This concept of the GILB management structure therefore follows the pattern of research consortia already developed within the CGIAR and at CIP, such as CONDESAN.

The meeting was asked to support the concept of identifying three persons as an initial steering committee, which would then identify three other members to form the full group. Suggestions are now being sought by CIP. At present, G.R. Mackay is acting as GILB Coordinator at CIP, supported by Dr. Ed French and by fellow directors and colleagues at CIP.

 

 

Summaries of Presentations at the Twenty-fifth Anniversary Symposium,

March 18, 1996

Welcome. Hubert Zandstra, Director General, CIP.

Potato late blight disease is public enemy number one for farmers and consumers around the world. In order to defeat this crop killer, CIP organized this project design meeting to prepare a global initiative on late blight. We are pleased to welcome 41 guests who are experts on late blight from 16 countries plus 15 CIP scientists and administrators.

Although the real value of support to potato research in the CGIAR has declined by nearly 40% since 1987, CIP has increased its input into research on late blight. We believe that the CGIAR needs to adjust priorities for potato and late blight, with more recognition being given to the growth potential of potato production. Its yield potential should be more clearly reflected in priorities. Since potato production in developing countries has been increasing by 3.6% per year since 1961 and late blight has become a much more serious threat, we are therefore asking the CGIAR's Technical Advisory Committee to increase priority for potato, and to use that allocation for late blight. We request your support for this initiative.

George Mackay, CIP Director of Genetic Resources, will serve as coordinator in the crucial start-up phase of the global initiative. I thank Edward French, CIP's program leader for disease management, for organizing this meeting. I challenge participants to collect information across the major potato producing ecosystems and identify for each, specific needs for additional research on late blight. I would like to paraphrase a statement by Lowell Hardin, one of the founders of the CGIAR and professor emeritus at Purdue University, commenting upon this gathering. "It seems to me that, in addressing a global problem of major magnitude, CIP is doing just what an international center was created to accomplish. CIP's comparative advantage is in dealing with issues that transcend national and political boundaries. The pathogen that causes late blight knows no geographic limitations. Thus, while much of the essential work must be done in each potato-producing country, CIP can bring a synergism to this effort that would otherwise be unlikely to occur."

It is now up to all of us to follow through as a team.

Looking Ahead after 25 years of Progress at CIP.

Richard L. Sawyer, Founding Director General of CIP.

Richard Sawyer, Founding Director General of CIP, gave a brief history of the Center and summarized its achievements. Sawyer highlighted CIP´s excellent financial management during difficult times. He addressed research and began by mentioning the importance of establishing cleanup procedures to obtain germplasm of sufficient quality for export.

Achievements were multiple: work in biotechnology and tissue culture, experiment stations, an international board of trustees, outreach stations around the world to serve developing countries, research contracts, an international staff, incorporating anthropologists to focus on users of technology, and international planning conferences. "CIP has distributed materials, held symposia, served countries, and trained scientists," Sawyer said.

He added, "We have had good credibility with donors in managing finances, and our credibility in germplasm cleanup and distribution is well known. When in the late 1970s China opened its doors, CIP was the first center to set up a regional office."

Sawyer highlighted CIP´s bottom-up approach—looking at technology from a user´s viewpoint. He also mentioned the importance of teamwork and the multidisciplinary approach. He reviewed the incorporation of sweetpotato into CIP´s research agenda and the Andean natural resource management program.

In his look ahead, Sawyer stressed the importance of potato as a world food: "Under intensive potato production, more gains are possible for potato than for cereals." He mentioned the need for global promotion of potato and the importance of moving local potato varieties into fast-food chains, which are currently dependent on imports.

Sawyer concluded his talk with several recommendations: "CIP should concentrate on a global approach, focus on users, obtain private-sector support, associate fast-food chains with research, maintain a team of host-country support staff, and communicate the value of what the Center does to the general public."

A Century and a Half Late Blight Pandemic.

John Niederhauser, 1990 Laureate World Food Prize.

John Niederhauser, a senior consultant to the Center in the 1970s and winner of the World Food Prize in 1990, talked about "A Century and a Half of Late Blight Pandemic." He also indicated that the Mexican program PICTIPAPA (International Cooperative Program on Late Blight) and CIP’s proposed global initiative on late blight would work together well.

Niederhauser gave a history of the disease, starting from the Irish famine of 1845. He mentioned the German scientist de Bary, who proved in 1865 that the fungus Phytophthora infestans caused late blight disease. He also discussed the Bordeaux mixture for chemical control, the discovery of oospores, the use of wild species Solanum demissum for resistance, A1 and A2 mating types of the fungus, and the escape of the A2 fungus from Mexico in 1976.

"International collaboration is the only stable strategy for sustaining an initiative," Niederhauser stated. The goal is to find more durable field resistance to the disease because scientists have never found immunity to P. infestans.

Niederhauser stressed the need to study the relationship between late blight and tuber blight, the latter a disastrous effect of the former. He also postulated, "We can take a susceptible commercial potato variety, incorporate some resistance genes, singly or in combination, and emerge with a more effective commercial cultivar."

Niederhauser challenged CIP and the public. "The potato represents an outstanding opportunity to feed the world in the 21st century. Its future is as a crop grown under rainfall, but, if it needs fungicides, many farmers won´t be able to grow it. We have much information and marvelous science, but there is pandemonium now. We need to establish realistic research orchestrated by an international institution. CIP´s work will be essential."

The Global Late Blight Initiative. Dr. Peter Gregory, CIP Deputy Director General, Research

Late blight is posing a renewed threat to the world’s potato crop. The best way to avert this danger is by collaborative research on a global scale to build durable genetic resistance to the disease, thus providing the basis for integrated control in which new resistant varieties replace chemical pesticides in the pivotal role.

This major challenge requires more scientific expertise, facilities, and financial resources than any single research group can provide.

For these reasons there is an urgent need for a highly collaborative, global late blight research initiative that we at CIP believe should be based on the following elements:

A focus on the developing countries of Asia, Africa, and Latin America, with substantial spin-offs for all potato-producing countries.

Collaborative research partnerships involving national research programs, universities, non-governmental organizations, and the private sector.

Complementarity in late blight research between industrialized and developing countries.

A combination of conventional and molecular techniques to enhance and utilize durable resistance.

Funding for the initiative will be requested at a level of $2.5 million per year over 10 years.

Resistance: The Foundation of Integrated Pathogen Management of Late Blight (Phytophthora infestans Mont. de Bary)

George R. Mackay, Director of Genetic Resources, CIP.

There are three principal components to the integrated control of late blight.

1. Elimination and/or reduction of the source(s) of inoculum.

2. Utilization of agronomic practices which minimize spread.

3. Application of chemical fungicides.

Since the outbreaks of the middle of the last century devastated the crop in many countries in Europe, particularly in Ireland, these measures have allowed the continued cultivation of relatively susceptible varieties; although resistant alternatives would greatly augment all other methods of control. Despite phytosanitary hygiene and good agronomic practice, sources of inoculum have never been entirely eliminated even in the sophisticated farming systems of Europe and the USA, where late blight remains an annual problem and fungicides are the only effective control. This situation is exacerbated in Less Developed Countries where already many of the integrated control measures are not in practice possible. The increasing spread of new strains of A1 and A2 mating types around the world and the probability of a soil-borne resting spore stage becoming an additional source of inoculum, will render some current IPM strategies even less effective than they are now. Resistance is the only truly effective control and is complementary to all the rest, including fungicides.

