Diagnosing Maize Diseases in Latin America Carlos Casela, Bobby (R.B.) Renfro, Anatole F. Krattiger Editors Published in collaboration with PIONEER HI-BRED INTERNATIONAL, INC. No. 9-1998 Diagnosing Maize Diseases in Latin America Carlos Casela, Bobby (R.B.) Renfro, Anatole F. Krattiger Editors Published in collaboration with PIONEER HI-BRED INTERNATIONAL, INC. No. 9-1998 Published by: The International Service for the Acquisition of Agri-biotech Applications (ISAAA). Copyright: (1998) International Service for the Acquisition of Agri-biotech Applications (ISAAA). Reproduction of this publication for educational or other non-commercial purposes is authorized without prior permission from the copyright holder, provided the source is properly acknowledged. Reproduction for resale or other commercial purposes is prohibited without the prior written permission from the copyright holder. Citation: Diagnosing Maize Diseases in Latin America. C.Casela, R.Renfro and A.F. Krattiger (eds). 1998. ISAAA Briefs No. 9. ISAAA: Ithaca, NY and EMBRAPA, Brasilia. pp. 57. Cover pictures: Pictures taken during the field visits and the diagnostics training workshop in Brazil by ISAAA (K.V. Raman). Available from: The ISAAA Centers listed below. For a list of other ISAAA publications, contact the nearest Center: ISAAA AmeriCenter ISAAA AfriCenter ISAAA EuroCenter ISAAA SEAsiaCenter 260 Emerson Hall c/o CIP John Innes Centre c/o IRRI Cornell University PO 25171 Colney Lane PO Box 933 Ithaca, NY 14853 Nairobi Norwich NR4 7UH 1099 Manila USA Kenya United Kingdom The Philippines [email protected] Also on: www.isaaa.cornell.edu Cost: Cost US$ 10 per copy. Available free of charge for developing countries. Contents Introduction and Overview: Diagnosing Maize Diseases with Proprietary Biotechnology Applications Transferred from Pioneer Hi-Bred International to Brazil and Latin America................................................................1 Anatole Krattiger, Ellen S. Kulisek and Carlos Casela The Current Status of Maize Diseases in Brazil ...............................................................................................5 Fernando T. Fernandes Maize Rusts .....................................................................................................................................................8 R. Renfro The Phaeosphaeria Leaf Spot.........................................................................................................................15 Carlos Roberto Casela Dalbulus maidis Identification, Biology, Ecology and Pest Status..................................................................18 Lowell R. Nault Maize Viruses and Mollicutes: Interactions Between the Host and Pathogens..............................................22 E. W. Kitajima Characteristics of the High Plains Virus (HPV) and Breeding for Resistance in Maize ..................................27 Alberto Marçon, Shawn M. Kaeppler, Stanley G. Jensen and Jeffrey S. Hall Corn Leafhoppers as Vectors of Maize Pathogens in Brazil...........................................................................34 José Magid Waquil The Potential Collaborative Role of CIAT in Promoting Maize Virology Research in Latin America.............43 Francisco J. Morales and Shivaji Pande Disease Management in Maize ......................................................................................................................46 Richard A. Frederiksen Appendices A. Working Group Recommendations ..............................................................................................53 B. Protocol for Diagnosing Maize Viruses, Corn Stunt and Rayado Fino ...........................................56 i Introduction and Overview Diagnosing Maize Diseases with Proprietary Biotechnology Applications Transferred from Pioneer Hi-Bred International to Brazil and Latin America Anatole Krattiger Ellen S. Kulisek Carlos Casela 1 Executive Director, ISAAA Research Manager/Analytical Biochemistry CNPMS/EMBRAPA 260 Emerson Hall Pioneer Hi-Bred International Rodovia MG 424-KM65 c/o Cornell University 7300 NW 62nd Avenue Caixa Postal 151 Ithaca, NY 14853, USA Johnston, IA 50131, USA 35701-970 Sete Lagos, Brazil In the early 1990’s, scientists in Brazil is valued at about US$700 million. became concerned about the Although total production meets growing spread of unidentified maize today’s Brazilian demand, the average diseases in the crop’s major maize yield at 1.8 tons per hectare is production areas. Researchers at the very low. This reflects the lack of Brazilian National Maize and high-yielding varieties, use of better Sorghum Research Center (CNPMS) soils for other crops and lack of tech- at Sete Lagoas had previously seen nology. virus-like symptoms in several