Response of clones of Eucalyptus microtheca to NaCl in vitro

We studied the response of nodal segments of Eucalyptus microtheca F.J. Muell. to salt stress in a tissue culture system. Three clones of Eucalyptus microtheca (37, 42 and 43) were grown in vitro under saline conditions (0-140 mM NaCl) for three months. The survival of all three clones decreased with increasing concentrations of NaCl in the medium, but the presence of up to 70 mM NaCl stimulated rooting in Clones 37 and 42. Shoot elongation of Clone 43 was less affected by salt than that of Clones 37 and 42. Leaf growth, expressed as leaf length, was stimulated 40% in Clone 42 and 33% in Clone 43, but was progressively inhibited up to 27% by 70 mM NaCl in Clone 37. Massive accumulation of Na(+) and Cl(-) occurred, especially in Clones 42 and 43 (4000 and 3000 mmol Na(+) kg(DW) (-1), respectively), as the salinity of the culture solution increased, and this was correlated with inhibition of growth. Because of a reduction in the accumulation of K(+) with increasing salinity, the K(+)/Na(+) ratio decreased from a control value of 4.5 to 0.14 in shoots grown in the presence of 140 mM NaCl. The development of techniques for selecting seedlings by monitoring the physiology of shoots in vitro instead of testing whole plants in vivo will provide a relatively simple method of selection for woody trees.     

Differentiation of seed germination and early seedling growth in ten provenances ofEucalyptus microtheca

An investigation of seed germination and early seedling growth ofEucalyptus microtheca was based on seed collection from 10 widely separated provenances in Australia. Genetic variation of seed germination and early seedling growth was observed among a series of provenances whose natural habitats range from different climatic condition. In the ten provenances, both the model of seed relative germination percentage and the model of seed total germination percentage fitted Logistic regression [y=a/(1+exp(-ex+b))]. In comparison with provenances from four high temperature (mean annual maximum temperature >30.0 °C; mean annual minimum temperature >17.0 °C) areas, six low temperature (mean annual maximum temperature <30.0 °C; mean annual minimum temperature <17.0 °C) areas showed the fast germination rate and the high total germination percentage. For each provenance we have 45 seedlings equally divided into three watering levels (100%, 50%, and 25% of field capacity), and studies on relationship between early seedling growth and climatic factors of the natural habitat of provenance. In control treatment, height growth of the seedling has been associated with intrinsically the driest quarter precipitation in the seed collection areas of provenance. In all the treatments, length growth of the biggest leaf of the seedling was related to mean annual maximum temperature and mean annual minimum temperature in origin of provenance. In contrast, basal diameter growth of the seedling was related to mean annual minimum temperature of the seed collection areas in water stress treatment. From an ecological viewpoint, the fast germination rate and the high total germination percentage of the seed and rapid early growth of the seedling appear to be favourable adaptations to the climatic conditions prevailing in the natural habitat of provenance. Responsible Editor: Chai Ruihai     

柳桉优良种源/家系的选择研究

对5年生的柳桉种源/家系试验林进行调查分析,结果表明:柳桉种源、家系间在树高、胸径和单株材积生长量上存在极显著差异,但主干通直度没有差异,而在主干明显度方面,种源间存在显著差异,家系间则没有差异;采用综合指数选择法选出了优良种源3个和优良家系20个,并从优良家系中选择优良单株20株,可作为无性繁殖的母本材料。     

耐寒桉树树种及种源引种试验

通过对永安国有林场1996年引种栽培的9种耐寒桉树连续6a的试验观测，结果表明：巨桉、邓恩按具有耐寒、速生、丰产等优良特性，可作为永安市及福建省冷凉地区发展桉树短轮伐期用材林主栽树种推广。     

永安市巨桉种源/家系引种试验

对福建省永安国有林场1997年引种的巨桉6个种源100个家系试验林进行连续8 a的试验观测,结果表明:不同种源、家系间的耐寒性和生长量存在显著或极显著差异。应用主成分综合评分排序法选出优良家系12个,其树高、胸径、单株材积和耐寒指数平均值分别为15.7 m、17.3 cm、0.1752 m3和4.40,增益分别为18.2%、19.6%、61.7%和18.4%;选出优良个体20株,其树高、胸径、单株材积和耐寒指数平均值分别为18.5 m、21.2 cm、0.2863 m3和4.85,增益分别为39.4%、46.3%、164.2%和41.3%。     

Eucalyptus camaldulensis provenances for afforestation in Mwanza and Shinyanga regions of Tanzania

Most parts of the Mwanza and Shinyanga regions of Tanzania face fuelwood and building-pole shortages. Two experiments using a total of 12 provenances of Eucalyptus camaldulensis Dehn. of Australian and local origin were tested at Igwata Forest Reserve, Tanzania for possible use in fuelwood and pole production. Assessment and analysis of data from the two experiments were made for survival and height growth, and for dbh development.Growth after 27 and 41 months in the two experiments indicate no significant differences in survival. Significant differences were, however, observed in height and dbh growth. It appears that Queensland provenances are the overall best-suited, followed by provenances from Northern Territory, Western Australia and Victoria. Limitations of the provisional results are outlined. Further trials with seed sources from Northern Australian provenance groups are recommended.A rotation age of about 4 years appears suitable for fuelwood, whereas a longer period might be needed for pole production if wood impregnation is not anticipated.     