CIP is therefore of the opinion that the development of durably resistant cultivars should be the top priority for the Global Initiative and its research priorities are a reflection of this.

Epidemiology and Ecology of Phytophthora infestans.

Stephen B. Goodwin USDA-Agricultural Research Service, Purdue University, USA

Migrations of Phytophthora infestans (Mont.) de Bary have had a profound impact on the epidemiology of late blight disease and on the ecology of the pathogen. P. infestans most likely evolved in central Mexico. The first migration out of Mexico of one clonal lineage of the A1 mating type occurred in the 1840s, caused the Irish potato famine, and was distributed throughout the world. A second migration out of Mexico occurred in the 1970s. This migration initiated the current resurgence of late blight disease. A third migration was probably from northwestern Mexico into northern North America in the early 1990s. New genotypes, and the A2 mating type in these migrations have had severe consequences for the epidemiology and disease management strategies, of this devastating pathogen.

Epidemiology of late blight in the highland tropics - disease

management and research needs.

Greg Forbes, CIP Quito.

Late blight of potato behaves differently in the highland tropics (HT) than in the temperate zone (TZ). One of the primary differences is that potatoes and other hosts of the pathogen are grown year-round in the HT, thus providing a source of continuous inoculum. For this reason, IPM techniques based primarily on sanitation will probably not work in the HT. In contrast, average temperatures are lower in the HT than in the TZ, which tends to slow the epidemic. IPM components which reduce the rate of the disease should be especially effective in the HT. Examples of rate-reducing components are host plant resistance, fungicides and many cultural activities. An initial assessment of the many different combinations of IPM components may best be done with computer simulation. An example was given which equated effects of temperature due to changes in altitude with appropriate modifications in spray schedules.

Role of the pathogen in analyses of host resistance.

William E. Fry, Cornell University, U.S.A.

Migrations of Phytophthora infestans have worsened late blight problems worldwide and have elevated the importance of resistant cultivars in potato production. Because migrating strains of the pathogen contain many specific virulences, R-gene resistance seems unlikely to provide long term benefit. Because migrating strains are also more aggressive, there needs to be a higher level of "general resistance" in cultivars worldwide. Some simulation analyses indicate that in the absence of increased host resistance, fungicide use might be increased by 50-100%. Analyses of host resistance needs to be accomplished with recent migrating strains under conditions that favor disease development.

Durable resistance to late blight and progress in accomplishing it.

Colon, L.T., Budding, D.J., Vleeshouwers, V.G.A.A. & J. Hoogendoorn,

CPRO-DLO, The Netherlands.

Many sources of resistance to late blight are available, but only field resistance of S. tuberosum, linked to lateness, is known to be durable. Other sources, including S. berthaultii, S. microdontum and S. nigrum, have higher resistance, but of unknown durability. The mechanism in all cases, including that of durable resistance, seems to be a hypersensitive reaction. Gene mapping of the S. microdontum and S. berthaultii resistance and transposon-mediated isolation of the R1 gene may soon reveal the mechanisms involved. So far, only long-term exposure to a wide range of late blight genotypes can reveal the durability of a resistance gene. Genotype by environment interactions and tuber resistance are other important aspects of resistance to this disease.

Tuber blight resistance: Epidemiology and control.

James M. Duncan. Scottish Crop Research Institute, U.K.

Tuber blight occurs mainly when inoculum washes down from infected foliage, often from undetected foliage blight low in the canopy. Spread from infected tubers to nearby tubers can occur in wet soil. High levels of tuber blight can result if tubers are harvested in wet weather. Thorough destruction of haulms prior to harvest is recommended. Control can be achieved through cultural practices, fungicides and host resistance. Biological control could be a useful area for investigation. Resistance to tuber blight exists but although linked to foliage blight, the correlation is not such that selection for foliage blight would ensure high levels of tuber resistance. The timing of tests is critical as the resistance of tubers increases with maturation. Important questions about the epidemiology and nature of resistance are yet to be addressed.

Standard International Field Trials (SIFT).

E. R. French, CIP.

CIP has been assigned the responsibility to coordinate SIFT, a module of PICTIPAPA. Its aim is to organize trials at representative locations in the developing world, with the best late blight resistant clones available from any source. To date, 50 varieties have been released in 21 countries of Africa, Asia and Latin America by testing clones from CIP and Mexico, that incorporate resistance primarily from Mexican germplasm. Tests will be initially conducted at the CIP Quito station (2o S latitude); PICTIPAPA station, Toluca, Mexico (19o N); INTA, Balcarce, Argentina (38o S); CIP's Nairobi, Kenya facility (2o S); and Yunnan University, Kunming,China (25o N).As soon as possible, Bandung, Indonesia (7o S) will be included.

Sources of resistance: Cultivated, wild tuberiferous, and other.

Bodo R. Trognitz. CIP.

Durable resistance to late blight can be identified, in cultivated potatoes, wild tuber-bearing Solanaceae, and plant species distantly-related to the potato feasibility of development of durable resistance depends on detectability and transferability to potato breeding stocks. R gene resistance must be avoided, but it seems to be widespread in wild solanaceous species, even those originating outside the center of diversity of P. infestans.

Research priorities for GILB include the genetics of race non-specific resistance, and the study physiological and biochemical mechanisms that lead to expression of resistance.

Genome analysis for late blight resistance using DNA markers.

Christiane Gebhardt. Max Planck Institut für Züchtungsforschung, Germany

In ten years 500 RFLP loci have been mapped on the twelve potato chromosomes. Approximately 100 of those loci correspond to genes of known function. Dominant resistance alleles acting against Phytophthora infestans have been located A first genetic analysis of quantitative resistance to P. infestans revealed a number of QTL. One QTL was found in the same chromosome segment in which the R1 allele is also located which confers qualitative, race specific resistance to the same fungus. This genetic correlation may indicate that components of quantitative resistance to P. infestans are expressed from multiple alleles at major resistance loci. A target for map based cloning of potato resistance genes is the R1 locus encoding qualitative and eventually quantitative resistance to P. infestans.

Application of polymerase chain reaction (PCR)-based molecular polymorphism assays to potato genetics.

Robbie Waugh, Scottish Crop Research Institute, U.K.

The development of PCR technology led to several assays for detecting polymorphism in DNA. Two of these - AFLP and SSRs - reveal substantially more information per assay than the others (RAPDs, RAMPs and RFLPs) and have been used to generate a large dataset of about 850 markers segregating in a tetraploid population. The markers exhibit all of the expected segregation ratios (1:1, 3:1, 5:1, 11:1 etc.) with about 30% not conforming to expectations. However, no repulsion phase linkages have been detected which is consistent with 4x potatoes behaving as a true autotetraploid. Linkage between markers and components of resistance to Late Blight and Potato Cyst Nematode has been detected.

Resistance Gene Engineering

Marc Ghislain, CIP.

