by studying its response on six E. globulus clones (Eg1–Eg6) and four E. globulus × E. nitens hybrid seedlings (Egn1–Egn4) under drought and irrigated (control) treatments. Net photosynthesis (A) and transpiration (E) were studied using a gas exchange system in order to calculate WUE i (A/E). Simultaneous chlorophyll a fluorescence measurements were performed to assess the non photochemical quenching components. Frost tolerance of plants under control and drought treatments were evaluated by measuring temperatures that exert 50% photoinactivation of photosystem II. Finally, drought tolerance was evaluated by plant survival within each genotype after rehydration. Our results showed significant genotype variability in the rate of soil and xylem water potential decrease during drought. While most of the genotypes reached ?4.0 MPa in about 35 days of drought, genotypes Eg6 and Egn4 required 56 days of drought to reach this xylem water potential. WUE i exhibited significant differences among genotypes and irrigation treatments. Genotypes Eg5 and Egn4 increased their WUE i between 70 and 80% after drought. This was associated with a more conservative control of water loss at the stomatal level combined with maintenance of relatively higher rates of net photosynthesis than the other genotypes under drought conditions. Plants exposed to drought were more freezing tolerant than control plants, having in average 3°C lower LT50 than well irrigated ones. There was no a clear correlation between WUE i and drought tolerance or drought-induced photoinhibition, however WUE i was inversely correlated with LT50. Our results suggest that WUE i is not suitable by itself to select drought tolerant genotypes, but may provide evidence for discarding drought sensitive genotypes. In addition, it could provide valuable information to select for freezing tolerance. 相似文献
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《林业研究》2021,32(4)
Hybrid combinations of Eucalyptus have increased due to expansion of plantations into unconventional areas and to the search for higher quality timber.However,most of these species have difficulties surviving in vitro cultivation.Active chlorine and sealing systems are often used to reduce contamination and increase gas exchange.The aim of the present study is to evaluate the establishment,multiplication,elongation and adventitious rooting of E.grandis × E.urophylla.Two clones(C1 and C2) and four active chlorine concentrations(0.000%,0.001%,0.003%,and 0.005%) were tested in the establishment and multiplication phases.Three sealing forms(W/M,1/M and 3/M) and the same four active chlorine concentrations were applied to the elongation phase.Two luminosities(dark and light)and three sealings(W/M,1/M and 3/M) were tested during adventitious rooting.Active chlorine concentration of0.005% led to the lowest fungal contamination rate and to the highest in vitro establishment.Active chlorine concentration of 0.003% resulted in the greatest length and highest number of shoots per explant in the multiplication phase.There were no phytotoxicity problems and the quality of plants grown in an environment with active chlorine was maintained in comparison with those grown in an autoclave.The increase in gas exchange in ventilation systems had a positive impact on the in vitro growth and development of plants. 相似文献
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《林业研究》2017,(1)
Genetic transformation systems require protocols that allow regenerating transgenic plants from transformed tissues. This study aimed to establish a protocol for indirect organogenesis in leaf explants of a Eucalyptus grandis × E. urophylla AEC 224 clone. During callogenesis stage, several concentrations of NAA and then NAA or 2,4-D combined with TDZ were tested in JADS culture medium for 30 days, followed by subculture of the explants in the regeneration medium, containing 5.0μM BA and 0.5μM NAA for another 30 days. In these media,the explant oxidation rate was high(95 %). Thus, in order to reduce oxidation, different culture media were compared: WPM, MS, JADS and modified QL, followed by explant transfer onto regeneration medium. The highest percentage of regeneration and the lowest oxidation rate were achieved on WPM medium. Then, NAA and 2,4-Dwere tested in combination with TDZ and also TDZ and BA combined with NAA in WPM medium. The most efficient culture media in terms of shoot regeneration were WPM supplemented with 0.25μM TDZ and 0.1μM NAA during 30 days for callus induction and then with 5.0μM BA and 0.5μM NAA for another 30 days. This protocol yielded a regeneration rate of 43 %, with a low oxidation of tissues. A rooting experiment was conducted using half strength MS medium and comparing three concentrations of IBA(2.46, 4.90 and 7.35μM). The highest rooting percentage(35 %) was obtained on medium containing2.46μM IBA. Once the shoots were rooted, acclimatization in a greenhouse was not challenging and plant survival reached 100 %. 相似文献
