BSPP News Autumn 2000 - Online EditionThe Newsletter of the British Society for Plant Pathology
Number 37, Autumn 2000
People and Places
Cambridge Mycology and Plant Pathology Club
Two meetings were held in the Lent Term. On Friday, 11 February 2000, David Leaper of Monsanto plc presented a comprehensive review entitled 'Management of take-all – new opportunities'. The stimulus for the work was the discovery of new fungicide silthiophan which showed remarkable specificity for the take-all fungus. It was still under development in the UK as a seed treatment which typically gave about 80% control of take-all early in the season with 40-50% reduction at grain filling. Reductions in the number of whiteheads averaged 60%. A large number of replicated field experiments in the UK and other EU countries showed that yield responses to the seed treatment were related to take-all severity and averaged 0.9 t/ha under high take-all infection. The seed treatment would not overcome take-all problems on its own and greater emphasis would need to be placed on risk assessment and manipulation of agronomic factors if improved take-all management was to be achieved. The results of over 300 experiments had been collated to improve risk assessment in relation to previous cropping, sowing date, soil type and future weather. The addition of a new component in take-all management is eagerly awaited but approval has still be given for this use in the UK.
'Potato scabs, scurfs, dots and spots' was the theme of David Firman of Cambridge University Farm on Friday, 25 February. Quality is now of paramount importance for potato growers and blemish diseases are more important than all the rotting diseases except late blight. Tissue culture and minituber techniques had initially been seen as a means of controlling diseases but in practice stocks quickly became re-infected. The symptoms and factors affecting the major blemish diseases were outlined. Silver scurf had become important since pre-packing started, whilst black dot appeared to have increased in importance over the last 5 years (regrettably there was no long term survey data to prove this). Common scab could be controlled to a large extent using irrigation though this might have a detrimental effect on other diseases. Integrated control using cultivar, seed health, fungicidal seed treatments, length of the growing season and careful management in storage was being practised, but there was still much to learn about the spread and development of these pathogens.
Scottish Agricultural Colleges
There are three centres of study at SAC: Auchincruive on the west coast, Aberdeen in the north and Edinburgh on the east. Plant Pathologists work at all three sites and recent restructuring at SAC means that we are now united in one large division of 'Plant and Crop Science'. Not that we didn't speak before, but it all helps!
Over at Auchincruive, Dale Walters, Billy Sinclair, Tracy Cowley and Arlene McPherson have recently started a new programme of work on oilseed rape. There are two aspects to the work. The first involves characterising oxylipins in interactions between oilseed rape and the following pathogens: Peronospora parasitica, Pyrenopeziza brassicae and Alternaria brassicicola. Part of this programme will involve genetic manipulation of the oxylipin profile in oilseed rape and determining the effects on resistance or susceptibility to infection. This part of the work involves close collaboration with Ted Farmer's group at the University of Lausanne. The second aspect of the work involves studies of gene expression in interactions between oilseed rape and the pathogens mentioned above.
Tracy Cowley and Dale Walters visited Ted Farmer's lab in Lausanne recently to talk about oxylipins and to discuss links. Tracy spent some time there perfecting techniques for accurate and reliable analysis of oxylipins. Dale Walters has just been conferred with the title Professor of Biochemical Plant Pathology at the SAC awards ceremony in July.
Celia Fox runs the Crop Health Centre at Auchincruive, dealing mainly in the diseases and problems of hardy ornamental stock. She has recently positively identified Dutch Elm Disease on the west coast. Although it has been about in the east of Scotland and the Glasgow areas for a while, it has only just made its presence known there. The pathogen is 'Ceratocystis ulmi', carried by the elm bark beetle (Sclolytus spp.) The fungus grew very quickly on PDES.
