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Rees R.W.,University of Bath | Flood J.,CABI Europe UK | Hasan Y.,Bah Lias Research Station | Wills M.A.,University of Bath | Cooper R.M.,University of Bath
Plant Pathology | Year: 2012

Basidiospores are implicated in the distribution and genetic diversity of Ganoderma boninense, cause of basal stem rot (BSR) and upper stem rot (USR) of oil palm (Elaeis guineensis). Measurement of aerial basidiospores within plantations in Sumatra showed continuous and high production over 24h (range c. 2-11000sporesm -3) with maximum release during early evening. Basidiospores applied to cut surfaces of fronds, peduncles and stems germinated in situ. Equivalent, extensive wounds are created during plantation harvesting and management and represent potential sites for formation of infective heterokaryons following mating of haploid basidiospore germlings. Use of spore-sized micro-beads showed that basidiospores could be pulled up to 10cm into severed xylem vessels, where they are relatively protected from dehydration, UV irradiation and competing microflora. Diversity of isolates from five locations on two plantations was assessed by RAMS fingerprinting. Isolates from within individual palms with USR were identical and represent single infections, but different USR infections had unique band patterns and revealed separate infections. Some BSR-affected trees contained more than one isolate, and thus had multiple infections. There was one example of adjacent BSR palms with the same isolate, indicating vegetative spread, but there were no identical genets from BSR infections and adjacent fallen palms. Isolate diversity was as great within a plantation as between plantations. It is evident that basidiospores play a major role in spread and genetic variability of G. boninense. Evidence for direct basidiospore infection via cut fronds, indirectly through roots via colonized debris and less frequently, infection by vegetative, clonal spread is considered. © 2011 University of Bath. Plant Pathology © 2011 BSPP.


Day M.D.,Fisheries and Forestry | Kawi A.P.,National Agricultural Research Institute | Ellison C.A.,CABI Europe UK
Biological Control | Year: 2013

The rust fungus Puccinia spegazzinii was introduced into Papua New Guinea (PNG) in 2008 as a classical biological control agent of the invasive weed Mikania micrantha (Asteraceae), following its earlier release in India, mainland China and Taiwan. Prior to implementing field releases in PNG, assessments were conducted to determine the most suitable rust pathotype for the country, potential for damage to non-target species, most efficient culturing method and potential impact to M. micrantha. The pathotype from eastern Ecuador was selected from the seven pathotypes tested, since all the plant populations evaluated from PNG were highly susceptible to it. None of the 11 plant species (representing eight families) tested to confirm host specificity showed symptoms of infection, supporting previous host range determination. A method of mass-producing inoculum of the rust fungus, using a simple technology which can be readily replicated in other countries, was developed. Comparative growth trials over one rust generation showed that M. micrantha plants infected with the rust generally had both lower growth rates and lower final dry weights, and produced fewer nodes than uninfected plants. There were significant correlations between the number of pustules and (a) the growth rate, (b) number of new nodes and (c) final total dry weight of single-stemmed plants placed in open sunlight and between the number of pustules and number of new nodes of multi-stemmed plants placed under cocoa trees. The trials suggest that field densities of M. micrantha could be reduced if the rust populations are sufficiently high. © 2013.


Gerber E.,CABI Europe Switzerland | Schaffner U.,CABI Europe Switzerland | Gassmann A.,CABI Europe Switzerland | Hinz H.L.,CABI Europe Switzerland | And 2 more authors.
Weed Research | Year: 2011

The recent invasion by Ambrosia artemisiifolia (common ragweed) has, like no other plant, raised the awareness of invasive plants in Europe. The main concerns regarding this plant are that it produces a large amount of highly allergenic pollen that causes high rates of sensitisation among humans, but also A. artemisiifolia is increasingly becoming a major weed in agriculture. Recently, chemical and mechanical control methods have been developed and partially implemented in Europe, but sustainable control strategies to mitigate its spread into areas not yet invaded and to reduce its abundance in badly infested areas are lacking. One management tool, not yet implemented in Europe but successfully applied in Australia, is biological control. Almost all natural enemies that have colonised A. artemisiifolia in Europe are polyphagous and cause little damage, rendering them unsuitable for a system management approach. Two fungal pathogens have been reported to adversely impact A. artemisiifolia in the introduced range, but their biology makes them unsuitable for mass production and application as a mycoherbicide. In the native range of A. artemisiifolia, on the other hand, a number of herbivores and pathogens associated with this plant have a very narrow host range and reduce pollen and seed production, the stage most sensitive for long-term population management of this winter annual. We discuss and propose a prioritisation of these biological control candidates for a classical or inundative biological control approach against A. artemisiifolia in Europe, capitalising on past experiences from North America, Asia and Australia. © 2011 The Authors. Weed Research © 2011 European Weed Research Society.