Transgenic potatoes with enhanced resistance to Phytophthora infestans (Pi) can be produced by direct transfer of several genes into varieties with good adaptation and high natural resistance. Several transgenes in a single genotype (oligo-transgenic potatoes) could lead to a synergistic effect on disease resistance. Specific pathogenesis-related proteins (PR proteins), PR5 (osmotin) and PR1 proteins, could alter the development of Pi. Transgenic approaches mimic the hypersensitive reaction activating the natural systemic-acquired resistance. Cloning of genes involved in the gene-for-gene interaction leading to the hypersensitive reaction will allow the engineering of a broad hypersensitive reaction nonspecific to a Pi pathotype. The combination of these systems will presumably give rise to durable extreme resistance to LB.

Statements on Proposed Future Participation in the Global Initiative on Late Blight

INSTITUTO NACIONAL DE TECNOLOGIA AGROPECUARIA (I.N.T.A.)

(ARGENTINA)

Marcelo Huarte

INTA is already participating in an active way in the research related to late blight, and the topics we are interested in are:

 

1. Conventional breeding, both at diploid and tetraploid level.

2. Molecular markers assisted breeding.

3. Phytophthora population studies, monitoring and genetics.

4. Fungicide resistance.

5. Genotype x environment interactions.

6. Agronomic, cultural and chemical control.

7. Somatic fusion and embryo rescue.

8. Genetic transformation and gene cloning

9. Biochemical aspects of the host-pathogen interaction.

All these topics are already being developed to some extent: item 1 through 6 are currently done at Balcarce, item 7 is programmed to start next year at Balcarce, item 8 is currently carried on at Castelar and some aspects of it may start at Balcarce in a few years, and item 9 is jointly carried on between Balcarce and the Facultad de Ciencias Exactas y Naturales de Mar del Plata.

The research team is composed of nine scientists with specialties in plant pathology, breeding, molecular biology, biochemistry, tissue culture and integrated control. A larger number have secondary participation in a team approach.

AGRICULTURE CANADA

(CANADA)

Harold W. Platt

Harold "Bud" Platt of Agriculture Canada at Charlottetown, PEI states they are very interested in the GILB project and regrets not being able to attend the meetings at CIP because of prior commitments. They are prepared to provide staff time and other resources. For example, to conduct studies on foliar and tuber rots caused by the pathogen, with several pathotypes of both A1 and A2 mating types and comparisons to several control entries (internationally produced) for which responses are well known.

Interests extend to both foliar and tuber rot phases (airborne, tuberborne and soilborne) of the disease.

He further states that information on and sources of durable resistance in foliage is vital. However, of equal and in some cases greater priority are the impacts on potato tubers. No-one can afford to have a good yield of low quality, blighted potatoes. If environmental conditions in a larger number of potato production areas (not just Mexico) become conducive to soilborne survival of oospores in sufficient numbers to contribute significantly as sources of disease, late blight resistance for tubers and other subterranean plant parts will be essential for both commercial and non-commercial and specialized potato growers.

Agriculture Canada would also be prepared to collaborate in activities at other research centers and depending on the amounts of monies required, may be able to contribute to a pooled source.

 

CORPORACION COLOMBIANA DE INVESTIGACION AGROPECUARIA (CORPOICA)

(COLOMBIA)

Javier Narvaez

CORPOICA is a non-profit research institute, recently created by the Colombian government, through the Instituto Colombiano Agropecuario (ICA), with the commitment of undertaking basic and applied research and technology transfer activities for the development of the agricultural sector in the country.

In the past, ICA has a potato research program which made important contributions in different areas such as plant improvement, integrated pest management and field testing of advanced genotypes, in close collaboration with CIP. Nowadays, CORPOICA is part of a National Potato Research Network, together with other Institutions like the Universidad Nacional de Colombia and the Federacion de Cultivadores de Papa (FEDEPAPA).

Within this Network, a research project has been proposed to identify resistance genes responsible for either vertical or horizontal resistance to late blight, using genetic and molecular marker technologies, in the cultivated diploid species Solanum phureja as well as in several other wild species of potato. This work is being leaded by Dr. Nelson Estrada, ex-CIP potato breeder, and will count with the participation of several plant pathologists and molecular biologists from the Universidad Nacional, CORPOICA and CIAT’s Biotechnology Research Unit. The Universidad Nacional has also began the collection and characterization of Colombian strains of Phytophthora infestans in the Country, which is considered to be a complementary work for the objectives of the above project. We want this proposal to be considered within the Global Initiative on Late Blight (GILB).

DANISH POTATO BREEDING FOUNDATION

(DENMARK)

Ole Rasmussen and Karl Tolstrup

Danish Potato Breeding Foundation (LKF) have the possibility of contributing to a common project with:

- Gene bank material (consisting of 400 tetraploids, 300-400 wild species

accessions and about 50 dihaploids).

- Wild species crossings, and parental line breeding on tetraploid and

dihaploid level.

- Screening for foliage blight and tuber blight resistance.

- Selection of breeding material for adaptation to temperate climatic

conditions.

The University in Aarhus, Department of Molecular Biology may contribute with:

- Protoplast fusions (electrofusion). Symmetric and asymmetric.

- RFLP, RAPD and PCR techniques for cloning and identification of genes

- GISH-techniques.

At present the University in Aarhus and The Breeding Station in Vandel have a 3-year project concerning protoplast fusion and late blight resistance. The Breeding Station in Vandel routinely tests resistance to late blight and tuber blight as part of their breeding programme for potatoes. The Breeding Station in Vandel employs 12 persons of whom 4 are scientific .

PLANT PATHOLOGY AND BREEDING STATIONS OF I.N.R.A.

(FRANCE)

Didier Andrivon and Daniel Ellisseche

Research on late blight is one of the main topics of our potato programmes. Relevant activities to the initiative are currently carried on both in the Plant Pathology (D. Andrivon, Le Rheu) and Plant Genetics and Breeding (D. Ellisseche, Ploudaniel) Departments. They encompass the characterization, monitoring and genetics of populations of the pathogen, investigations of its epidemiology, the broadening of the genetic base available for resistance breeding and development of durably resistant material for use in potato genotypes adapted to temperate latitudes. Improved material was already obtained from crosses including CIP and INRA progenitors, and part of this material may be available. Both groups are also involved in the Genotype x Environment interaction network launched by Greg Forbes. All these actions are currently carried out with our own financial resources. At the moment, prospects for increase of these resources on the National budget are slim at best.

INRA is eager to continue work in these areas, in the frame and to the benefit of the GILB.

MAX PLANCK INSTITUTE

(GERMANY)

Christiane Gebhardt

To develop genetic resistance to late blight, emphasis is now given to the introduction of race unspecific or quantitative resistance.

The use of RFLP markers and diploid potato lines made possible for the first time the genetic dissection of resistance to late blight in collaboration with the department of Plant Breeding of WAU, The Netherlands.

A RFLP map was constructed covering all 12 Chromosomes. QTL analysis revealed 11 chromosome segments on 9 potato chromosomes showing significant contrasts between marker genotypic classes.

The following is research proposed for improving late blight resistance :

Allele specific and PCR based marker assays will be developed for the best natural sources of field resistance available from germplasm collections at CIP, Mexico and other holders of germplasm. These marker assays can then be used for marker assisted breeding with the resistance alleles present in the genetic material chosen for analysis. This will be done in collaboration with CIP and other participants in the initiative. The first approach will be based on QTL analysis in diploid F1 populations using markers linked to known QTL.

