Vascular modifications in Platanus acerifolia seedlings inoculated with Ceratocystis fimbriata f. sp. platani

Vascular modification of plane tree seedlings inoculated with Ceratocystis fimbriata f. sp. platani, the canker stain disease agent, were characterized using histochemical and scanning electron microscopy methods.     

First report of Ceratocystis platani in Albania

The fungus Ceratocystis platani was detected in various localities of the Gjirokastër prefecture in southern Albania, where it was causing widespread mortality on Platanus orientalis trees. The identification of the fungus was based on both morphological characteristics in culture and DNA sequencing. The pathogenicity of C. platani was confirmed in inoculations on seedlings of P. orientalis. To our knowledge, this is the first report of C. platani in Albania.     

Ophiostoma tsotsi and Ophiostoma quercus associated with Platypus cylindrus F. (Coleoptera: Curculionidae) in cork oak stands in Tunisia

Ambrosia beetles, including Platypus cylindrus, commonly act as vectors of Ophiostomatales. In an investigation of fungi associated with P. cylindrus, several species of Ophiostomatales were identified, including two species of Ophiostoma s. str. These two species were characterized based on comparisons of DNA sequences of the internal transcribed spacer regions including the 5.8S gene of rDNA and β‐tubulin gene. Two distinct clades were discernable in the phylogenetic trees, supported by high bootstrap values. One clade included the species Ophiostoma tsotsi, reported herein for the first time in Tunisia, and the species Ophiostoma quercus.     

Ceratocystis platani is killing plane trees in Istanbul (Turkey)

Ceratocystis platani was detected at several locations in the European side of Istanbul, causing severe dieback and mortality, mainly on Platanus × acerifolia imported from Italy approximately 160 years ago, but also on Platanus orientalis. In the work reported here, the causal agent of the dieback and mortality was identified based on morphological characteristics in culture and internal transcribed spacer (ITS) sequencing, confirming the presence of C. platani in Turkey. All analysed C. platani isolates from Istanbul shared the same ITS sequence with European C. platani strains available in the NCBI, but differed from other species previously ascribed to the Ceratocystis fimbriata species complex. Pathogenicity of C. platani was proven by inoculation onto 25‐cm‐long and 4–9 mm diam. P. orientalis twigs and the causal agent reisolated from symptomatic tissues. In a survey of 976 Platanus in streets and parks of Istanbul, 26.5% of trees showed symptoms of C. platani infections, whilst 5.6% were dead. The proportion of symptomatic trees was higher where management interventions, such as topping or pruning and felling infected trees had been carried out.     

Observation de sensibilités differentielles de quelques organes de Platanus acerifolia vis-à-vis de Ceratocystis fimbriata f. platani

Differences in susceptibility against Ceratocystis fimbriata f. platani between organs of Platanus acerifolia. Artificial inoculations in various organs of young plane-tree seedlings showed different degrees of susceptibility for different tissues. While herbaceous and slightly lignified parts (leaves, stem top) proved to be relatively resistant, rootlets were very effective sites of infection. The theoretical and epidemiological consequences of these findings are pointed out.     

大连地区法国梧桐繁育技术

法国梧桐是大连地区应用最广泛的园林绿化树种。文章介绍了法国梧桐的形态特征及生态习性,总结其繁育技术。     

桥山林区法桐扦插育苗技术

本文立足桥山林区立地条件,根据法桐的生物学特性,法桐扦插育苗应把好插穗采集、插穗储藏、整地、插穗处理、扦插及扦插后管理等技术环节,为黄土高原地区法桐育苗提供技术保障.     

Volatile organic compounds (VOC) as biomarkers for detection of Ceratocystis platani

Ceratocystis platani causes canker stain of plane trees, and it represents a serious disease of Platanus spp. both in the United States and Europe. Current chemical or biological controls do not effectively manage C. platani, so new preventive methods need to be developed in order to limit this pathogen spreading. In this work, we have characterized the main volatile organic compounds (VOC) emitted in vitro from pure cultures of C. platani and other common pathogenic fungal species of hosts plants growing in the same ecosystems as plane trees. We found that C. platani emitted a similar blend of VOC compared with phylogenetically similar species C. populicola. In particular, C. platani was characterized by emission of isoamyl acetate and isobutyl acetate while C. populicola by ethyl acetate and isobutyl acetate, which were not released by any of the other out‐group fungal species grown on the same medium. Moreover, following a targeted approach based on the main VOC found in vitro, we have successfully validated in vivo that VOC uniquely emitted by C. platani (i.e. isobutyl acetate along with isoamyl alcohol) were released from the bark of plane trees following C. platani inoculation. Our results highlight the possibility to exploit VOC emitted specifically by C. platani as biomarkers to recognize Platanus x acerifolia plants infected by this pathogen.     

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.     