Taylor B.,CABI Europe UK | Rahman P.M.,Kerala Forest Research Institute KFRI | Murphy S.T.,CABI Europe UK | Sudheendrakumar V.V.,Kerala Forest Research Institute KFRI
Experimental and Applied Acarology | Year: 2012

Field surveys were conducted monthly between December 2008 and July 2009 in Kerala, south-west India to compare the population dynamics of the red palm mite Raoiella indica (RPM) on two host plants Areca catechu and Cocos nucifera during one non-monsoon season when, in general, RPM populations increase. The aim was to examine the effects of host plant, host plant locality and the impact of climatic factors on RPM and related phytoseiid predators. There were significantly higher RPM densities on areca in peak season (May/June) compared to coconut; although significantly more coconut sites were infested with RPM than areca. Although no one climatic factor was significantly related to RPM numbers, interactions were found between temperature, humidity and rainfall and the partitioning of host plant locality showed that where conditions were warmer and drier, RPM densities were significantly higher. Specifically on coconut, there was a significant relation between RPM densities and the combined interaction between site temperature, site humidity and phytoseiid densities. There was a marked difference in the density of phytoseiids collected between areca and coconut palms, with significantly more on the latter, in several months. Amblyseius largoensis was the most commonly collected phytoseiid in association with RPM, although Amblyseius tamatavensis species group and Amblyseius largoensis species group were collected in association with RPM also. There was also evidence of a weak numerical response of the combined phytoseiid complex in relation to RPM density the previous month on coconut but this was not observed on areca. © 2011 Springer Science+Business Media B.V.


Bridge P.D.,CABI Europe UK | Spooner B.M.,Mycology Section
Fungal Ecology | Year: 2012

To date over 1 000 non-lichenized fungal species have been recorded by collection or isolation from Antarctica, and additional taxa are now being identified by molecular studies. The number and variety of species recorded so far suggest that the fungi may be the most diverse biota in the Antarctic, and the additional taxa identified by molecular surveys suggest that the true diversity may be far greater than is currently estimated. Fungi occupy many different ecological niches in the Antarctic, and their significance in these niches is only poorly understood. The majority of species described from the region have been identified as members of broadly cosmopolitan groups, but there is some evidence for both endemic strains and populations. This review brings together the current broad systematic and ecological findings for the non-lichenized Antarctic fungi. © 2012.


Damm U.,Fungal Biodiversity Center | Cannon P.F.,CABI Europe UK | Woudenberg J.H.C.,Fungal Biodiversity Center | Johnston P.R.,Landcare Research | And 6 more authors.
Studies in Mycology | Year: 2012

Although only recently described, Colletotrichum boninense is well established in literature as an anthracnose pathogen or endophyte of a diverse range of host plants worldwide. It is especially prominent on members of Amaryllidaceae, Orchidaceae, Proteaceae and Solanaceae. Reports from literature and preliminary studies using ITS sequence data indicated that C. boninense represents a species complex. A multilocus molecular phylogenetic analysis (ITS, ACT, TUB2, CHS-1, GAPDH, HIS3, CAL) of 86 strains previously identified as C. boninense and other related strains revealed 18 clades. These clades are recognised here as separate species, including C. boninense s. str., C. hippeastri, C. karstii and 12 previously undescribed species, C. annellatum, C. beeveri, C. brassicicola, C. brasiliense, C. colombiense, C. constrictum, C. cymbidiicola, C. dacrycarpi, C. novae-zelandiae, C. oncidii, C. parsonsiae and C. torulosum. Seven of the new species are only known from New Zealand, perhaps reflecting a sampling bias. The new combination C. phyllanthi was made, and C. dracaenae Petch was epitypified and the name replaced with C. petchii. Typical for species of the C. boninense species complex are the conidiogenous cells with rather prominent periclinal thickening that also sometimes extend to form a new conidiogenous locus or annellations as well as conidia that have a prominent basal scar. Many species in the C. boninense complex form teleomorphs in culture. © CBS-KNAW Fungal Biodiversity Centre.


