Genetic variation and selection of 10-year-old Eucalyptus camaldulensis based on wind damage index and wood properties

Typhoons are becoming frequent and intense with ongoing climate change,threatening ecological security and healthy forest development in coastal areas.Eucalyptus of a predominant introduced species in southern China,faces significant growth challenges because of typhoon.Therefore,it is vital to investigate the variation of related traits and select superior breeding materials for genetic improvement.Variance,genetic parameter,and correlation analyses were carried out on wind damage indices and eight wood proper-ties in 88 families from 11 provenances of 10-year-old Euca-lyptus camaldulensis.The selection index equation was used for evaluating multiple traits and selecting superior prov-enances and family lines as future breeding material.The results show that all traits were highly significantly differ-ent at provenance and family levels,with the wind damage index having the highest coefficient of genetic variation.The heritability of each trait ranged from 0.48 to 0.87,with the wind damage index,lignin and hemicellulose contents,and microfibril angle having the highest heritabilities.The wind damage index had a positive genetic correlation with wood density,a negative correlation with lignin content,a negative phenotypic correlation and a negative genetic correlation with microfibril angle.Wind damage index and genetic progress in the selection of eight wood traits varied from 7.2%to 614.8%.Three provenances and 12 superior families were selected.The genetic gains of the wind damage index were 10.2%and 33.9%for provenances and families,and these may be starting material for genetic modification for wind resistance in eucalyptus and for their dissemination to typhoon-prone coastal areas of southern China.

Green synthesis, antimicrobial and cytotoxic effects of silver nanoparticles mediated by Eucalyptus camaldulensis leaf extract

Objective: To investigate the environmental-friendly extracellular biosynthetic technique for the production of the silver nanoparticles(AgN Ps) by using leaf extract of Eucalyptus camaldulensis(E. camaldulensis). Methods: The NP were characterized by colour changes and the UV-visible spectroscopy. The cytotoxic effects of prepared AgN Ps was detected against four types of pathogenic bacteria, including two Gram-negative bacteria(Pseudomonas aeruginosa and Escherichia coli) and two Gram-positive bacteria(Staphylococcus aureus and Bacillus subtilis) by using agar well diffusion method. Results: A peak absorption value between 400-450 nm for the extract and the colour change to dark brown were corresponding to the plasmon absorbance of AgN Ps. On the other hand, aqueous extract of E. camaldulensis leaves could be effective against tested microorganisms which showed inhibition zones of 9.0-14.0 mm. Furthermore, biologically synthesized AgN Ps had higher ability to suppress the growth of the tested microorganisms(12.0-19.0 mm). Conclusions: Our findings indicated that extracellular synthesis of Ag NPs mediated by E. camaldulensis leaf extract had an efficient bactericidal activity against the bacterial species tested. The exact mechanism of the extracellular biosynthesis of metal NP was not well understood. Further studies are needed to highlight the biosynthesis process of AgN Ps and also to characterize the toxicity effect of these particles.

Phytochemistry and larvicidal activity of Eucalyptus camaldulensis against malaria vector,Anopheles stephensi

Objective:To determine phytochemistry and larvicidal activity of Eucalyptus eamaldulensis against Anopheles stephensi.Methods:The chemical compositions of the leaf essential oils were analyzed using gas chromatography/mass spectrometry（GC/MS）.The larvicidal activity of essential oils and extract of leaf were tested against 4th instar larvae of laboratory-reared Anopheles stephensi.Results:GC/MS analyses identified the presence of 28 compounds corresponding to 99.60%of the total oil.The main constituents in the leaf essential oil were 1,8-cineole（69.46%）,γ-Terpinene（15.10%）,α-Pinene（5.47%） and Globulol（2%）.The leaf extract and volatile oil exerted significant larvicidal activity with LC50 values of 89.85 and 397.75 ppm,respectively.Clear dose-response relationships were established with the highest dose of 320 ppm essential oil extract resulted almost 100%mortality in the population.Conclusions:The larvicidal properties suggest that the essential oil of plant is a potential source of valuable larvicidal compounds against malaria vector and can be used as an alternative to synthetic insecticides.