SAC Aberdeen hosted an EU powdery scab workshop 20-22 July for 17 research scientists and 4 agronomists. Countries represented were England, Scotland, Denmark, Ireland, France, Holland and Switzerland, with a guest appearance from Australia. The aim of the workshop was to examine all aspects of this potato disease, to look for commonality of approach to identification and quantification and aspects relating to seed certification. Such is the interest in this disease that Stuart Wale is spending most of August in Australia and New Zealand talking to growers there about powdery scab. Also on potatoes, Rob Clayton has several projects looking at the interactions of the potato storage diseases including silver scurf, skin spot, gangrene and dry rot with store micro-climate. He is also involved in a project examining store hygiene as a method of reducing contamination from any pathogen. It's not all potatoes in Aberdeen and Karene Sutherland keeps cereal and oilseed rape pathology active, with projects on leaf spot of oilseed rape and trials on the efficacy of cereal fungicides.
In Edinburgh we have a 'new' cereal disease to keep us occupied in the Crop Health Section. Spotting on the leaves of spring barley has been a problem for Scottish growers for a number of years and in the last four seasons it has become much worse so that many crops die off prematurely threatening both yield and quality. In collaboration with researchers from Ireland, Austria, Norway, Germany and New Zealand, we have started work on a project investigating the fungus Ramularia collo-cygni
Participants at the Ramularia workshop
Simon Oxley is leading this work and we now know that this fungus is the cause of some but not all of the spotting. Other suspects include sun scorch and pollution, and varietal characteristics also play a part. The pattern of the disease is very strange. The barley is healthy until the awns or heads have emerged and then the upper two leaves are rapidly overtaken with the spotting symptoms. The lower leaves remain less affected. There is definitely a weather interaction as shading experiments drastically reduce the symptoms seen. The countries where the disease occurs all have a wet and cool climate. Sudden bursts of sunshine in a wet summer seem to make the symptoms worse. We can reduce the disease with fungicides but we don't know now whether this actually makes things worse in the end by clearing other pathogens from the leaf. Neil Havis is working on a project to prepare a probe so that we can test for the disease and be more categorical about which symptoms are caused by Ramularia and which are not.
After years out of the limelight, fungicide resistance is now a hot topic with growers and agrochemical companies, with the emergence of strobilurin resistant mildew. Fiona Burnett is involved in several projects looking into the distribution of the resistant mildew and trying to establish the risk factors that make its occurrence more likely. Resistance to triazole fungicides in Rhynchosporium is another area being researched. Simon Oxley has a project looking at varietal resistance and methods of controlling this disease. There are concerns that triazole resistance is now widespread in Scotland and their use in barley is being questioned.
As well as their research projects the Crop Health Section also runs a Crop Clinic and offers advice to growers and trials services to agrochemical companies. It has been hard work holding on to this business in the current agricultural decline and it has been a great sadness to see many long standing clients leave the industry.
Another project that is just starting in Edinburgh is looking at the stem base disease eyespot. Gareth Hughes aims to develop a mathematical model which will allow growers to attach a risk factor to the various factors which influence the development of eyespot such as sowing date, variety and cultivation method. Tapesia acuformis is now the dominant eyespot species in the UK and we suspect this is why the threshold approach to deciding if a crop merited treatment for eyespot no longer works. The model should enable growers to make cost effective decisions on whether a specific eyespot fungicide is merited on a crop.
Staff in the Biotechnology Section in Edinburgh with significant plant pathology research interests include Bill Spoor, Felix D'Mello, Mark Hocart, Rob Harling, Lucy Harrier, Armelle Gollotte and David Walsh. Other staff have teaching and advisory roles. In addition, the section comprises a number of postgraduate research students and a regular turn-over of visiting researchers and research students.
The research interests in this part of the Plant and Crop Science Division involve the investigation of diversity and interactions between plants and other organisms. One of their main areas of interest is the interaction between plants and arbuscular mychorizhal fungi. Projects include: the identification of plant and fungal genes specifically expressed during the symbiotic interaction, gene expression associated with modification of the plant cell cycle during the symbiotic association, mycorrhizal interactions with root infecting plant pathogenic fungi, and the use of reporter gene systems to study symbiotic interactions at the level of gene expression in the plant root.
Diversity studies include: the development and use of techniques to determine and quantify the level of biodiversity in arbuscular mycorrhizal fungi in managed and unmanaged plant communities, the genetic diversity of foliar pathogens associated with culinary and industrial varieties of oilseed rape, and the genetic diversity of barley landraces. Recently, work on barley has focused on investigating how genetic diversity contributes to the productivity and characteristics of barley crops, with the objective of identifying characteristics that can be used to deploy genetic diversity more effectively in low chemical input crop production systems. Pesticide-related effects on the production of fusarium mycotoxins is the current focus of the mycotoxin work of the section.