悬铃木体细胞胚胎发生及植株再生

以叶片为材料 ,研究了悬铃木的体细胞胚胎发生及其植株再生。结果表明 ,悬铃木幼苗叶片在WPM 0 1mg·L- 1 IBA 5 0mg·L- 1 BA培养基上的愈伤组织诱导率和胚性愈伤组织诱导率分别为 10 0 %和 89 1% ;2 5℃的温度有利于胚性愈伤组织在WPM 0 5mg·L- 1 BA培养基上进行体细胞胚胎发生 ;黑暗低温处理 (10℃ ) 3d不但可以促进体细胞胚胎的发生过程 ,而且可以提高其发生频率。     

Accumulation of heavy metal in Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia

Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma (ICP). We investigated the uptaking ability of lead (Pb) and cadmium (Cd) by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index (MAI). Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves (2.21) and F. rotundifolia had the highest MAI value for shoots (2.4).     

三球悬铃木树皮的酚类化学成分研究

研究了三球悬铃木树皮的酚类化学成分.采用SephadexLH-20柱色谱及薄层色谱等方法进行分离,从其70%丙酮提取物乙酸乙酯溶性部分中分到11种化合物,经波谱分析及理化性质化合物分别鉴定为:儿茶素、表儿茶素、没食子儿茶素、表没食子儿茶素、山奈酚、槲皮素、阿福豆苷、异槲皮苷、紫云英苷-6″-没食子酸酯、异槲皮苷-6″-没食子酸酯和酪醇.11种化合物均首次从该树种中分得.     

三球悬铃木叶的解剖结构

采用石蜡切片法制片对三球悬铃木（法国梧桐）叶片解剖结构进行研究。结果表明：三球悬铃木叶由表皮、叶肉和叶脉三部分组成,叶片厚度142.4μm。三球悬铃木叶主脉上下的表皮细胞小且排列紧密;只在上表皮分布栅栏组织,海绵组织发达;叶脉发达;气孔密度大,31.63个/单位面积。抗旱性比一球悬铃木差。     

Response of Platanus orientalis leaves to urban pollution by heavy metals

Atmospheric pollution is an important concern in urban environments.The impact of urban pollution on the physiological,biochemical and anatomical properties of leaves of oriental plane(Platanus orientalis L.)was studied.The leaves were collected from an urban site(Tehran,Iran)and a non-urban forest park(Chitgar Forest Park).Anatomical(stomata,parenchyma,and cuticle)and physiological(chlorophyll content,enzyme activities)properties were analyzed.The concentrations of Cd(cadmium),Pb(lead),Ni(nickel),and Cr(chromium)in leaves were significantly higher and Zn(zinc)lower at the urban site relative to the forest park.Chlorophyll a,total chlorophyll,and carotenoid content in leaves of the urban site were significantly less than those of the forest park,but there was no significant difference in chlorophyll b.In addition,the activities of superoxide dismutase,catalase,ascorbate peroxidase,and guaiacol peroxidase in urban leaves were significantly higher than in the leaves of the forest park.In the urban area,leaves experienced a significant decrease in leaf surface area,stomata density,stomata pore area,epidermis,and spongy mesophyll thickness,but a significant increase in cuticle and palisade thicknesses relative to forest park leaves.The increase in enzyme activities may indicate that the trees are attempting to cope with increased reactive oxygen species(ROS)because of pollution-induced stress.Our study suggests that oriental plane trees alter their physiological and anatomical properties when living in a polluted urban environment.     

Action in vitro de fongicides benzimidazoles et thiophanates sur Ceratocystis fimbriata E. et H. f. platani

In vitro action of selected benzimidazole and thiophanate systemic fungicides on Ceratocystis fimbriata E. et H. f. platani. The relative effects of several systemic fungicides (benzimidazoles: carbendazim, benomyl, and thiabendazole; and a thiophanate: methyl-thiophanate) of French strain of Ceratocystis fimbriata E. et H. (platani were studied in vitro by measuring mycelium diameter growth, percent conidiospore germination, and development from chlamydospores. Both strains were sensitive to carbendazim and methyl-thiophanate. These chemicals inhibited mycelium growth and development of chlamydospores.     

Residual tree damage along skidding trails in beech stands in Greece

We studied the damage caused to unfelled trees during skidding operations in four beech stands of northern and central Greece that were managed under differing harvesting systems.After timber was harvested we recorded and analyzed all damage to a width of 2 m along both sides of the skid trails.The percentage of damaged residual trees was 17–28 %.Higher numbers of saplings were uprooted or destroyed in parts of the stands with high natural regeneration.Most damaged trees suffered 1.33–1.90 wounds that were inflicted up to a height of 1 m above ground level.At all sites mean wound sizes were large,89–1190 cm2,and caused elevated risk of future fungal infection.The damage caused by skidding during timber harvesting can be minimized by better planning the harvest operations,and training forest workers in reduced impact logging.