Assaying the allelopathic effects of Eucalyptus camaldulensis in a nursery bed incorporated with leaf litter

Allelopathic effects of Eucalyptus camaldulensis Dehnh. were confirmed in Petri dish and pot experiments in our previous studies. However, the degree to which such effects under controlled experiments exist in more complex ecological settings remains to be tested. Thus, the present study was carried out by incorporating different proportions of ground litter of E. camaldulensis in soil. The growth of three agricultural crops: falen(Vigna unguiculata(L.) Walp.), chickpea(Cicer arietinum L.), and arhor(Cajanus cajan(L.) Millsp.), and two tree species, kala koroi(Albizia procera(Roxb.) Benth.) and ipil ipil(Leucaena leucocephala(Lam.) de Wit) were tested. There were inhibitory effects of leaf litter on germination, shoot and root growth, leaf number, and collar diameter as well as a reduction of nodulation by legume crops(25–80%reduction). The extent of the effects was dependent on the proportion of leaf litter, the species and the type of traits. In contrast to shoot growth, the effect on root growth was more severe. No effect on germination was found with the agriculture crops while the two tree species showed reduced germination. The effect was greater in the presence of higher proportions of leaf litter mixed in soil while in some cases lower proportions stimulated growth. Not all species were suppressed; A. procera, C. cajan, V. unguiculata showed compatible growth while C. arietinum and L.leucocephala were found incompatible. This study provides evidence that E. camaldulensis has allelopathic potential under field conditions and a careful selection of associated crops in agroforestry systems is highly recommended.

Native Woody Plants Diversity and Density under <i>Eucalyptus camaldulensis</i>Plantation, in Gibie Valley, South Western Ethiopia

The aim of the study was to assess the impact of E. camaldulensis plantation established in a semi-arid area on native woody plants diversity and density. Nested quadrant plot design, having an area of 15 m × 15 m used to collect data. Totally, 37 species at the plantation and 30 species at the native woodland, belonging to 24 families, identified. Species diversity (H′) was 1.57 at the plantation and 2.09 at the woodland forest. As for density of understory woody plants (height ≥ 1 m) the plantation forest harbored 6, 604 stems/ha while the native woodland had 7, 347 stems/ha. Seedling density (height Dodonaea angustifolia and other native species important for soil conservation, timber, bee forage and medicinal use.

Selection of Plus Tree Based on Growth Performance and Fiber Morphology Characteristics as Improved Sources for Propagation of <i>Eucalyptus camaldulensis</i>

One of the most successful techniques in planting trees is tree improvement in which trees with high qualities are selected for mass plantation. This study seeks to identify good properties of Eucalyptus camaldulensis through selective phases. Sixty Eucalyptus camaldulensis trees (30 ten-year-old and 30 five-year-old) were randomly selected through stratified sampling from two plantation sites in Kurdistan region, North of Iraq. The trees were examined for fiber morphology and quality parameters such as height, number of branches, diameter and straightness. In the first phase of property selection, sixteen trees with high rank in growth properties and fiber morphology were selected. In the final phase of selection, the selected trees were re-examined according to the number of properties and fiber morphology features and seven trees with the highest number of good parameters were chosen. The 7 selected trees had higher qualities in growth characteristics and fiber morphology compared with the other trees in the sample. This article reports on a selection method for E. camaldulensis trees through tree improvement techniques. The results of the study indicates that high genotype qualities were identified among both 5- and 10-year-old E. camaldulensis trees as the final selection consisted of three 5-year-old trees and four 10-year-old trees.