Clones must be diploid wild or cultivated species that can be introgressed into cultivated tetraploid potatoes, and must show reproducibly the desired phenotype of high field resistance to late blight.

A first milestone will be reached when by this analysis it can be demonstrated that certain marker alleles are highly significantly correlated with positive QT alleles is a particular founder population.

A second milestone will be reached when it can be demonstrated that specific alleles of genes of known function are indicative for positive QT alleles.

Another approach will be based on bulked segregant analysis of DNA pools of tetraploid clones using AFLP markers.

QT alleles may be identified which are prominent and specific for a particular genetic background. Mapping of those QT alleles via mapping linked AFLP markers will reveal whether the QT alleles identified correlate with known QTL from previous mapping experiments. Useful AFLP fragments can subsequently be converted in allele specific PCR assays to be used for marker assisted selection of particular QT alleles.

INSTITUTE FOR PLANT BIOCHEMISTRY, UNIVERSITY OF TUBINGEN

(GERMANY)

Lieselotte Schilde

Our group is working in a joint national project on late blight, concentrating on the following topics :

1. Utilization of new resources of resistance from wild species by symmetric and asymmetric protoplast fusion.

2. Identification of hybrids/partial hybrids by FCM, RFLPs, RAPDs and AFLPs.

3. Testing for resistance, so far carried out by Dr. Darsow.

4. Backcrossing of the hybrids/ partial hybrids with breeding lines in cooperation with Institute for Breeding of Crop Plants, Gross Lusewitz, Dr. Tiemann and Dr. Darsow.

5. Identification of resistance transmitting genome parts of the wild species using repetitive and single copy marker ( from Tanksley and C. Gebhardt) , in cooperation with Prof.Vera Hemleben, Institute for General Genetics, Tubingen University.

6. Identification of different components of resistance.

FEDERAL CENTER FOR BREEDING RESEARCH ON CULTIVATED PLANTS AT GROSS LUSEWITZ

(GERMANY)

Ulrich Darsow

Main efforts considering potato/Phytophthora infestans are the following :

1. Continuous assessment of late blight resistance of cultivated and wild species since nearly 30 years.

2. Selection and utilization of sources of resistance on foliage and tubers. A collection of backcross hybrids includes the species dms, sto, plt, pta, ver, scr, tar, hjr, adg, blb, pnt.

3. In addition to conventional breeding methods somatic fusion and embryo rescue play a part. Breeding is partly done on tetraploid and diploid level. We collaborate in a national fusion project with wild species.

4. Selection for foliage resistance is initiated in vitro, followed by selection of young seedlings, several years single leaflet tests, and 2 - 3 years field assessment.

5. Selection for resistance of tubers is done by assessment of little tubers of each seedling or plant from in vitro culture, slice test of field grown tubers for up to 5 years, and 3 years assessment of freshly harvested, uninjured and uninfected field - grown tubers. After this crosses follow.

FEDERAL BIOLOGICAL RESEARCH CENTRE FOR AGRICULTURE AND FORESTRY

INSTITUTE FOR PLANT PROTECTON OF FIELD CROPS AND GRASSLAND, AT BRAUNSCHWEIG

Barbel Schober-Butin

Main duties in my laboratory concerning late blight of potatoes (Phytophthora infestans) are :

1. Determination of pathotypes in the population of P.infestans

Resistance against fungicides

Determination of mating types

2. Determination of isoenzyme-genotypes

3. Investigations into toxin of P.infestans

4. Diagnosis of P.i. in (field) samples by ELISA and PCR

5. Testing of tubers and leaves for resistance against P.i.

6. Epidemiological studies

7. Prognosis of the outbreak of epidemics and directed application of

fungicides

8. Integrated potato production

 

CENTRAL POTATO RESEARCH INSTITUTE

SHIMLA (INDIA)

G.S. Shekhawat

Central Potato Research Institute is actively engaged for the last four decades in breeding/developing cultivars having high degree of resistance to late blight. Wild species S. verrucosum has been exploited for developing cultivars carrying exclusive field resistance. Researches are underway to transfer field resistance/durable resistance from other potential wild spp. to tuberosum background using conventional breeding approaches. To support this activity, we also have a very sound pathological programme wherein variability (be it in the form of mating types, races, fungicide resistance, ploidy or isozyme pattern) in Phytophthora infestans is monitored and put to use in the resistance screening programme.

In view of the above background and the Action Plan prepared by CIP, CPRI can contribute substantially towards GILB. However, additional inputs in the form of (i) finance to establish a modern lab to screen germplasm using molecular markers and develop interspecific hybrids using somatic fusion (ii) Training of Scientists to acquire competence in using high molecular markers and other modern techniques and (iii) Germplasm carrying high degree of durable resistance are required.

 

JAPAN PLANT PROTECTION ASSOCIATION

(JAPAN)

T. Kajiwara

For a collaborative global initiative on late blight, the Hokkaido National Agricultural Experiment Station (HNAES), which is located in the leading production center for potato in Japan, could contribute in the field of plant pathology from Japan.

To establish IPM strategies for late blight, it is likely needed further detailed studies on epidemiology and ecology of the disease in each country. From such point of view, Dr. Masayasu Kato, Laboratory for Plant Diseases of HNAES, will participate in studies on late blight epidemiology including population dynamics.

When the subjects of studies are indicated through the Project Design Meeting, some breeders in HNAES and in Japanese universities may also be able to participate in the project.

JAPAN*

Kazuo Watanabe

Japanese late blight research initiative:

This group consists of govermental research organizations, universities, growers' associations and private sector in Japan, to share the knowledge and experience on late blight epidemics and integrated pest management on the disease in the country. Information will be shared with the GILB network using the internet. A trial of germplasm for the LB resistance is emphasized by using breeding lines available from collaborators elsewhere, especially with North American and European programs. A regional collaboration is also emphasized, particularly with China where prominent collaborations exist with Japanese organizations.

* Dr. Watanabe is a CIP staff member stationed at Cornell. He will soon return to Japan. He was asked to represent Japan at the PDM of GILB.

PROGRAMA INTERNACIONAL COOPERATIVO DEL TIZON TARDIO DE LA PAPA (PICTIPAPA)

(MEXICO)

Héctor Lozoya-Saldaña

POTENTIAL CONTRIBUTION OF PICTIPAPA TO THE GILB

PICTIPAPA arose as a consequence of a half century of experience with late blight in Toluca by the Rochefeller Foundation, INIFAP (the Mexican potato program) and recently in collaboration with the regional PRECODEPA program.

The activities chosen for emphasis are:

1.- Field evaluation in the Toluca Valley, of late blight resistance and its durability in international genetic materials submitted for testing.

2.- Identification of genetic sources of resistance and their maintenance in the Mexican Potato Germplasm Collection. This includes collecting wild species and their observation over time for durability in these and their derived progenies.

3.- Basic studies on the etiology of late blight, epidemiology, biocontrol, genetics of blight populations, race incidence, etc., in Toluca and elsewhere.

4.- Distribution to farmers of new cultivars resistant to late blight and the study of their impact in production.

