The DIAROD Action will have four Working Groups to cover seven main tasks. These Working Groups will be expected to interact with each other to enable free flow of knowledge and ensure that all the tasks are fulfilled.
Working Group 1. The pathogen - defining the current disease situation
Leader and Deputy: Prof. Jan Stenlid (Sweden) and Dr Irene Barnes (South Africa).
Task 1: Distribution and severity of Dothistroma needle blight (DNB) in Europe - an integrated approach to defining the current disease situation
At present the distribution of D. septosporum and D. pini is not well understood at a European level. It appears that Dothistroma septosporum is abundant and widely distributed whereas D. pini appears to have a more limited geographical range. Furthermore it is not known whether the outbreaks of DNB in Ukraine and Russia are a result of D. pini alone or in combination with D. septosporum, as has been found in France and Hungary. EPPO No. 4 2009/068 recommends further studies to understand the geographical distribution and host range of both pathogens, and their respective role in the disease severity. This will be achieved through the consolidation of data from disease surveillance and monitoring in different European countries, and molecular diagnostics used to differentiate between the two Dothistroma species. The results on the distribution of these pathogens will be crucial for the implementation of European plant quarantine measures, i. e. by recognising parts of the continent where one or both pathogens are not present and where introduction should be avoided.
Task 2: Genetic Diversity of DNB in Europe - using pathogen population genetic diversity to infer origins and movement
Molecular tools will be used to determine the variation within populations of the two DNB pathogens in Europe. Generally, limited genetic variation in the population indicates a relatively recent introduction; conversely wide variation suggests a native pathogen or an exotic that has been present for a long time. The pathogen population structure needs to be understood before any conclusions about the biosecurity implications of forest pathogens can be drawn. Knowledge of the relatedness of the European population to those elsewhere in the world i.e. New Zealand, Canada, South Africa may provide an indication of the origins of DNB.
Working Group 2. The environment: determining the risk of DNB
Leader and Deputy: Prof. Julio J Diez Casero (Spain) and Lindsay Bulman (New Zealand).
Task 3: Influence of environment on DNB - studying environmental factors to understand present disease and predict future trends
For severe disease occurrence, certain conditions need to be met: high rainfall, moderate temperatures, suitable host material and sufficient inoculum to initiate infection. The interaction of these factors may explain recent outbreaks in Europe. Research is already underway in different parts of Europe to answer these questions. DIAROD will facilitate cross country collaboration, enabling cost savings in terms of time and resources whilst bringing together a comprehensive dataset. Data collected will be used to predict the impact of DNB under climate change in combination with different management strategies, in particular reduced plant density to decrease stand humidity and remove susceptible individual plants where appropriate.
Working Group 3. The host: resistance and susceptibility
Leader and Deputy: Dr Steve Woodward (UK) and Dr Rosie Bradshaw (New Zealand).
Task 4: Host resistance studies - applying cutting-edge research to understanding host resistance
Unlike some parts of the world, chemical control strategies for forest pathogens in Europe are not generally acceptable. Therefore, different approaches need to be considered. Although the optimum approach is to prevent new pathogens from establishing through stringent pathway management, this approach is not straight forward, particularly when multiple dispersal mechanisms are at play i.e. both human (movement of plants) and natural. Therefore, learning to live with pest outbreaks, and minimising the impacts on existing crops is essential. One method is through changing silviculture i.e. species choice and management regimes. However, research is also being done to investigate alternative methods of disease management that are focused on plant disease resistance. Firstly there have been exciting recent advances in understanding the stimulation of pine defence chemistries and physical defence properties that contribute to host-plant resistance. Secondly the recent discovery of conserved effector genes in the D. septosporum genome is anticipated to lead to deeper knowledge of genetic factors that contribute to resistance or susceptibility in the host plant. The Action will bring together the current state of knowledge of researchers involved in this area.
Task 5. Susceptibility of alternative hosts and apparent changes in susceptibility - development of practical advice regarding susceptibility of different host species
A question frequently posed by forest managers is ‘what can be planted when faced by the unavailability or unsuitability of a species due its devastation by a pest or pathogen’? This question is further complicated when the potential impacts of climate change are taken in to account. Furthermore, certain species such as Pinus sylvestris were previously considered to be of low susceptibility yet in the last two or three years the distribution and severity on this species has dramatically increased. The Action will assess the state of knowledge in this area through collation of data from field observations and in vitro and in vivo studies.
Working Group 4: Identifying research gaps and dissemination
Leader and Deputy: Dr Mike Hale (UK) and Dr Kath Tubby (UK)
Task 6: Identification of future research needs - ongoing evaluation of current research to identify further knowledge gaps
The past meetings of the IDA focussed on immediate research needs. The research proposed in Tasks 1 to 5, and the sharing of this information as a result of DIAROD will identify further knowledge gaps and direct future research programmes, providing “best value for money” through increased collaborative research, sharing both ideas and resources.
Task 7: Dissemination of results - ensuring rapid knowledge transfer to stakeholders and other interested parties
The dissemination routes proposed by DIAROD will include annual workshops with basic proceedings. The DIAROD website and attendance at general plant pathology meetings (i.e. IUFRO, ICPP) will provide mechanisms to promote the activities and findings of DIAROD. Furthermore, a final paper will be produced outlining the conclusions regarding the biosecurity implications and risks of the changing dynamics of DNB, both now and under future climate and management scenarios. A best practice guide, based on the application of simple principles will also be produced for practitioners.