Physiological responses of Eucalyptus spp. hybrids to infection by Ceratocystis fimbriata

In Brazil, the selection and planting of eucalyptus clones resistant to Ceratocystis fimbriata is the pre‐eminent control strategy for the wilt pathogen. However, little is known about host defence responses associated with resistance of eucalyptus to C. fimbriata infection. In this work, enzymatic activity, sugars, lignin, total phenols and phenolic compounds involved in the defence response of eucalyptus clones resistant (RC) and susceptible (SC) to the Ceratocystis wilt were evaluated. Changes were detected in the sugars produced by RC clones, with higher concentrations occurring compared with SC. A similar response occurred with lignin content at 28 days after inoculation (dai) in RC plants. SC plants had an increase in polyphenol oxidase and peroxidase activities at 7 dai. In contrast, RC plants demonstrated high activity of the same enzymes at 2 and 4 dai, decreasing afterwards. There was no difference in phenylalanine ammonia‐lyase activity between resistant and susceptible clones. Hydroxycinnamic acid concentration was higher in RC than in SC; however, there was no difference between RC and SC in flavonoid concentrations. RC had high concentrations catechin, chlorogenic acid and caffeic acid. Histochemical tests demonstrated the presence of phenolic compounds and lignin, at higher intensities, in xylem of RC plants. Inoculation with C. fimbriata induced defence responses in both resistant and susceptible eucalyptus clones, but both the intensity and speed of the responses were higher in RC. Alterations in the concentrations of sugars and lignin, as well as certain enzymes and phenolic compounds, could be used to predict the relative susceptibilities to Ceratocystis wilt of different phenotypes of eucalyptus clones.     

A serious new wilt disease of Eucalyptus caused by Ceratocystis fimbriata in Central Africa

In a recent survey of Eucalyptus clones in the Republic of Congo, Central Africa, a serious wilt and die-back disease of two different hybrid clones was observed. Affected trees ranged in age from approximately 6 months to 4 years. Isolations from symptomatic plant material consistently yielded a Ceratocystis species. On the basis of morphology and sequence data this fungus was identified as Ceratocystis fimbriata, a well-known wilt and canker pathogen of many economically important plants. The Eucalyptus isolates were compared with other Ceratocystis spp. based on sequence data generated from the ITS and 5.8S region of the rRNA operon. The results confirmed the identity of the Ceratocystis isolates from Eucalyptus as C. fimbriata and showed that they group with other C. fimbriata isolates from Brazil, South Africa and Europe. Inoculations on young Eucalyptus plants were conducted in the greenhouse and all three of the Congolese isolates tested, produced typical lesions in the bark and xylem. This study represents the first report of C. fimbriata as a pathogen of Eucalyptus in Africa. This is a serious new disease that will require considerable study in order to ensure that losses, caused by C. fimbriata, do not continue.     

Electrophoretic protein profiles of strains of Ceratocystis fimbriata f. sp. platani

Soluble proteins extracted from the mycelium of strains of Ceratocystis fimbriata (Ell. et Halst) Davidson f. sp. platani Walter were separated on native and SDS-polyacrylamide gradient gel electrophoresis. The protein patterns were compared and the electrophoretic profiles of all the strains examined showed striking intraspecific similarities. The use or protein banding patterns as a diagnostic criterion to distinguish strains of C. fimbriata is discussed.     

Ceratocystis fimbriata of plane trees in Italy: biological aspects and control possibility

The biology of the pathogenic agent of plane tree canker (Ceratocystis fimbriata f.platani), the vectors of the disease and the results of some preventive and curative treatments are described in detail.     

桉树袋蛾的危害及防治措施

介绍了桉树袋蛾的主要种类及其生物学特性,并阐述了防治措施,以期为桉树袋蛾的防治提供参考。     

Growth and behaviour of Ceratocystis fimbriata in Plane-tree tissues A scanning electron microscope study

Ceratocystis fimbriata(Ell. et Halst.) Davidson f. platani Walter development in Plane-tree (Platanus Orientalis L.) tissues was examined by scanning electron microscope. All the fungal elements are smooth except for doliform endoconidia which are characterized by a rough surface and protruding rims. The fungus penetrates lesions and spreads rapidly along medullary rays into the pith and finally into the xylem elements. The hyphal presence in pith cells causes the disappearance of plastids and breakdown of the middle lamellae. The internal walls of vessels are not affected by hyphal activity during the period of the study.     