The Effect of Chlorine Dioxide Charges in Chlorine Dioxide-Alkaline Extraction-Chlorine Dioxide （DED） Sequence on Optical Properties of Kraft Pulp of Eucalyptus camaldulensis

Hardwoods are important raw material for making pulp and paper products. Eucalyptus camaldulensis is a fast-growing hardwood species with a wide distribution in Iran and can be introduced as appropriatematerial to compensate the wood shortages of the natural forest. Kraft pulping was performed under different cooking conditions and, based on the relations of pulp yield and kappa number, bleachable kraft pulp at screened yield of 43.3% and kappa number of 31.3 was selected for DED （Chlorine Dioxide-Alkaline Extraction-Chlorine Dioxide） bleaching and its bleachability was studied at different kappa factor in D~ stage. The results indicated that the bleachable kraft pulp from this species has high kappa number at acceptable screened yield and to complete the delignification in the bleaching process, higher kappa factor may be needed in DED bleaching sequence. The main reduction in final kappa number and yield loss were observed at kappa factor level of 0.2 but by further increase in kappa factor up to 0.4, more development were observed in optical properties but at lower opacity.

Particle Size Effects on Antioxydant and Hepatoprotective Potential of Essential Oil from Eucalyptus camaldulensis Leaves against Carbon Tetrachloride-Induced Hepatotoxicity in Rats

Particle size fractionation by sieving is used to optimize antioxydant potential of natural substances. The aim of the present study was to evaluate particle size effects on antioxidant and hepatoprotective potential of Eucalyptus camaldulensis essential oils (EO) on CCl4-induced hepatic damage in Wistar rats. Animals were daily orally treated with the EOs extracted by hydrodistillation from powder sieved at four particle sizes (≥355, 200 - 355, 100 - 200, ≤100 μm) and those of the unsieved powder at dose of 50 mg/Kg for 7 days. Compounds that are evaluated for these activities are hydrocarbons and oxygenated terpenes that were identified and quantified by GC/MS. Activities of enzymes markers of hepatocellular damage in serum and antioxidant enzymes in the liver homogenates were measured. In this research, EOs significantly prevented the increase in serum ALT and AST (p < 0.05), total cholesterol, triglyceride and LDL-cholesterol level in acute liver damage induced by CCl4 and significant increase level of plasma HDL-cholesterol. Also, significantly (p < 0.05) decreased the extent of malondialdehyde (MDA) formation and elevated the activities of superoxide dismutase (SOD) and catalase (CAT) liver in comparison to negative control group. The best antioxidant and hepatoprotective activities were those of EOs from two fine powder fractions (≤100 μm and 100 - 200 μm) was correlated to their high concentration in oxygenated terpenes (70.9% and 46.4%, respectively), when compared to the large particles (200 - 355 μm and ≥355 μm, with 33.3% and 41.8%, respectively) and unsieved powder (37.4%).

Chemical Variability and Antibacterial Activity of Eucalyptus camaldulensis Essential Oils from Senegal

1,8-cineole, also known as eucalyptol, is the main constituent and the most important of the leaf oils of many species of the genus Eucalyptus. In present study, the essential oils isolated by hydrodistillation from the leaves of Eucalyptus camaldulensis from six different locations were analyzed by GC-FID and GC-MS. Essential oil yields ranged from 0.33% to 4.35%. In total, 34 constituents were identified, accounting for 94.0% to 99.8% of the total compositions. 1,8-cineole (46.4% - 84.4%) was the main constituent of all the essential oil samples, except for one sample collected in the Fatick region, which had p-cymene (46.4%) and 1,8-cineole (26.0%) as major compounds. The essential oil showed excellent activity against S. aureus, E. coli and E. faecalis (IZ = 25.3 ± 1.2 mm;18.7 ± 0.6 mm;17.8 ± 0.3 mm, respectively) and moderate activity against P. aeruginosa (IZ = 10.8 ± 0.8 mm). They may have potential applications in food and pharmaceutical products.