Cannon P.F.,CABI Europe UK | Damm U.,Fungal Biodiversity Center | Johnston P.R.,Landcare Research | Weir B.S.,Landcare Research
Studies in Mycology | Year: 2012

A review is provided of the current state of understanding of Colletotrichum systematics, focusing on species-level data and the major clades. The taxonomic placement of the genus is discussed, and the evolution of our approach to species concepts and anamorph-teleomorph relationships is described. The application of multilocus technologies to phylogenetic analysis of Colletotrichum is reviewed, and selection of potential genes/loci for barcoding purposes is discussed. Host specificity and its relation to speciation and taxonomy is briefly addressed. A short review is presented of the current status of classification of the species clusters that are currently without comprehensive multilocus analyses, emphasising the orbiculare and destructivum aggregates. The future for Colletotrichum biology will be reliant on consensus classification and robust identification tools. In support of these goals, a Subcommission on Colletotrichum has been formed under the auspices of the International Commission on Taxonomy of Fungi, which will administer a carefully curated barcode database for sequence-based identification of species within the BioloMICS web environment. © CBS-KNAW Fungal Biodiversity Centre.


Shaw R.H.,CABI Europe UK | Tanner R.,CABI Europe UK | Djeddour D.,CABI Europe UK | Cortat G.,CABI Europe UK
Weed Research | Year: 2011

The programme for the biological control of Fallopia japonica in the United Kingdom has provided some valuable insights into the practicalities of delivering a classical biological control programme against a weed in the European Union. In the absence of tailored legislation, the licensing process was complex but not prohibitive. It involved the production of a pest risk analysis (PRA; based on the EPPO template), an application through national legislation (the UK Wildlife and Countryside Act), the production of peer-reviewed publications, expert committee consideration, further commissioned peer review and public consultations prior to final Ministerial judgement, which was granted in March 2010. Although there is room for some streamlining in the process, this approach has proved to be effective and robust and should be applicable to similar programmes in Europe. This is important, because classical biological control has considerable potential for the management of F. japonica and other weed targets throughout Europe, especially those impacting habitats where chemical use is all but impossible. The lessons learned from the knotweed biocontrol programme are discussed, and current weed biocontrol activities in Europe are briefly summarised. A classical biocontrol programme needs to deliver more than just pure science, because effective communication and negotiations in the public and political arena can provide more challenges than the traditional scientific ones. © 2011 The Authors. Weed Research © 2011 European Weed Research Society.


Damm U.,Fungal Biodiversity Center | Cannon P.F.,CABI Europe UK | Woudenberg J.H.C.,Fungal Biodiversity Center | Crous P.W.,Fungal Biodiversity Center | And 2 more authors.
Studies in Mycology | Year: 2012

Colletotrichum acutatum is known as an important anthracnose pathogen of a wide range of host plants worldwide. Numerous studies have reported subgroups within the C. acutatum species complex. Multilocus molecular phylogenetic analysis (ITS, ACT, TUB2, CHS-1, GAPDH, HIS3) of 331 strains previously identified as C. acutatum and other related taxa, including strains from numerous hosts with wide geographic distributions, confirmed the molecular groups previously recognised and identified a series of novel taxa. Thirty-one species are accepted, of which 21 have not previously been recognised. Colletotrichum orchidophilum clusters basal to the C. acutatum species complex. There is a high phenotypic diversity within this complex, and some of the species appear to have preferences to specific hosts or geographical regions. Others appear to be plurivorous and are present in multiple regions. In this study, only C. salicis and C. rhombiforme formed sexual morphs in culture, although sexual morphs have been described from other taxa (especially as laboratory crosses), and there is evidence of hybridisation between different species. One species with similar morphology to C. acutatum but not belonging to this species complex was also described here as new, namely C. pseudoacutatum. © CBS-KNAW Fungal Biodiversity Centre.


Summary - Additional information on Rhigonema brevicollum, the type of the genus Rhigonema, and on Heth juli, the type of the genus Heth, is presented based on original, hitherto unpublished, descriptions held in the Cobb Archive at the USDA, Beltsville, MD, USA. Both species were originally published as small annotated illustrations in a general work, although the promised full descriptions were never published by Cobb. The genus Rhigonema is shown to be based on a species lacking a vaginal diverticulum in the female genital system, but having a long, Type 2, ovejector. The genus Dudekemia, originally differentiated from Rhigonema on an assumed (and erroneous) difference in female genital tract form, is confirmed as a junior synonym of Rhigonema. A full description of both sexes of Heth juli is also provided, again based on Cobb's original notes, thereby defining the type species with greater precision than was previously possible. © Koninklijke Brill NV, Leiden, 2015.

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