Morphological and cultural variation of Seiridium spp. from cankered Cupressaceae hosts in New Zealand

Studies of Seiridium. spp. isolated from cankered cypresses and related hosts in New Zealand indicate that only 2 species are present, namely, 5. unicorne and 5. cardinale, following sdtton, and not 3 species as proposed by boesewinkel. Apart from a difference in the presence/absence of conidial appendages, the two pathogens are similar in many biological characteristics. Isolates of S. unicorne showed a continuum of variation in conidial size and cultural morphology making it difficult to justify splitting of the species.     

施肥对桉树幼林生长量的影响

通过正交试验设计探索施用不同种类肥料、不同施肥方法对不同家系桉树幼林生长量的影响差异,结果表明:在福建省闽南海拔700 m以下丘陵山地以尾细桉M1(A3)+0.3 kg.株-1(分2次施)磷酸二铵(B1)+开放射沟施的方法(C3)最好,1 a高生长量达7.3 m、胸径达4.2 cm。     

桉树红叶枯梢病的防治试验

通过试验研究施肥种类、施肥数量、施肥方法对桉树红叶枯梢病防治效果的影响差异,结果表明,施用不同数量硼及不同施肥方法对桉树红叶枯梢病防治效果的影响差异显著;以150g磷酸二铵＋硼15g（A3）＋放射沟施（B3）组合最好,平均红叶转绿率达98.2％,平均抽高达到103．4cm。     

桉树优良无性系工厂化育苗技术

从桉树优良无性系工厂化育苗的生产流程入手，系统地介绍了桉树优良无性系组培苗的培育和以组培苗营养袋苗为母株，建立采穗圃，培育大量插条用以生产扦插苗的技术。其间以尾巨桉EF7为例，插入组培苗芽增殖培养基选择，促进生根培养基的选择，以及扦插条激素处理选择等的试验方法及过程，以加强桉树优良无性系工厂化育苗技术体系的力度。     

桉树害虫油桐尺蛾林间防治试验

对桉树害虫油桐尺蛾幼虫进行林间药剂防治试验,结果表明:使用单剂生物药剂0.6%阿维菌素水剂4 000倍液、16 000 IU.mg-1苏云金杆菌粉剂1 000倍液喷雾防治幼虫,10 d后的防治效果达89%~97%;使用混合化学药剂A3B3C3、A2B2C3和A1B3C3这3种组合喷雾防治油桐尺蛾幼虫,7 d后的防治效果达84%以上;使用混合生物药剂a1b1c2、a1b3c3和a1b1c1这3种组合喷雾防治油桐尺蛾幼虫,10 d后的防治效果达80%~96%;使用烟雾剂柴油5 kg+20%氰戊菊酯乳油0.375 kg、柴油5 kg+20%氰戊菊酯乳油0.25 kg、柴油5 kg+20%氰戊菊酯乳油0.125 kg喷雾防治幼虫,7 d后的防治效果达89%以上。     

广西速生丰产桉树病害调查

对广西速生丰产桉树Eucalyptus spp.进行了比较系统、全面的传染性病害调查,共鉴定出30种传染性病害,即15种主要病害和15种次要病害。其中4种主要病害和8种次要病害为广西新记录病害。对主要病害的症状特点和危害程度进行了描述,并提出综合治理建议。     

Pestalotiopsis biciliata,a new leaf pathogen of Eucalyptus spp. recorded in Italy

The present paper describes new symptoms on Eucalyptus spp. in Central Italy associated with the fungal pathogen Pestalotiopsis biciliata. This fungal species has been previously recorded in Italy on grape associated with fruit rot. Artificial inoculation trials on leaves confirmed the pathogenicity of the fungus to Eucalyptus camaldulensis. P. biciliata is included in the list of Pestalotiopsis spp. responsible for leaf disease on eucalypts worldwide.     