5.- Establishment of Standard International Field Trials (SIFT) in developing countries around the world.

 

RESEARCH INSTITUTE FOR PLANT PROTECTION

(IPO)/DLO

(THE NETHERLANDS)

Cor van Silfhout

The principal work at IPO is in the field of adaptation of the late blight fungus to durable resistance: 1) Inheritance of components of aggressiveness of the pathogen, 2) Adaptability of the fungus to partial resistance, 3) Effect of aggressiveness on level and impact of resistance in at present available material, 4) Level and type of resistance needed in future to counterbalance the impact of the new fungal population, 5) Impact of level of partial resistance on the production of oospores, 6) Level and/or type if resistance needed to counterbalance both oospore formation in particular and the impact of oospore formation on epidemic development.

The research mentioned above is in cooperation with Dutch Center for Plant Breeding and Reproduction Research (CPRO-DLO) and the Department of Phytopathology of the Agricultural University (AUW) at Wageningen.

CENTRE FOR PLANT BREEDING AND REPRODUCTION RESEARCH (CPRO-DLO)

(THE NETHERLANDS)

J.G. Hoogendoorn

 The Centre for Plant Breeding and Reproduction (CPRO)-DLO can contribute to the GILB with those parts of the ongoing research on potato late blight resistance financed by the Dutch government that are not subject to contractual limitations of confidentially, as follows:

- Integrated pest management.

- Molecular markers for resistance in Solanum microdontum and S.

berthaultii.

- Mechanism of resistance in relation to durability of resistance.

- Transposon tagging and isolation of known R-genes.

These projects are carried out in close collaboration with IPO-DLO, CIP and the Department of Plant Breeding of Wageningen Agricultural University.

Additional subjects for which at present only expertise but no financial support is available are:

- Genotype x environment interaction studies involving many relevant but

different sites in the world.

- Asymmetric protoplast fusion. This technique developed by CPRO-DLO, allows for the transfer of a single chromosome from a non-crossable donor species, such as S. nigrum, to the potato.

CPRO-DLO is willing to assist CIP with applications for additional financing in the Netherlands or concerning international agencies. Dr. L.T. Colon will act as the representative of CPRO-DLO.

 

WAGENINGEN AGRICULTURE UNIVERSITY, DEPARTMENT OF PLANT BREEDING

(THE NETHERLANDS)

Evert Jacobsen

Our mapping research using AFLP markers including R-genes will be discussed.

We developed an integrated map of potato based on RFLPs/biochemical markers/morphological markers/traits and AFLPs. We are currently investigating whether polymorphic AFLP-bands from the same size in different populations are coding for the same sequence or not. This information is essential for mapping all kind of traits, like R-genes, in different populations. At the other hand, our finding will be reported that with respect of resistance to Phytophthora infestans suppressor genes, influencing expression of R-genes, can be involved. In our tagging research 60 transformants with localized Ds-element containing TDNAs have been selected for tagging all kind of traits on different chromosomes. The tagged TDNAs are randomly located on all 12 chromosomes. Research is focused on cloning the R1 and/or R3 genes coding for resistance to late blight.

WAGENINGEN AGRICULTURAL UNIVERSITY, PLANT PATHOLOGY

(THE NETHERLANDS)

Francine Govers

Unraveling the molecular and cellular events during the interaction P. infestans-potato:

(i) Isolated several ipi genes of P. infestans, which are specifically expressed in planta. The encoded proteins may be putative pathogenicity factors.

(ii) Focus on molecules produced by the pathogen which elicit defense responses in plants. We have cloned some genes encoding general elicitors.

(iii) With DNA transformation of P. infestans we test the optimal conditions for inactivating gene function by means of anti-sense genes or co-suppressing transgenes.

(iv) We use the very powerful AFLP DNA fingerprint technology for mapping the P. infestans genome. AFLP's are also used for identification and it might be a powerful tool to study the population genetics.

Epidemiological aspects of potato late blight are studied by M. Zwankhuizen: Overwintering oospores involved in the development of primary foci, which type of primary foci (allotment gardens, volunteer plants or refuge piles) and spread of the disease from the primary foci. DNA fingerprinting is used to reveal the various P. infestans genotypes present and to study the epidemiology.

INSTITUTO NACIONAL DE INVESTIGACION AGRARIA

INIA

(PERU)

Noemí Zúñiga

INIA has research stations with laboratories, greenhouses and fields in many different locations of the coast and highlands where potatoes are grown, and can thus:

Evaluate segregating populations and native varieties for resistance.

Collect isolates for the determination of variation of Phytophthora infestans, including mating types.

Introgress resistance developed for durability, into native varieties.

Assess the effectiveness of different control components of integrated management of late blight in three zones of the highlands that have endemic presence : Chota, Cajamarca; Mayobamba, Huánuco; Comas and Huasahuasi, Junin.

Carry out training and technology transfer of the integrated management of blight for professionals, technicians and farmers.

 

UNIVERSIDAD NACIONAL AGRARIA LA MOLINA

UNALM

(PERU)

Manuel Canto-Sáenz

The University has experimental station in the three major natural regions of Peru : Coastal desert, Andean highlands and Eastern jungle. It has conventional and molecular biology laboratories and specialized scientific and support staff. At present UNALM is involved in the national coordination of selection for resistance to late blight, but could also collaborate in GILB in the following :

Development of a model program for integrated control, emphasizing biological control, cultural practices and resistance; this last using molecular selection techniques.

Utilization of native Andigena as sources of durable resistance.

Identification of the mating types of Phtophthora infestans and studies of the dynamics of populations.

Testing the rational use of fungicides, and search of natural fungicides.

Training in all aspects of late blight disease for graduate students, professionals, technicians and farmers.

Editing of Spanish version of scientific and training publications.

INTERNATIONAL POTATO CENTER - CIP

(PERU)

George Mackay

CIP STATEMENT ON FUTURE PARTICIPATION IN THE GILB

The International Potato Center's access to a vast array of germplasm, and its networks and links designed to deliver and test materials throughout the Developing World, makes it the logical choice to coordinate the

coordinate the Global Initiative on Late Blight (GILB). CIP has a CGIAR (FAO-UNDP-WB) mandate and its policy of more efficiently and effectively transferring technology by collaborating with institutions in both Developed and Developing Worlds is well proven. Those areas in which CIP is working to a greater or lesser extent which can contribute to GILB include:

Germplasm utilization, seeking a broader genetic base of durable resistance to late blight from cultivated, wild, and non-host species for hybridization and introgression as well as developing diploid and tetraploid populations suitable for the identification of molecular markers, genetically mapping, and eventually cloning resistance genes.

The acceleration of combining durable resistance to late blight with resistances to other limiting diseases, such as the common viruses and bacterial wilt, etc., in suitable agronomically adapted material.

Studies on genotype x environment effects on expression of resistance, including the international testing and trialling of cultivars and advanced clones (jointly with PICTIPAPA in S.I.F.T. in future) and research into the epidemiology and population dynamics of Phytophthora infestans.

With the objective of developing and promoting integrated management systems for late blight control, and assessment of its impact in Less Developed Countries of the world.