Lastly, work on the behaviour of phylloplane bacteria in disease aetiology in broccoli spear rot has led to a research programme on the role of biosurfactants in phylloplane microbiology and disease development and also to applications for biological control.On the advisory side the section supplies advisory pathology for farmers and growers and has been involved in helping to set up local crop clinics and extension support in south-east Asia.
The latest issue of the ISPP Newsletter is now available online at: http://www.isppweb.org/nlaug00.htm
Horticulture Research International
18th International Fruit Virus Conference
HRI East Malling have just
hosted the 18th International Fruit Virus Conference, 10th - 15th July
at UKC Canterbury.There were
approximately 110 delegates from a wide range of countries. Most east and
west European countries were represented, as well as the US, Canada, Australia
and Chile. The convenor was Michael Clark. Other members of the local organising
committee were: Tony Adams, David Davies, Chris Guise, Sarah Loat, Jean
Hodges and Carole Quinlan. Rosemary Clark and Peter Walters organised the
accompanying persons programme.
Delegates at the 18th International Fruit Virus Conference
The symposium was opened by Rt. Hon L Mayhew of Twysden QC, Chairman of the British Parliamentary Fruit Industry Group, and by Dr Alwyn Thompson, Deputy Chief Executive of HRI. Opening speakers were Professor Michael Thresh (NRI) and Professor Michael Wilson (Chief Executive, HRI). There were four winners of the Posnette award. These were: Tony Adams (HRI, UK), Jean-Claude Desvignes (France), Thierry Candresse (INRA, France) and Maria Kolber (Hungary). The awards were presented by Mike Thresh at the symposium dinner which was held at Leeds Castle, Thursday evening.
Also included was an excursion to HRI East Malling on Wednesday morning. After a brief welcome by Alwyn Thompson, delegates were given brief presentations in the field by Colin Campbell, Tony Adams, Katherine Philips, Ken Tobutt and Vicky Knight. There then followed a buffet lunch provided by the Trustees at Bradbourne House, where the group photograph was taken. An award winning beer brewed by Adnams containing First Gold hops (a dwarf variety bred by HRI) was also provided. This was a pretty heady brew - 6.3% abv!
David Davies organised a joint progress meeting at Canterbury on the 9th July of two EU projects on virus and virus like pathogens of pome fruit, stone fruit and strawberries. The two projects are coded FAIR3889 (in its final year) and QLK5 1553 (in its first year).
A formal link has been created with Aberdeen University for work on the detection of Verticillium dahliae (Dez Barbara). New HDC projects include sources survival and disinfection of pepino mosaic virus, a new virus in tomato, with scientists at HRI (Nicola Spence), CSL and ADAS; detection of a novel mushroom virus (Helen Grogan and Mike Challen); salad onions: control of white rot (Carol Paterson); Lisianthus: Control of downy mildew (Pernospora chlorae) (Andrew Jackson and Martin McPherson).
An application for an EU Framework Programme V project on modelling and forecasting Fusarium ear blight and the associated mycotoxins was successful (David Parry and Xiangming Xu). The East Malling Trust have funded a new project on developing and evaluating a warning system for strawberry grey mould (Angela Berrie ). Yiguo Hong and Angela Berrie were awarded the Blackman studentship on mycovirus in Nectria galligena by East Malling Trustees.
HRI International Activities
John Walsh presented a paper entitled "Serological detection and quantification of Olpidium brassicae, an important virus vector" at the Fourth Symposium of the International Working Group of Plant Viruses with Fungal Vectors (IWGPVFV) in Monterey, California (5-8 October). Peter Mills presented a paper at the 15th International Congress on the Science and Cultivation of Edible Fungi, Maastricht. Two PhD students from Uganda have recently started an 8-month visit to develop molecular diagnostic techniques for the differentiation of Fusarium and Pythium species which contribute to the bean root rot disease complex in Africa. They are part of a DFID-funded project and are working with John Carder, Geoff White, Tim Pettitt, Peter Mills and Nicola Spence.