四川桉树适生种及栽培技术

根据四川省的气候和桉树的生物学特性 ,将四川省划分为盆地、攀西河谷阶地和干热河谷 3个栽培区。针对不同的栽培区 ,提出相应的适宜桉树种 ,并对巨桉、直干蓝桉、赤桉等树种的不同培育目标的栽培技术进行了总结。     

"根太阳"生根剂在桉树扦插育苗中的应用

“根太阳”生根剂是一种新型的分子信号诱导型生根产品 ,能快速诱导桉树插条生根。生根方式为环状生根 ,根量大、颜色白、质量好、活力强。与常见的激素类生根产品相比 ,“根太阳”能使桉树插穗提早 4d左右生根、提前 1周出圃 ,生根率高于常见生根产品 1 1 %～ 2 6 5 % ,平均生根数提高 1 8～ 8 5根 /插穗。这种新型的植物生根促进剂把桉树扦插育苗技术提高到一个新的水平     

桉树免炼山轻度耕作法造林效果研究

以炼山造林为对照,研究了桉树免炼山轻度耕作法造林效果,结果表明:免炼山轻度耕作法造林可节约生产成本300元/hm2、增加立木材积20.4 m3/hm2.免炼山轻度耕作法造林可有效减少水土流失、保护林地生态环境,具有应用推广价值.     

红壤侵蚀区桉树经营模式研究

为探寻适合在红壤侵蚀区应用和推广的桉树经营模式,对红壤侵蚀区的多种桉树营林措施进行了调查和研究。结果表明：炼山有利于桉树初期的生长,但2年后,采取不炼山处理的桉树林地,桉树胸径和树高生长速度开始超过炼山处理的桉树林地,而采取全面清除植被处理的桉树林地,桉树胸径和树高的生长速度始终最慢;采取前埂后竹节沟的水保措施较不采取水保措施更有利于桉树的生长;夏季劈草对桉树生长最为有利,秋季次之,春季再次之,然后是冬季劈草和不劈草处理,且春季和秋季劈草效果差距不大,冬季劈草和不劈草无显著差异。     

不同桉木化学机械法制浆性能的研究

研究了尾巨桉、巨尾桉、尾叶桉、蓝桉及小叶桉这5种桉木的材性特征及其预处理-碱性过氧化氢化学机械浆(P-RC APMP)制浆性能。结果表明:5种桉木的综纤维素质量分数在77.96%~81.36%之间,小叶桉最高,巨尾桉最低;木质素质量分数在23.18%~26.62%之间,尾叶桉的最高,巨尾桉最低;纤维平均长度在755~785μm之间,差异较小。采用P-RC APMP制浆方法,在H2O2用量5%,Na OH用量4.5%浸渍条件下,小叶桉的制浆得率最高,达86.7%,巨尾桉最低,仅为84.2%;在相同加拿大游离度(300 m L CSF)下,蓝桉浆的强度性能和光学性能最优,纸浆的抗张强度和白度分别达30.13(N·m)/g和82.5%(ISO),且所需磨浆电耗最低,仅1 188 k Wh/t,巨尾桉浆的强度性能和光学性能最差,纸浆的抗张强度和白度分别为16.9(N·m)/g和73.8%(ISO),且所需磨浆电耗最高,约为1 370 k Wh/t。     

Molecular characterization of Ralstonia solanacearum infecting Eucalyptus spp. in Brazil

Among the bacterial pathogens of Eucalyptus in Brazil, Ralstonia solanacearum is considered one of the most important because of the characteristics of the pathogen, like the high diversity among the strains related to host range, high virulence, broad geographical distribution and its damage to the crop in recent years. Given its importance and the lack of research on this pathosystem, the present study aimed to perform a molecular characterization of different strains of infected Eucalyptus plants in Brazil. A total of 19 bacterial cultures isolated from Eucalyptus in different regions of Brazil were analysed. A 372‐bp product generated by multiplex‐PCR amplification using Nmult primers identified all the strains analysed as belonging to phylotype II. Eighteen strains were grouped into subclade IIA and one into subclade IIB. The phylogenetic tree generated from the gene sequences of endoglucanase (egl) confirmed the classification of the strains into phylotype II and separated the strains into sequevars. Strains AMC22, IBSBF2568 and IBSBF2576 were grouped into a single clade, as were strains UFV18 and UFV20, with 89% and 78% a posteriori probability, respectively, forming two new potential sequevars not yet defined. We also identified strains belonging to sequevars 41 (100% probability) and 37 (88% probability). However, most of the strains did not fit into any previously described sequevar and did not form distinct clades. The results of the analysis of fragments amplified using the ERIC‐PCR technique indicated the existence of genetic diversity among the strains studied, with a generally high correlation between similarity and the geographical origin of the strains.