Note on Glycaspis brimblecombei Moore (Hemiptera Psyllidae): A new pest of Eucalyptus in Greece

Leaves of eucalyptus infested by Glycaspis brim-blecombei Moore were found on river red gum (E. camaldulensis) and blue gum (E. globulus) trees in Attiki and Chania region, Greece. The psyllid is recorded for the first time in Greece. Brief information about this psyllid is provided.

Monoterpene hydrocarbons,major components of the dried leaves essential oils of five species of the genus Eucalyptus from Cote d’Ivoire

The chemical composition of the essential oils obtained from the dried leaves of five species of the genus Eucalyptus (E. camaldulensis, E. de-glupta, E. grandis, E. torelliana, E. urophylla) growing in C?te d’Ivoire, was analyzed by means of GC and GC/MS. The density and the refractive index were measured. The major components of all these oils are: α-pinene, β-pinene, α-phellandrene, limonene, γ-terpinene, p-cymene and β-caryo-phyllene. The particularity of these oils is their monoterpene hydrocarbons major components.

基于根系解剖结构的金沙江干热河谷土壤侵蚀速率估算

基于侵蚀过程会导致树木生长环境变化,进而改变根系生长生理特征的基本研究思想,以金沙江干热河谷龙川江流域为典型区,从树根细胞解剖结构和组合特征的变异中提取土壤侵蚀信息,探索和发展了基于树木生理生态的土壤侵蚀研究新方法与技术。结果表明,不同侵蚀强度下根系的年轮分布特征不一致,其中偏心率大小顺序为：局部暴露根系〉浅埋根系〉完全暴露根系,且偏心率与根系以上土层厚度、暴露程度存在显著性相关;根系导管面积是反演侵蚀过程的敏感指标,早材导管面积的变异是确定根系暴露时间的重要依据之一;龙川江流域土壤流失厚度为1.47~4.47 mm/a,平均侵蚀模数约为3 692 t（/km2.a）。

降低耐寒赤桉试管苗生产成本的研究

为了降低耐寒赤桉试管苗的生产成本,进行了培养基配制用自来水、山塘水、纯水代替蒸馏水,食用白糖代替蔗糖,培养基的不同形态,继代培养基二次利用和不同室内生根培养时间研究.结果表明,用自来水代替蒸馏水,试管苗的芽增殖倍数、生根率、发根量有所提高;以食用白糖替代蔗糖,对试管苗无影响;液体培养有利于试管苗的分化、生根和移栽成活;室内生根培养时间由常规的30 d缩短为15 d,不影响苗木的质量和移栽成活率.用自来水、食用白糖配制培养基,生根采取液体培养15 d,比用蒸馏水、蔗糖配制培养基,生根采取固体培养30 d,试管苗的直接生产成本可降低28%.

桉叶提取物抗菌作用及主要挥发性成分的年度变化

目的分析云南省临沧市永德县10年树龄赤桉、蓝桉和大叶桉的叶片提取物中挥发性成分的含有量变化情况,并研究其抑菌作用。方法连续12个月采摘3种桉叶片,阴干后分别用二氯甲烷和无水乙醇超声提取,对两提取物进行GC/MS分析,并用琼脂平板扩散法测定其抑菌活性。结果蓝桉含挥发性成分量最高,赤桉最低。无水乙醇桉叶提取物的抗菌活性均强于二氯甲烷桉叶提取物,对革兰氏阳性菌的抑制作用均强于对革兰氏阴性菌,但桉叶的主要成分1,8-桉叶油素抑菌活性很弱。结论同一月份3种桉叶提取物以及同一种桉叶不同月份提取物的挥发性成分含有量和抗菌活性均有差异,而且其抑菌成分可能与1,8-桉叶油素相关不大,需作进一步研究。