耐寒桉树树种／种源引种试验研究

通过对永安国有林场1996年引种栽培的9种耐寒桉树连续6年的试验观测,结果表明巨桉、邓恩桉具有耐寒、速生、丰产优良特性,可作为永安市及福建省冷凉地区发展桉树短轮伐期用材林主栽树种推广造林.     

Relative susceptibility of Eucalyptus provenances to Cylindrocladium leaf blight in Kerala,India1

Susceptibility of 46 provenances belonging to 16 species of Eucalyptus to Cylindrocladium leaf blight caused by Cylindrocladium quinqueseptatum, C. clavatum and C. ilicicola differed significantly in detached leaf inoculations. Generally, susceptibility of a provenance to the three species of Cylindrocladium showed significant differences; only a few provenances gave either equally resistant or susceptible reactions to all the three species. C. clavatum was the most virulent species, C. ilicicola the least and C. quinqueseptatum intermediate.     

Susceptibility of Eucalyptus grandis provenances to a root rot associated with Ganoderma sculptrutum in Zimbabwe

Widespread cankering, gummosis, wilting and death of Eucalyptus grandis were first observed in Zimbabwe in 1956. Recent investigations have revealed the symptoms and deaths to be associated with infection by Ganoderma sculptrutum. Indigenous tree species, in particular Brachystegia spiciformis and Julbernardia globiflora, provide inoculum source for the fungus. A total of 170 half-sib families in 23 provenances were assessed for symptoms and death associated with G. sculptrutum infection. There were statistically significant differences (p ≤ 0.001) in observed symptoms among families in a provenance. Provenance differences were not significant (p > 0.05). There were significant differences among provenances (p ≤ 0.05) and families (p ≤ 0.001) for death associated with G. sculptrutum. Differences among the four blocks were significant for both symptoms (p ≤ 0.01) and death (P ≤ 0.001). Family heritability estimates ranged from 0.00 (±0.82) to 0.79 (±0.13) for symptoms and from 0.00 bb (±0.82) to 0.75 (±0.14) for death.     

Effect of NaCl and high pH on seedling growth of 15 Eucalyptus camaldulensis Dehnh. provenances

Eucalyptus camaldulensis Dehnh. is a moderately salt-tolerant Australian tree species widely used in farm forestry, often in salt-affected landscapes. In a glasshouse experiment, E. camaldulensis seedlings from 15 wide-ranging Australian seed sources (provenances), were cultured in sand-filled pots and treated for 57 days with control (no added NaCl in tap water, neutral pH), saline (150 mol m^–3 NaCl, stepped high pH (pH 7.6 to 9.5) and combined NaCl and high pH solutions. Significant differences were found among provenances in height and shoot dry weight. Differences in provenance response to treatment were found for dry weight but not for height. Reductions in shoot dry weight due to NaCl and high pH ranged from 42.9% to 82.0% and 4.3% to 51.7% respectively. Provenances from Lake Hindmarsh-SE (Victoria) and Lake Albacutya-N (Victoria) had relatively high tolerance to both stresses whereas those from Lake Albacutya-S (Victoria), Lowan Valley (Victoria), Silverton (New South Wales) and Katherine (Northern Territory) had low tolerance to both stresses. Provenances from De Grey River and Fitzroy River (Western Australia) were most tolerant of high pH. The performance of these provenances in this experiment generally accorded well with that in saline field environments.     

桉树枯萎病的病原鉴定

广东省河源市紫金县2006年发生大片桉树枯萎死亡,文章对此病害进行病原菌分离培养、致病性测定、病原菌鉴定等研究.根据病原菌的形态特征及致病性测定结果,将病原菌鉴定为尖镰孢霉(Fusarium oxysporum),这是在广东省对桉树枯萎病的首次报道.     

Influence of light availability on leaf structure and growth of two Eucalyptus globulus ssp. globulus provenances

Light availability strongly affects leaf structure of the distinctive ontogenetic leaf forms of Eucalyptus globulus Labill. ssp. globulus. Late-maturing plants from St. Marys, Tasmania and early maturing plants from Wilsons Promontory, Victoria (hereafter referred to as Wilsons Prom.) were grown for 9 months in 100, 50 or 10% sunlight. Growth, biomass and leaf area were significantly reduced when plants were grown in 10% sunlight. Provenance differences were minimal despite retention of the juvenile leaf form by the Tasmanian plants throughout the study. The time taken for initiation of vegetative phase change by the Wilsons Prom. saplings increased with decreasing light availability, but the nodal position of change on the main stem remained the same. Both juvenile and adult leaves remained horizontal in low light conditions, but became vertical with high irradiance. Leaf dimensions changed with ontogenetic development, but were unaffected by light availability. Juvenile leaves retained a dorsiventral anatomy and adult Wilsons Prom. leaves retained an isobilateral structure despite a tenfold difference in light availability. Stomatal density and distribution showed ontogenetic and treatment differences. At all irradiances, juvenile leaves produced the smallest stomata and adult leaves the largest stomata. Amphistomy decreased with decreasing irradiance. Detrended, correspondence analysis ordination highlighted the structural changes influenced by ontogenetic development and light availability. Adult leaves had characteristics similar to the xeromorphic, sun-leaf type found in arid, high-light conditions. Although juvenile leaves had characteristics typical of mesomorphic leaves, several structural features suggest that these leaves are more sun-adapted than adult leaves.     