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Tropical provenances of Eucalyptus camaldulensis Dehnh. and E. tereticornis Smith were studied, in their natural habitat in Australia and in a 3.75-year-old progeny trial in Zimbabwe, for their potential to produce medicinal-grade essential oils. Substantial interand intra-specific variation in the contents of five prominent monoterpenes, 1,8-cineole, -pinene, -pinene, limonene and p-cymene was found. Plantations of E. camaldulensis established in the wet/dry tropics using seed from Petford in northern Queensland offer immediate potential for oil production. Other widely-planted Queensland provenances with oil potential are Gilbert River Bridge E. camaldulensis and, after some genetic improvement, E. tereticonis from Morehead and Kennedy Rivers. Select individual trees at Petford provide oil of enhanced quality, at about double the yield of average trees. 相似文献
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Gisela Manuela de Franca Bettencourt Carlos Ricardo Soccol Thais Salete Giovanella Luziane Franciscon Daiane Rigoni Kestring Isabel Rodrigues Gerhardt Juliana Degenhardt-Goldbach 《林业研究》2020,31(2):507-519
Genetic transformation is becoming routine for engineering specific traits in important clones of recalcitrant species such as Eucalyptus;however,the efficiency is still low for most species,so many researchers still use seeds instead of clones as initial explants.This work aimed to develop a genetic transformation protocol,based on a highly efficient in vitro organogenesis protocol,for an Eucalyptus urophylla clone selected in our breeding program.Plant growth regulators were evaluated for indirect organogenesis and rooting.In a two-step protocol,the combination of callus induction media supplemented with 0.5 μM thidiazuron+0.5 μM naphthaleneacetic acid(NAA)and shoot induction media supplemented with 5.0 μM benzylaminopurine+1.0 lM NAA allowed up to 85.6%shoot formation with more shoots per explants when compared with other concentrations.Transgenic plants expressing the uidA gene were obtained using Agrobacterium tumefaciens and selected for kanamycin resistance.A RAPD analysis was used to check for somaclonal variation.In tests using 11 RAPD primers,we did not observe somaclonal variation in the in vitro stages evaluated. 相似文献
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Wood density influences both the physiological function and economic value of tree stems. We examined the relationship between phosphorus (P) supply and stem wood density of Eucalyptus grandis Hill ex Maiden seedlings grown with varying soil P additions and determined how changes in wood anatomy and biomass partitioning affect the relationship. Plant height, stem diameter and total biomass increased by 400-500% with increasing P supply. Stem wood density decreased sharply from 520 to 380 kg m(-3) as P supply increased to 70 mg P kg(soil) (-1). Further increases in P supply to 1000 mg P kg(soil) (-1) had no effect on wood density. The increase in wood density at low soil P supply arose principally from enhanced secondary wall thickening of stem fiber cells. Cell wall thickness increased from 3.6 to 4.5 microm as soil P supply decreased. Because fiber cell diameter was independent of soil P (12 microm +/- 0.3), the proportion of the stem occupied by cell wall material increased as P supply declined. The enhanced secondary wall thickening of stem fiber cells at low P supply was not associated with changes in whole-plant biomass partitioning. Instead, low P supply appeared to alter biomass partitioning within the stem in favor of secondary wall thickening. Thus, increased wood density in E. grandis seedlings grown at low P soil supply was associated with inhibited stem cambial activity, resulting in an increased proportion of photoassimilates available for secondary wall thickening of fiber cells. 相似文献