水分胁迫对赤桉苗木生长及生物量的影响和评价

通过对赤桉苗木进行3个水分胁迫强度,4个水分胁迫循环周期的试验,研究其对赤桉苗木的生长及生物量的影响。结果表明:不同水分胁迫强度和次数对赤桉苗木生长、生物量极其分配的影响显著,赤桉在水分胁迫下,生长受到抑制,根占总生物量的比例随水分胁迫梯度和次数的加大而增加;在不同的水分胁迫下,以间隔10天浇水的处理为最佳的水分胁迫梯度,第二循环周期为最适胁迫周期。

干热河谷区不同林龄赤桉叶中养分含量和再吸收率的比较及其线性回归分析

以种植于干热河谷区的赤桉(Eucalyptus camaldulensis Dehnh.)幼龄林、中龄林和成熟林为研究对象,分析了赤桉鲜叶和凋落叶中养分(包括N、P、K、Ca、Mg和Na)的含量和化学计量比,并计算各养分的再吸收率;在此基础上,对鲜叶和凋落叶中各养分的含量与再吸收率进行线性回归分析。结果表明:成熟林赤桉鲜叶和凋落叶的有机碳、全氮、全磷、全钾和全钠含量总体上高于幼龄林,而全钙和全镁含量则低于幼龄林;且鲜叶中的全氮、全磷、全钾、全钠和全镁含量总体上高于凋落叶,而有机碳和全钙含量则低于凋落叶。成熟林赤桉鲜叶和凋落叶的C∶N比、鲜叶的N∶P比和N∶K比以及凋落叶的K∶P比和Ca∶Mg比均低于幼龄林,但其鲜叶的K∶P比和Ca∶Mg比及凋落叶的N∶P比和N∶K比则高于幼龄林;且不同林龄鲜叶的C∶N比、K∶P比和Ca∶Mg比均低于凋落叶。各林龄赤桉叶的Ca再吸收率及幼龄林和中龄林叶的Na再吸收率均为负值,而其余养分的再吸收率均为正值;随林龄增长,N、K和Mg的再吸收率先升高后降低,而P、Ca和Na的再吸收率却先降低后升高;总体上看,赤桉叶中各养分的再吸收率从高到低依次为P、N、K、Mg、Na、Ca。线性回归分析结果表明:赤桉鲜叶的全钾和全钠含量分别与K和Na再吸收率呈极显著正相关(P<0.01),全钙含量与Ca再吸收率呈显著正相关(P<0.05);而凋落叶的全氮含量与N再吸收率呈极显著负相关,全镁含量与Mg再吸收率呈显著负相关。综合分析结果显示:林龄对赤桉叶的养分含量和再吸收率有明显影响,其保存养分的能力随林龄增长呈现先增强后减弱的趋势。

Feeding inhibition of Helicoverpa armigera （HiJbner） by Eucalyptus camaldulensis and Tylophora indica extracts

Crude leaf extracts of Eucalyptus camaldulensis and Tylophora indica were evaluated for their antifeedancy against Helicoverpa armigera larvae in no-choice bioassays. Cabbage leaf-disc dipped in different concentrations of leaf extracts was used for feeding fifth instars of H. armigera for 24 hours. Ethanol extracts from both the plant species exhibited significant feeding inhibition, activity. The effective concentrations of ethanol extracts that caused 50% reduction in larval feeding （EI50） were 6.9% for E. camaldulensis and 2.8% for T. indica, while these values of hexane extracts were 9.3% and 5.2%, respectively. Compared to the crude leaf extracts, crude alkaloids from T. indica and crude tannins from E. camaldulensis were more potent in reducing larval feedings.