桉树容器育苗常见病害及综合防治措施

根据蓝山县林业局近几年来的育苗经验，总结了桉树容器育苗过程中经常造成危害的猝倒病、茎腐病、灰霉病、桉白绢病、桉青枯病等5种病害，对这5种病害的病原及症状，在育苗过程中采取的各种预防措施进行了阐述。     

广东地区桉树病虫害调查初报

介绍近2年来对广东地区桉树病虫害调查的初步结果,分析了桉树病虫害发生的原因,提出了持续控制桉树病虫害的意见。     

桉树青枯病林地根际土壤营养分析

为了探讨桉树林地根际土壤营养状况与青枯病发生的关系,从广东省阳东县采集了3块不同健康状况样地的桉树林地根际土壤进行分析测定.结果表明:土壤pH值与桉树青枯病发病状况无显著相关性,土壤有机质、全氮、全钾含量在不同发病程度的样地间呈现健康林地＜中等发病林地＜严重发病林地的趋势.主成分分析表明,土壤有机质、全氮、全磷、有效磷4个成分的含量可能是反应桉树林地健康状况的主要因子.     

施矿物质对桉树红叶梢枯病防治试验

采用硼砂、硫酸锌、硫酸铜3种矿物质对红叶梢病防治，单一硼砂或硼砂、硫酸锌、硫酸铜混合防治均有明显效果，最好的是硼砂12g＋硫酸锌3g，其次是硼砂18g＋硫酸锌3g＋硫酸铜3g、硼砂18g＋硫酸锌3g。因此建议用硼砂＋硫酸锌防治桉树红叶梢枯病。     

Early growth and survival of Eucalyptus pellita provenances in a range of tropical environments,compared with E. grandis,E. urophylla and Acacia mangium

Provenance/family trials of Eucalyptus pellita F. Muell were established at three seasonally-dry tropical sites in northern Australia (two in north Queensland and one on Melville Island in the Northern Territory), and at Luasong, a tropical site with year-round high rainfall and humidity in Sabah, Malaysia. After 2–3 years, it was clear that New Guinea provenances outperformed Queensland provenances in their survival, growth and form, and in their crown health, in the humid tropical environment of Luasong. New Guinea provenances were also clearly superior to Queensland provenances in their growth and form at Melville Island, but less clearly so at Cardwell, Queensland. Among Queensland provenances, Helenvale and Kuranda were superior to the more northerly Cape York provenances, Tozers Gap and Lankelly Creek, while there was little difference between the two New Guinea provenances tested, Bupul-Muting (Irian Jaya) and Keru (Papua New Guinea). Significant differences in growth traits, form and survival were demonstrated between families within provenances. In a species/provenance trial at Luasong, E. pellita displayed better growth and survival than tropical provenances of E. grandis and E. urophylla, but was inferior in growth and crown health to Acacia mangium.     

桉树愈伤组织抗病性的测定及其快速繁殖研究

为了探索桉树抗青枯病树种的无性系快速筛选和繁殖技术,配制了3种类型的培养基,采用组培方法对桉树愈伤组织的抗病性和桉树无性系的快速繁殖方法进行了研究。结果表明:诱导愈伤组织形成的以MS+6-BA0.25mg/L+NAA0.5mg/L培养基最好;对愈伤组织芽的分化,最好的培养基是MS+6-BA0.25mg/L+NAA5mg/L;诱导生根以White+IBA0.5mg/L+2%蔗糖培养基为最佳;分别对桉树愈伤组织刺伤、幼苗伤根、幼苗截顶后接种青枯病,并测定它们的抗病性,其测定结果相同,说明可用桉树愈伤组织筛选抗青枯病树种。     

Polyphenols from Eucalyptus consideniana and Eucalyptus viminalis

From the leaves of Eucalyptus consideniana and E. viminalis, known hydrolysable tannins, galloyl esters and ellagitannins, were isolated. Flavonol glycosides were also isolated from the leaves of E. consideniana. The spectral data of the dimeric ellagitannin, oenothein B (1), are reported.     

速生桉生理性梢枯病严重发生原因及应急防治

多年现场考察和试验表明,速生桉生理性梢枯病发生范围越来越广,发病程度日趋严重。桉梢枯病主要症状有梢枯、枝条变形、树皮变褐、纵裂、颗粒状突起、小枝基部缢缩、树干变脆易折、叶片变色、叶脉凸起开裂等。桉梢枯病的主要原因是速生桉基肥、追肥存在问题,配方不科学等,提出了加强肥料质检、基肥中添加微量元素、追肥使用三元（微量元素）复合肥、每年追肥2次等应急防治对策。