Alison Wakeham presented a paper at the EPPO Diagnostics meeting in Wageningen, February 2000.
Andy Jackson and Martin McPherson presented two posters at the XIIth International Botrytis Conference in Reims (3-6 July) on the development of integrated disease control programs for the control of Botrytis on lettuce and cucumber. Tom Vets an exchange student in Horticulture from Belgium is working with Andy Jackson at Stockbridge House on an EU project looking at microbial suppression and disinfection techniques in recirculation hydroponic systems.
Commercial and Knowledge Transfer
The Plant Clinic at Stockbridge House (run by Cheryl Brewster) continues to increase steadily the number of samples, including extensive screening for levels of bacteria contamination in cut flowers for a major flower producer. The carrot cavity spot soil test has been re-instated during the winter of 1999/2000 with advertising and reporting on the service being dealt with through Stockbridge House. HortiTech Diagnostic Services launched the DeTechtor pathogen detection kits at Hortex. Two formats have been designed either based on lateral flow technology or slide agglutination tests. Initially, DeTechtor kits for over 20 bacterial and viral pathogens are available. Nigel Lyons ran a workshop on pathogen detection for the ARIA Science day at Rothamsted.
Plant Clinic services, offered through HortiTech, have launched a new laboratory test for the detection of Pythium and Phytophthora in water samples and around the nursery. Additional tests for Verticillium spp. in soil samples and for onion storage soft rots diseases have been launched.
University College, London
The academic year started well with two students obtaining their Ph.Ds. The title of Khalid Hamid's thesis was "Separation and phytotoxicity of solanapyrone compounds produced by Ascochyta rabiei (Pass.) Labr. and their metabolism by chickpea (Cicer arietinum)". He has now returned to a post at Ayub Agricultural Research Institute, Faisalabad, Pakistan. Preprame Pattanamahakul has returned to Thailand where she has secured a lectureship at Chulalongkorn University, Bangkok. Her thesis "Identification and toxigenicity of Alternaria brassisicola, the causal agent of dark leaf spot of Brassica species grown in Thailand" was considered so exemplary by her examiners that not even a single minor correction was required!
I have just concluded some rather long negotiations with the EU concerning a grant proposal I submitted last September. The project is concerned with the development of integrated pest management techniques for the control of Ascochyta blight of chickpea and involves a laboratory in Cordoba, Spain, two laboratories in Tunis and two in Ankara, Turkey. Besides work in the fields and laboratories of these countries, the grant of 736,804 Euros will support two students at UCL who will be tackling the more fundamental aspects of the interaction of the pathogen and its host.
I am also looking forward
to Jane Hollywood joining the laboratory on a Perry Foundation Award. She
will be following up some preliminary work on the biocontrol of potato
blight, which was reported by Elinor Thompson at the BSPP meeting last
Temitope Aiyere joined the laboratory this year and is investigating the polymorphism and host specificity of Colletotrichum species with special emphasis on isolates obtained from yams, an important crop in her home country, Nigeria. This research is being carried out in co-operation with Jeff Peters of Reading University.
I am three-quarters of the way through updating my book, which this time will probably have a different title and will be aimed specifically at the undergraduate market. I have persuaded the potential publisher of the need for colour pictures so if any one has a particularly attractive and informative photograph of something relevant to the teaching of plant pathology, I shall be glad to hear from them - e-mail address firstname.lastname@example.org!
Central Science Laboratory
Since the last episode of selected highlights of CSL's Plant Health Group activity up to February this year, there has been much water under the bridge (York has witnesssed some extraodinary flooding on the River Ouse!). Joking apart, Nigel Hardwick's Crop Disease Research Team continues to be involved in a wide-range of activities. Nigel organised the CSL input into the national 'Cereals 2000'event held on 14 and 15 June at Nocton, a few miles south east of Lincoln. It is the UK's leading arable event, attracting over 13,500 visitors and 260 exhibitors. Demonstrating the CSL "Pocket Diagnostics" virus test kits were Chris Danks and John Banks from Ian Barker's Team. Alternative crops were on display and one of them, fibre hemp (Cannabis sativa), created a lot of interest, particularly from visiting students who couldn't resist having a sniff. Hemp used for fibre is low in tetrahydrocannabinol (0.3%), so a whole field would have to be smoked to get a 'high'! However, the team were instructed by the Drugs Squad Officer from the Lincolnshire Constabulary to remove the plants at night to a secured van - we "counted them out" and "counted them back in". Richard Leach and Jackie Stonehouse from Nigel's Team were responsible for the plots. Phil Jennings was present at the HGCA plots with Paul Nicholson of the John Innes Centre, Mike Nuttall of Morley Research Centre and Peter Jenkinson of Harper Adams College demonstrating the control of fusarium ear blight.