VEGETABLE AND ORNAMENTAL PLANT RESEARCH INSTITUTE

(SOUTH AFRICA)

Freddie D.N. Denner

Statement as requested what our institution could contribute to the LB project.

1. Evaluation of breeding lines for field resistance against LB. We have already agree to test breeding lines from CIP (organised with Dr P. Ewell).

2. Testing for adaptation of breeding lines with resistance to LB to warm arid climates (eg. Southern Africa).

3. Testing isolates for mating type (A1 or A2).

4. DNA fingerprinting to get evidence about genetic diversity in populations.

5. Testing isolates for metalaxyl resistance.

SCOTTISH CROP RESEARCH INSTITUTE

(UNITED KINGDOM)

James Duncan

SCRI's Role in GILB

SCRI is the lead centre for potato research in the United Kingdom. Through SCRI, GILB would have access to the Commonwealth Potato Collection with 3,000 accessions of wild species and primitive cultivars. SCRI also maintains the R-gene differentials, the field resistance standards and its own germplasm with high levels of blight resistance.

SCRI covers breeding for non-race specific resistance; resistance in wild species; development of sceening for foliage and tuber resistance; mapping of resistance genes including QTLs; environment x resistance interactions, SCRI is a participatant in worldwide GxE experiment; novel blight control strategies; surveying and fingerprinting of late blight isolates; sexual reproduction and molecular biology of the fungus; and modern rapid diagnostics.

In short it would clearly be beneficial to both SCRI and GILB for SCRI to be involved in the project.

SCHOOL OF BIOLOGICAL SCIENCES

(UNITED KINGDOM)

David Shaw

A Global initiative on late blight:

I learn with great interest that CIP is organising a meeting in late March to discuss the co-ordination of research on late-blight disease with a view to developing an action plan. I will be unable to attend but wish to make the following points. Dr Shattock and I and our team in Bangor now have substantial funding to examine the population genetics of P. infestans in U.K. We wish to discover how populations of the fungus are substructured and how far sexual reproduction, which has been possible here for 15+ years, plays a role in generating variation and in overwintering of inoculum. (We are collaborating in this, to some extent, with Jim Duncan (SCRI) who intends to be at the meeting). We believe that many other groups in Europe and in the Americas are involved in characterising the fungus but with notable exceptions (e.g. our collaboration with Former Soviet Union and Egypt) there is no coordination of this activity. I note that little of the proposed meeting will be devoted to proposals to co-ordinate work towards a better understanding of the fungus; this I think ought to be a prominent topic.

I would be most obliged if you could keep me informed of how the project design develops as a result of the meeting. I would be happy to contribute in any way to your formulation of the action plan which you will present at Jakarta in May.

I do hope that the CIP meeting is a success and that collaboration across the globe in both breeding and pathology will become a reality.

CORNELL UNIVERISTY

(UNITED STATES)

William Fry

Cornell University can provide an integrated education for plant breeders and plant pathologists interested in late blight. Additionally we have wide-ranging depth of expertise concerning potato insects, pathology, weeds, seed production, physiology, genetics (traditional, molecular), and culture.

We maintain a worldwide germplasm for P. infestans, and have expertise in genetics (molecular, traditional, population), epidemiology, and integrated management of the pathogen. We can serve as a facilitator for projects among institutions throughout the world. We cannot provide university funding, but can leverage funds from other sources. Faculty expertise is usually available as a university contribution.

UNIVERSITY OF ARIZONA

(UNITED STATES)

Michael Stanghellini

Employment of biosurfactant-producing bacteria, the biosurfactants and/or synthetic surfactants themselves, as a new and potentially efficacious method for the control of destructive foliar, stem and root diseases caused by zoosporic plant pathogens. We have found that surfactants (synthetic as well as those produced by certain fluorescent Pseudomonas spp.), rapidly lyse zoospores.

UNITED STATES DEPARTMENT OF AGRICULTURE AGRICULTURAL RESEARCH SERVICE

(UNITED STATES)

Roy Gingery

USDA-ARS places a high priority on potato late blight research efforts and is conducting an active research program directed at reducing losses caused by this disease. ARS is pleased to participate in the development of the Global Initiative on Late Blight and to assist in its implementation. ARS will finance expenses of its representatives as they participate in GILB and related activities.

PURDUE UNIVERSITY/ USDA-ARS

(UNITED STATES)

Steve Goodwin

The Global Initiative on Late Blight and Purdue University Scientists at Purdue can provide experience, leadership and guidance in identification of Phytophthora-active proteins, and in the production, initial screening and testing of transgenic plants that overexpress genes involved in pathogen resistance. Projects under way at Purdue include: the introduction of a) genes encoding currently available pathogenesis-related proteins, and b) those with activity-enhancing modifications that increase the level of resistance to P. infestans in potato; and isolation and characterization of genes involved in pathogen resistance, including signal transduction components, in tomato. Additional funding for the production of new transgenics and for field testing of transgenic plants is needed to accelerate this research.

P R O G R A M

CIP Twenty-fifth Anniversary Symposium and Project Design Meeting on

the GLOBAL INITIATIVE ON LATE BLIGHT

March 17-20, 1996

Richard Sawyer Auditorium

CIP Headquarters, La Molina

Lima - Peru

Arrivals Friday, March 15-Sunday, March 17, 1996

Inaugural Event : Sunday, March 17

Pachamanca/Earth bake

CIP Gardens, next to Auditorium

16:00 Refreshments and watching the setting up of the bake

17:00 Dining

 

 

CIP Twenty-fifth Anniversary Symposium

Chairperson : Dr. Jose Valle Riestra

Monday, March 18, 1996

09:00 Welcome. Dr. Hubert Zandstra, Director General, CIP.

09:15 Looking Ahead after 25 years of Progress at CIP. Dr. Richard L. Sawyer, Founding Director General of CIP

10:00 A Century and a Half Late Blight Pandemic. Dr. John Niederhauser, 1990 Laureate World Food Prize

10:30 Refreshments

11:00 The Global Initiative on Late Blight (GILB) Dr. Peter Gregory, Deputy Director General for Research, CIP

11:30 Resistance, the Foundation of Integrated Management of Late Blight. George Mackay. Director of Genetic Resources, CIP

12:00 - 13:00 Tour of CIP

PROJECT DESIGN MEETING for the Global Initiative on Late Blight (GILB)

** Monday, March 18th

A forward view on Variation and Epidemiology of Phytophthora infestans

Chairperson : Vilhelm Umaerus, Sweden

Secretary : Rebecca Nelson, IRRI, Philippines

14:30 Epidemiology and ecology of Phytophthora infestans. Steve Goodwin, USDA-Purdue University, USA

15:00 Discussion

15:30 Refreshments

15:45 Epidemiology of late blight in the highland tropics - disease management and research needs. Greg Forbes, CIP Quito.

16.15 Discussion

17:30 Refreshments in the garden

** Tuesday, March 19

Looking ahead at Host Resistance Sources and Testing

Chairperson : Marcelo Huarte, INTA Argentina

Secretary : Juan Landeo, CIP

08:30 The role of P. infestans in analysis of host resistance. Bill Fry, Cornell University, USA.

09:00 Durable resistance and progress in accomplishing it. Leontine Colon, CPRO/DLO, Netherlands.