Chemical characterization, release, and bioactivity of Eucalyptus camaldulensis polyphenols from freeze-dried sodium alginate and sodium carboxymethyl cellulose matrix

Crude ethanolic extract of Eucalyptus camaldulensis was encapsulated with sodium alginate- sodium carboxymethyl cellulose (CMC) using freeze-drying techniques. The microcapsules were characterized for particle size, morphology, physicochemical parameters, and micromeritics properties. Antioxidant and antimicrobial activities of the microcapsules were also demonstrated. Results revealed an irregular-shaped microparticles with a mean diameter ranging from 6.7 to 26.6 μm. Zeta potential and polydispersity index ranged from −17.01 to 2.23 mV and 0.34 to 0.49, respectively. Percentage yield ranged between 70.4 and 81.5 per cent whereas encapsulation efficiency ranged between 74.2 ± 0.011 and 82.43 ± 0.77 per cent. Swelling index and solubility varied inversely with extract concentration, with a range of 54.4%-84.0% and 18.8%-22.2%, respectively. Antioxidant activities varied directly with the concentration of the extract. Minimum inhibitory and minimum bactericidal concentrations of the microcapsules against Gram-positive foodborne pathogens ranged from 0.19 to 3.12 and 0.19-12.25 mg/ml, respectively. The Higuchi model indicated a time-dependent, delayed, and regulated release of polyphenols at 37°C. The results suggested that alginate-CMC possessed good encapsulant properties that preserved the bioactive extract, thus might be employed for application of natural products in food systems.

Estimation of water requirement per unit carbon fixed by Eucalyptus camaldulensis in semi-arid land of Western Australia

Afforestation in arid land is a promising method for carbon fixation, but the effective utili- zation of water is highly important and required. Thus, the evaluation of the amount of water per unit carbon fixed with the tree growth is required to minimize the amount of water supplied to the plants. In this research, a tree is regarded as a carbon fixation reactor with inflows of water and nutrients from roots, and CO_2 as the carbon source from leaves with outflow of water vapor from leaves and accumulation in the tree itself. In the process of photosynthesis and respiration nutri- tional elements are dissolved in water flow in trees. They do not flow out by these reactions, but are accumulated in trees. Thus, we have treated the behaviour of nutrients as a marker to evaluate the water/carbon ratio. Assuming that nutrient concentration is constant in sap, and the differences in the ratios of nutrient to carbon in living trees and dead (i.e. litter fall, etc.) are neglected, the ratio of the used water to fixed carbon is given as the ratio of nutrient to carbon in the tree body divided by the ratio of nutrient to water in sap. However, some nutrients are translocated and concentrated within the tree and some may be discarded through litter fall. Thus it is important to examine which nutrient element is the most suitable as the tracer. In this paper, the results of the above method applied to Eucalyptus camaldulensis in semi- arid land of Western Australia are shown. The value of water requirement per unit carbon fixation determined from potassium balance is between 421 kg-H_2O/kg-C for mature trees and 285 kg-H_2O/kg-C for young trees, while the values from calcium balance are much larger than these. The cause of the discrepancy between these values is discussed based on the measured element concentrations in sap and trees and the plant physiology. Finally, the actual average value through the life of a tree is suggested to fall between the two values.

Water Consumption of a Six-Year-Old River Red Gum Plantation in the Southern Zagros Mountains,Iran

Water is the most important limiting factor in the development of arid environments; therefore, optimization of water use is a necessity in desert reclamation projects. Evapotranspiration of a 6-year-old river red gum （Eucalyptus camaldulensis Dehnh.） plantation, located in a sedimentation basin of an artificial recharge of the Gareh Bygone Plain groundwater system in Iran＇s southern Zagros Mountains, was studied during a 7-month period. A neutron moisture probe was used to monitor soil water changes in the root zone. Soil water depletion following rapid drainage for blocks receiving relatively high, medium and low volumes of foodwater were 809.6, 312.4, and 203.1 mm, respectively, for a 150-day period. Soil water potential during most of the study period was below -1.5 MPa. This study proves that river red gum in not a suitable species for desertification control where water conservation is of vital importance. Flood irrigation of trees on 8 Aug. 1991 provided the opportunity to throw doubt upon the claim of summer dormancy of river red gum.