Nigel Hardwick was also involved
with the 'Active Learning Centre' at the Great Yorkshire Show (11-13 July)
in Harrogate. This was an initiative by the Yorkshire Agriculture
Society to involve local schools and an industrial partner in providing
'hands-on' experience of industry. CSL was teamed up with three students
from Rossett School, Harrogate. The purpose of the event was to show
how practical activities promote learning across various aspects of an
important food crop - cereals. The theme of the event was 'Cereal
Crops and their Products'. CSL covered aspects of pest and disease
control in cereals - the cost impact on the industry due to disease and
the importance of preserving beneficial insects in field margins.
The challenge for the students was to put across complex messages to visitors
ranging from primary school children to university professors. The
former was the more difficult! The presence of aphid-eating ladybirds
helped. One unplanned task was to remove camouflage face paint from
the eyepieces of the microscopes left by those pupils who had previously
visited the army exhibit. The team were rather embarrassed when one
mother noticed that when her young daughter got up from viewing the ladybirds
she had taken on the appearance of a wide-eyed owl!
Phil Jennings attended the second meeting of the EU concerted action PL98-4094 on "Quality control measures in the production and processing chain to reduce Fusarium mycotoxin contamination of food and feed grains". The meeting was held in Paris between 30 March and 1 April 2000. The overall objective of this Concerted Action is to establish a working relationship at the European level between all the partners of the production chain of cereal based food and feed products, to be able to reduce or even prevent mycotoxin contamination due to fusarium fungi in cereal based food and feed production by means of an effective collaboration. The CSL involvement in this "cluster" of projects brings together the epidemiological expertise from Phil with the mycotoxin, mycology and immunological expertise of John Banks.
Nigel Hardwick was awarded
the Huxley Memorial Medal for 1999 by Imperial College, London. The
medal, established in 1990, is awarded to a student or former student for
achievement in a branch of the natural science in which Thomas Huxley was
distinguished. Nigel Hardwick was at Imperial College from 1963-1969
from where he obtained both his BSc and PhD.
New Disease Reports; the new on-line BSPP journal (Senior Editor Claire Sansford) has proved successful, attracting 15 submissions to date from around the world, 11 of which made it to the July deadline for publication in Plant Pathology, December 2000.
Claire attended a "Kick-off meeting" for Co-ordinators successful under the first call of the EC Fifth Framework Programme in Brussels on 31 March 2000. As a first-time Co-ordinator of an EC Project ("Karnal bunt risks") the benefits of attendance included further familiarisation with the Co-ordinator's role and that of the staff of the EC. In addition to gaining an EC perspective into the process of proposal submission through to success, it was also useful to hear the statistics of numbers of submissions, successful Projects and their size and value. A public website managed by our Norwegian partner, Dr Haakon Magnus of NCRI, Fellesbygget was successfully launched in August 2000. (http://www.planteforsk.no/prosjekter/karnalpublic/index.htm).
A trip made by Claire to the WTO Headquarters in Geneva on 19 – 22 June, firstly to a Workshop on Risk Analysis for Developing Countries attended by ca. 150 delegates proved fascinating, as did the opportunity to attend one day of the WTO Sanitary and Phytosanitary Committee Meeting where real-live trade disputes were aired in an extremely civilised fashion. This could only be described as a finals match at Wimbledon!
Last but not least, the stork has been busy again in Plant Health Group. Judith Turner returned to the fold after a spell of maternity leave. Congratulations to Judith and Miles Thomas on the birth of Matthew.