09:30 Discussion

10:00 Refreshments

10:30 Tuber blight resistance, epidemiology and control. Jim Duncan, Scottish Crop Res. Inst. - UK.

11:00 Standard International Field Trials (SIFT). Ed French, CIP.

11:30 Resistance sources: Cultivated (4x and 2x); wild tuberiferous species; other Solanum. Bodo Trognitz, CIP.

12:00 Discussion

13:00 Lunch

Molecular Perspectives to Enhance Resistance

Chairperson : Evert Jacobsen, Wageningen Agricultural Univ.,

Netherlands

                    Secretary : Hans Sandbrink, CPRO/DLO Netherlands

14:30 Genetic mapping and cloning of resistance genes. Christiane Gebhardt, Max Planck Institute, Germany.

15:00 Molecular tools. Robbie Waugh, SCRI-UK.

15:30 Refreshments

16:00 Resistance gene engineering. Marc Ghislain, CIP

16:30 Discussion

17:30 Refreshments in the garden

18:30 Dinner for CIP residents; departure for others

** Wednesday, March 20th

Gilb Strategies

Chairperson : Peter Gregory, CIP

Secretary : Greg Forbes, CIP Quito

08:30 Establishment of division of responsibilities in conducting fundamental and applied research worldwide, and development of a proposal for the GILB.

10:30 Refreshments

11:00 Continue to develop the GILB proposal

13:00 Lunch

14:30 Continue to develop the GILB proposal

15:30 Refreshments

15:45 Continue to develop the GILB proposal

 

LIST OF PARTICIPANTS

Project Design Meeting of the Global Initiative on Late Blight

March 17-20, 1996

CIP Headquarters, La Molina

Lima - Peru

 

Dr. Marcelo A. Huarte

Coordinador Subprograma Papa

INTA

Casilla de Correos 276

7620 Balcarce

Buenos Aires, ARGENTINA

Phone: 54-266-22040

Fax: 54-266-21756

Email : huarte(at)esagro.gov.ar

 

Dr. Enrique Fernandez-Northcote

PROINPA

Casilla Postal 4285

Cochabamba

BOLIVIA

E-mail : proinpa(at)papa.bo

 

Dr. Richard Tarn

Fredericton Research Centre, AAC

P.O. Box 20280

Fredericton, New Brunswick

CANADA, E3B 4Z7

Phone: 506-452-3260

Fax : 506-452-3316

E-mail: trnr(at)em.agr.ca

 

Dr. Javier Narvaez Vasquez

 

		Priority
I	Use of existing breeding materials to improve horizontal resistance to late blight in both foliage and tuber	I
	a. SIFT: As a mechanism to measure impact of elite resistant materials and transfer of technology it may forward complementary information to GxE.
	b. Strengthen the development of breeding population with horizontal resistance and the exchange of breeding lines among breeding programs.
	c. Identify, characterize and utilize new sources of horizontal resistance
II	Upgrading and extension of present GxE studies on late blight in the foliage.*(See Mackay handout)	II
III	Refinement and standardization of testing for both foliage and tuber resistance	I
IV	a) Development of molecular tools for application in practical breeding.	I
	b) Genetic studies using molecular techniques and development of characterized segregating diploid and tetraploid populations (Map-based cloning and/or transposon tagging of R Genes, identification of QTL)	II
V	Studies on fungal population dynamics	II
VI	Update current IPM studies and related transfer of technology	I
VII	Enhance R & D on limited gene/chromosome transfer tecnology	III
VIII	Transgenic approach using potato and non-potato sources as constructs	III

 

 

The consistent low ranking, and consistency of view (lowest c.v.’s), for limited chromosome/gene transfer and the use of non-potato transgenes was supported by verbal and written comments. Most participants agreed that this area of work is receiving adequate attention, particularly from the private sector. However, most participants stated that researchers in this area of work should be encouraged to join under GILB, although additional funding should not be sought.

During discussions, the additionality of the GILB priorities to ongoing research and development was continuously stressed. It was recognized that conventional, or classical breeding and selection, are central to any attempt to enhance durable resistance in new potato varieties. The GILB priorities are perceived as areas of research that will augment the efforts of classical breeders to more efficiently and effectively achieve their aims. They are not alternatives. It is assumed that efforts at CIP and elsewhere to breed resistant varieties through conventional means will continue to be supported. Otherwise, additional support for conventional breeding should be included in GILB priorities.

In addition to the discussion on research priorities, the meeting divided into four groups to discuss:

1. Variation and epidemiology of Phytophthora infestans. Chair: Dr. V. Umaerus.

2. Interactions of host and pathogen. Chair: Prof. E. Jacobsen.

3. Host resistance, including conventional breeding and molecular approaches. Chair: Dr. M. Huarte.

4. The management of the GILB. Chair: Dr. L. Hardin.

On resumption of the full meeting, each chairperson delivered a summary of his group’s opinions and views. Each presentation followed a slightly different style but all recommendations were in accord with the consensus outlined above.

1. Variation and epidemiology of P. infestans: Dr. Umaerus’ group decided that there is insufficient information available to extrapolate from the situation in the Toluca Valley to what may become the situation in the potato-producing regions of the developing world. The group was of the opinion that there is a need to gain a greater understanding of the present scenario regarding the population biology of the fungus. Whereas oospore biology may be construed as a subset of this, it is sufficiently important to be treated as a separate subject for research and development. Integrated pathogen management was perceived as extremely important. The specific areas of interest which could feature in GILB in terms of research into the biology and epidemiology of the fungus are:

Population biology--the support for surveillance research and linkage for internationally-supported surveillance in developing countries.

Oospore biology--networking and other funded projects in developed countries, plus support for research in India and Mexico (Toluca).

IPM--GILB should provide mechanisms for deployment and management of resistant cultivars, ensure coordination and linkage between LDCs and developed countries, and validate or adapt IPM strategies to the tropics.

2. Interaction of host and pathogen: Professor Jacobsen’s group succinctly summarized its findings into those areas of research and development that should be part of the network so as to enhance collaboration information exchange, and stimulate funding.

Research and development on avirulence genes, infection induced resistance, elicited genes and host range (on the fungus-side) should all feature as part of GILB networking activities, but require no further stimulation. On the plant-side, the group perceived a need for standardization of resistant tests, etc. However, they perceived a need for more stimulation of research and development into germplasm enhancement; in particular the identification of "durable resistant alleles", to be tested by CIP and developing countries in partnership with laboratories in developed countries. There is a need to test for new sources of resistance, and this should include research and development on histological aspects and mechanisms of resistance. The mapping of resistance genes including QTL is an ideal area for fruitful collaboration between developed country laboratories, CIP, and their LDC’s partners. There is a specific need to stimulate research into the relationship between resistance and maturity (early vs. late) and this could include environmental interactions, e.g. photo-period, on expression of resistance. The group also confirmed that the cloning of genes and genetic engineering of resistance requires no additional stimulus under auspices of the GILB, but that institutions working in this area should be encouraged to join the network.

