The detection of poplar mosaic virus and its occurrence in a range of clones in England and Poland

The incidence of poplar mosaic virus evidenced by foliage symptoms, enzyme-linked immunosorbent assay (ELISA) or bioassay (infectivity) was greater in stooled clones having Aigeiros (especially as the female) parents than in those of Tacamahaca parentage. The overall prevalence of the virus in clones growing in England was less (84/344, 24%) than in clones growing in Poland (143/256, 56%). Whereas symptoms in PMV-infected P. deltoides were prominent and common, in P. nigra, another species assigned to the Section Aigeiros they were indistinct and rare. Evidence of poplar mosaic virus inferred from ELISA alone was found in only one aspen of 52 tested clones in the Sections Leuce, Leuce × Leuce or Leucoides.     

The impact of industrial air pollutants on the occurrence of several important pathogenic fungi of forest trees in Poland

The occurrence of the more important pathogenic fungi of forest trees in the areas affected by industrial air pollutants in Poland has been investigated. The fungi are seen to respond in a pattern such that SO₂ and its derivatives act either fungistatically, or as stimulators depending on concentration.     

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.     

Pathogenic variation of Seiridium spp. isolated from cankered Cuppressaceae hosts in New Zealand

Field and glasshouse inoculation tests with isolates of S. cardinale and S. unicorne (Cke & Ell.) Sutton on C. macrocarpa and C lusitanien showed symptoms caused by the two pathogens to be indistinguishable. Isolates of S. cardinale showed an overall higher pathogenicity and less variability than those of S. unicorne. Neither pathogen seemed capable of infecting hosts outside the Cupressaceae, An isolate of Boesewinkel originating from Crvptowcria and supposed to be a distinct species from the anamorph of Lepteutypa cupressi, failea to infect Cryptomeria; neither could L. cupressi and S. cardinale, though all of them readily infected C. macrocarpa and C. lusitanica. Isolates of S. unicoene showed vast differences in pathogenicity in any one test, but many of the Isolates also showed extremi pathogenicity variation between repeat tests, hence pathogenicity determination became uncertain or probalistic. There is no evidence that the decline of S cardinale in this country is due to reduced pathogenicity or to possible interaction with S. unicorne in host infection.     

Tiarosporella durmitorensis sp. nov. – a new pathogenic fungus on needles of Abies alba

A fungus causing necrosis and needle cast has been discovered on fir trees (Abies alba) in a hight of 1700 m above sea level in Yugoslavia. The intensity of infection was very high, and the needles of all age classes were infected. The consequence of the infection is the death of the tree. The pathogen is described as a new species Tiarosporella durmitorensis Karad?i?. So far, this fungus has been found only in European silver fir stands in the National Park Durmitor and in the National Park Biogradska Gora (Montenegro).     

Tree chitinases – stress‐ and developmental‐driven gene regulation

In recent years, a considerable number of studies have harnessed the power of genomics to decipher the role of pathogenesis‐related (PR) proteins in plant defence against various biotic and abiotic stresses. Chitinases are PR antifungal proteins expressed constitutively at low levels in plants and induced during biotic pressures and are demonstrated to be involved in the plant defence responses. Remarkable induction of chitinase enzymes by various abiotic agents (salicylic acid, jasmonic acid, ethylene and ozone) and biotic components (pathogens, insect pest, fungal cell wall components and oligosaccharides) is well demonstrated in plants. Several reviews on plant chitinase expression during host–pathogen interaction are available for annual species, whilst reports of their expression in tree species are limited to a few woody perennials: Populus, Pinus, Picea, Eucalyptus, Castanea and Pseudotsuga. The aim of this paper is to review the induction of chitinase during various stresses and developmental processes in forest tree species.     

Patterns of bark beetle occurrence in Norway spruce stands of national parks in Tatra Mts. in Poland and Slovakia

This paper presents the results of a research project concerning bark beetle populations in Norway spruce stands managed under a nature protection regime in national parks in Tatra Mountains in Poland and Slovakia. The preliminary data on bark beetle occurrence and related selected stand characteristics are presented. The dynamics of a bark beetle outbreak that occurred from 1994–97 in the stands localized on both sides of the state border and in various nature protection regimes is analyzed retrospectively. The data concerning the tree/stand characteristics, i.e. DBH and increment of trees are discussed in relation to its potential role in the mechanism for the spread of bark beetle populations. The patterns of the spatial distribution of trees attacked during the research period (1999–2001) are described.     

Inonotus dryadeus in North America: new records,hosts, distribution and incidence

Inonotus dryadeus is newly reported in eastern Canada (Ontario) on Acer platanoides and Acer saccharinum, both new hosts, and Ulmus americana. The host range, incidence, and available distributional data in continental North America are summarized in a table. The fungus occurs primarily on Quercus, Abies, and Tsuga. Occasionally, it is found on Picea and Pinus as well as many other hardwood trees. Colder climates and host differences in the boreal forests may be limiting distributional factors. Inonotus dryadeus appears to favour very old trees. The maximum known width of the fruiting body is revised upward to 74.9 cm.     