maize varieties, but were unable to identify At the same time, there were reports of them. They had little information on new viruses spreading into Brazil from the development of the diseases and neighboring countries and from other were in need of reliable methods of areas of Latin America. Scientists from detection. At risk was the country’s the International Maize and Wheat Im- nearly 15 million hectare crop. Its provement Center (CIMMYT) in annual production of 30 million tons Mexico had concluded that Brazil’s 1 Krattiger, A.F. Kulisek, E.S. and Casela, C. 1998. Introduction and Overview: Diagnosing Maize Diseases with Proprie- tary Biotechnology Applications Transferred from Pioneer Hi-Bred International to Brazil and Latin America. In Diagnosing Maize Diseases in Latin America (Eds. C. Casela, R. Renfro and A.F. Krattiger). ISAAA Briefs No. 9. ISAAA: NY. Pp. 1-4. 1 problem was a higher prevalence of the corn stunt virus Early in 1993, Brazilian officials contacted the Interna- complex, probably the result of an increase in year tional Service for the Acquisition of Agri-biotech Appli- round cropping of maize. Because of the growing im- cations (ISAAA) for assistance. Following an intensive portance of the crop in Brazil and rapid spread of the survey by ISAAA and discussions with several potential diseases, a national virus detection program was given a donors of the technology, Pioneer Hi-Bred International high priority designation by the country’s Agricultural of Johnston, Iowa (a corporate sponsor of ISAAA since Ministry. CNPMS officials had earmarked funding for 1992), was selected as the partner. staff training and project expenses. The project, brokered by ISAAA to assist Brazil, involved The immediate need was a simple test to quickly iden- the development and donation by Pioneer of its pro- tify the diseases under field conditions. Once that was prietary ELISA technology for detection of diseases in done, scientists could better understand the spread of addition to training CNPMS scientists and technicians in the diseases, undertake control programs and breed laboratory and field techniques. Pioneer also agreed to maize varieties with resistance to the diseases. Although organize and co-sponsor a three-week training program some diseases can be visually diagnosed, many require in Iowa, for a Brazilian scientist, on the development laboratory testing that can take days and weeks to com- and application of ELISA diagnostic kits. plete. As a result of advances in biotechnology, new products and techniques are now available that can re- Of the three major diseases infecting Brazilian maize va- place time-consuming and sometimes inaccurate labo- rieties, two diseases, Corn Stunt Spiroplasma (CSS; a ratory procedures. bacterial disease) and Rayado Fino (RF; a virus), were selected by Brazil and Pioneer for initial study because of their prevalence in Brazil and many other countries in Latin America. The production of enzyme-linked immunosorbent assays (ELISA) is a diagnostic kit in detecting viral and bacterial diseases. These diagnostics are based on a method that uses antibodies to detect disease causing organisms of plants. In the summer and fall of 1993, Ellen Kulisek of Pioneer, developed and perfected two assays to detect CSS and RF viruses and field tested them in Johnston. The anti- Above:Alejandro Ferreira inspecting maize diseases. gens necessary to initiate antibody production were do- Below: Alejandro Ferreira and Dr. Carlos Casela (right). nated by the US Department of Agriculture. The following January, Kulisek trained 14 Brazilian scientists and technicians at the Sete Lagoas research headquar- ters on both laboratory and field use of the assay proce- dures for each of the two ELISAs. The assays worked well because they were sensitive enough to detect in- fected plants that were considered free of disease based on visual observation. Later that year, Carlos Casela of CNPMS benefited from a three-week ISAAA Biotechnology Fellowship at Pio- neer on ELISA development. Meanwhile, CNPMS 2 named a researcher from the in-country training course, Elizabeth de Oliveira, to head a new diagnostic program at Sete Lagoas. There is a strong potential for diagnostics in Brazil that needs to be en- couraged and supported. This requires not only financial support and commitment, but interested members of the sci- entific community who are committed and willing to do- nate their time to this. Pioneer had agreed to precisely this. It Workshop participants during laboratory work at the is also noteworthy that the cost of the project—which CNPMS/ISAAA Maize Disease Manangement workshop was low compared with the value of the diagnostics—was sponsored by CNPMS and Pioneer. Equipped with trained manpower, CNPMS