3. Breeding and selection for host resistance: Dr. Huarte’s group summarized its conclusions in terms of those areas of maximum priority (I) for the GILB, others of secondary importance (II), and those few areas of work that do not require GILB support, but should become part of the networking process (III) (Table 2). The group was of the opinion that maximum priority should be given to the use of existing breeding material to improve levels of horizontal resistance in both foliage and tubers. They believe that the planned Standard International Field Trials (SIFT) will provide a mechanism to both assess the potential impact of elite resistant germplasm from around the world, expedite its availability to LDC’s, and assist in technology transfer to national systems. They saw GILB as a means to strengthen the development of more durably resistant populations by encouraging the exchange of breeding lines among breeding programs, as well as identifying, characterizing, and utilizing new sources of resistance. They attached highest priority (I) to upgrading and extending the present informal study on genotype x environment (GxE) interactions on the expression of late blight resistance, as outlined in a recent concept note sent to IFAD. According to the group’s report, there is a need to refine and standardize testing for resistance. High priority should be given to the development of molecular tools for application in practical breeding programs. Current IPM strategies should be updated and related technology transferred to LDC’s. Studies on fungal populations and genetic studies/map-based cloning and transposon tagging of resistance (R) genes was given a lower priority for GILB support (II). Research into limited chromosome/gene transfer techniques and the use of transgenics were of lowest priority for GILB (III).

4. Management of the GILB: Dr. Hardin’s group provided a view of how the GILB might be managed, a process that later met with approval of the participants. The GILB is to stimulate, integrate and coordinate R&D on late blight. It should assist in developing common efforts which will require funding. It will establish and facilitate the global late blight network. CIP, it said, is the logical convenor of the GILB.

It was agreed that there needs to be a management entity, including a coordinating secretariat with an executive secretary and appropriate support staff.

The GILB will require a steering committee of perhaps 6 carefully selected individuals of international stature, representative of developed countries, LDCs and scientific disciplines. They will need to agree and establish meeting criteria, frequency, etc.

The GILB program components will comprise projects and activities that are

a. Priority efforts to be partially or fully funded via GILB through CIP. These could take the form of grants in aid; contracts and joint efforts with support in kind.

b. Significant contributions to the global late blight network which carry their own support.

The functions and activities of the management entity should include:

1. Constitute the global late blight network

2. Organize support (funds and collaboration)

3. Allocate resources

4. Provide accountability, reporting

5. Facilitate scientific exchange, communications (meetings, publications, e-mail, etc.)

6. Assure science quality

7. Provide open access, ensure transparency

8. Provide oversight to coordinating secretary

9. Evolve own role, responsibilities, structure

 

	Average	Rank	C.V. %
Phase I: Years 1-3
- Refinement of molecular techniques, map-based cloning and/or transposon tagging of R genes, identification of QTL for quantitative resistance	4.8	5	45
-Development of characterized segregating populations (2x & 4x)	4.1	2	62
-Refinement and standardization of testing for resistance	4.4	3	58
-Upgrading and extension of present GxE study on resistance	4.7	4	46
-Studies on fungal populations dynamics	4.9	6	52
-Update current IPM strategies	5.4	7	41
-Identify sources of resistance, existing adapted cvs. (SIFT); wild species and primitive forms	4.0	1	65
-Enhance R&D on limited gene/chromosome transfer techniques	7.8	8	21
-Transgenic approach using non-potato sources as constructs	8.0	9	26
Phase II: Years 4-6
-Clone R genes, determine mechanisms, transform into susceptible cvs.	3.6	4	37
-Utilize QTL to increase selection efficiency and negate GxE effects	3.0	2	54
-Extend field trials (SIFT/GxE) to include products of Phase I (select in situ, LB + adaptability)	2.3	1	57
-Utilize limited chromosome transfer techniques & Ag. tumefaciens to introduce resistance(s) into adapted cvs.	4.9	6	22
-Continue sampling and monitoring of the pathogen complex--epidemiology/aggressivity, etc.	3.3	3	42
-Controlled field trials of transgenics with novel resistance	4.4	5	40
Phase III: Years 7-10
-Transfer improved germplasm to NARS, NGOs, etc.	1.9	1	59
-Training: IPM and application of modern techniques	2.6	2	33
-Impact assessment	3.3	3	31
-Risk assessment and durability testing of non-host options	3.9	5	22
-Monitoring: prediction of future needs, future R&D prioritization	3.8	4	35

                                                     

Foreword

Potato late blight, caused by the fungus Phytophthora infestans, is the single-most costly biotic constraint to global food production. It is also the cause of one of the largest uses of agrochemicals.

 Over the past two decades, hardier, more aggressive forms of the fungus have spread to virtually all major potato-producing countries in the northern hemisphere and are now well established in the developing world . Most scientists agree that the new forms of the fungus could lead to catastrophic crop losses and even larger applications of chemical fungicides in the future.

 Urgent action is needed to address this problem. Research collaboration must be catalyzed on a global scale to develop integrated pathogen management programs in which new potato cultivars with durable genetic resistance to late blight, play the pivotal role. To set this process in motion, a project design meeting was held at the International Potato Center (CIP) in Lima, Peru, March 18-20, 1996. Presentations and discussions involved 41 participants, from developing and industrialized countries, as well as 15 CIP scientists and administrators.

 The results of the meeting, as presented here, form the basis for a research proposal which we believe will benefit the developing countries of Asia, Africa, and Latin America. It should also produce substantial spin-offs for other potato-producing countries. When fully implemented, beginning in calendar year 1997, the project will be known by the acronym GILB, i.e. the Global Initiative on Late Blight.

 

Edward R. French

Leader, Disease Management Program   George R. Mackay

Director of Genetic Resources

 

Conclusions of the Project Design Meeting on the Global Initiative on Late Blight

 

Introduction

The meeting stimulated constructive discussion on how best to integrate and coordinate late blight research between scientists representing institutions from both developed and developing countries.

There was general recognition of the need to maintain as well as increase funding to enhance late blight control. Several proposals have already been made and others are in preparation. Each involves one or more of the research and development priorities agreed upon at the meeting (Table 1).

It was agreed that a global late blight network should be established. The comments, discussions, and suggestions received from participating scientists provide a strong basis for a prospectus to be submitted by CIP to donors during the CGIAR meeting in Jakarta, Indonesia, May 1996.

Suggestions for the management of the GILB network were discussed and agreed upon by consensus.

 Twenty six participants provided suggested rankings for future research and development priorities as outlined in a paper submitted to the CGIAR Technical Advisory Committee in March 1996. The rank data are summarized in Table 1. This report is an attempt to distill this information into a coherent summary

Research and Development Priorities for the GILB

Most of the discussion concerned CIP’s 9 priority areas, as listed under GILB Phase 1 (years 1-3). As seen in Table 1, research priorities 1 to 7, inclusive, were deemed to be of equal priority. Considering the fairly high coefficients of variation, these priorities were not significantly different. However, it is noteworthy that the identification of sources of resistance from existing adapted cultivars, using the Standard International Field Trial (SIFT) and the identification of new sources of resistance from primitive forms and wild species, ranked first overall. This concurs with many comments from participants who perceive this as a principal function of CIP with its unique access to the diverse germplasm.

The low ranking (7) for integrated pathogen management (IPM) may underestimate the importance of this area of work. Many comments were received suggesting that "training" must be an important component of the GILB, and that CIP should ensure that this component receive attention "to ensure relevance and utilization of IPM in LDCs".