南岭发现金斑喙凤蝶2个新寄主

2009年6月和8月在对南岭国家级自然保护区的蝴蝶区系调查中发现,金斑喙凤蝶在金叶含笑和乳源木莲上产卵,卵孵化后取食其嫩叶,确定此2种植物是金斑喙凤蝶的寄主植物,有可能还是该蝶的嗜食性寄主植物。此发现有助于开展金斑喙凤蝶保护生物学研究,有着重要的生态意义和科学价值。     

Nasa,Nemesia and Euphrasia: new alternate hosts of Cronartium spp.

Susceptibility of 18 alternate host species to Cronartium flaccidum or C. ribicola was tested. Alive test plants were inoculated in the greenhouse and the formation of Cronartium uredinia and telia was followed on the plants for 8 weeks. Cronartium flaccidum formed uredinia and telia on Bartsia alpina and Euphrasia stricta (Orobanchaceae), Nasa triphylla and N. urens (Loasaceae), Nemesia floribunda (Scrophulariaceae), Tropaeolum majus (Tropaeolaceae), Veronica daurica (Plantaginaceae) and Vincetoxicum hirundinaria (Apocynaceae). Single uredinia or telia developed also on N. urens and E. stricta inoculated with C. ribicola. For the first time, Cronartium are reported to sporulate on members of Loasaceae and Scrophulariaceae, N. urens and N. floribunda.     

The hosts and geographic range of Dothistroma needle blight in Slovakia

The occurrence and distribution of Dothistroma needle blight (DNB) were studied in 2014–2017 around Slovakia. A total of 84 localities, both native and planted, were investigated, and the presence of DNB was confirmed in 73 of them. In all positive locations, symptoms typical of DNB were observed and the Dothistroma species was confirmed using species‐specific primers either from fungal cultures or directly from needles. Both Dothistroma species—D. septosporum and D. pini—were identified. Both species occurred together in 29 locations, only D. septosporum in 42 and only D. pini in two locations. The host range of D. septosporum included 10 pine species and two spruce species. The host range of D. pini comprised the same number of pine hosts but only one spruce species. Five pine hosts, P. aristata, P. coulteri, P. densiflora, P. jeffreyi, P. × schwerinii, and one spruce host P. abies are new hosts species of D. pini. P. densiflora and Picea pungens have earlier been reported to be susceptible for DNB. In this study, D. septosporum was found from both tree species.     

The first record of Botryodiplodia canker in Poland

This study describes the first observation of Botryodiplodia canker in the Western Carpathians in south‐eastern Poland caused by Botryodiplodia hypodermia (Sacc.) Petr. (syn. Sphaeropsis hypodermia, S. ulmicola). The canker occurred on an approximately 17‐year‐old Ulmus glabra sapling in a mixed conifer/deciduous stand with elm trees severely damaged by Dutch elm disease. This paper describes disease symptoms and provides information on the macro‐ and micromorphology of the fungus isolated from the cankered tissues. The results of BLAST search using DNA sequences obtained for our cultures and subsequent phylogenetic positioning of the fungus among closely related Botryosphaeriaceae indicate that the species is much more closely related to Phaeobotryon than to the other Botryodiplodia or Sphaeropsis species. Moreover, a total of 16 polymorphisms within the ITS region were detected between S. ulmicola associated with Botryodiplodia canker in North America and B. hypodermia associated with the canker observed in Poland. Thus, the “European” variant of “Sphaeropsis” ulmicola can now be easily identified with our barcode sequences. The Botryodiplodia canker is much less prevalent in Europe than in North America. Differences in virulence of “American” and “European” linages and differences in susceptibility of various elm species may be the reason for the higher prevalence of the disease in North America.     

Die Bedeutung von Krankheitserregern beim gegenwärtigen Eichensterben in Europa – eine Literaturübersicht

The decline of oaks (Quercus spp.) has been reported in literature for more than two centuries. The symptoms of this syndrome seem to be the same at different sites - with the exception of oak with’ in North America, the geographic range of declines coincides more or less with the natural range of oaks, but most of the reports from the past few decades deal with the European situation and less With such syndromes in America and Asia. So far, the decline of oaks is not yet fully understood. Pathogens play’ a role as predisposing and aggravating factors, but in general are not the primary cause of the decline.     

Industrial air pollution and peroxidase activity in Scots pine needles – two case studies

The peroxidase activity (EC 1.11.1.7) in homogenates from Scots pine needles (Pinus sylvestries L.) were studied in relation to needle age and sampling locations around two different sources of industrial air pollution. Increased enzyme activity was associated with both increased needle age and proximity to the emission sources. Fluorine contamination in one of the cases was not correlated with enhanced enzyme activity. Enzyme activity levels were considered in relation to variations between trees and between different parts of the same trees.