The Role of Plant Pathology in Food Safety and Food Security

Transcription

1 The Role of Plant Pathology in Food Safety and Food Security

2 Plant Pathology in the 21st Century For other titles published in this series, go to

3 R.N. Strange Editors Maria Lodovica Gullino The Role of Plant Pathology in Food Safety and Food Security

4 Editors R.N. Strange School of Biological and Chemical Sciences Birkberk College University of London UK Maria Lodovica Gullino Universitá degli Studi di Torino, Italy Low yield of a banana plant derived from a sucker (lower picture) and higher yield of banana plant grown from tissue culture (upper picture): see article by James Onsando and Florence Wambugu (page 80). ISBN e-isbn DOI / Springer Dordrecht Heidelberg London New York Library of Congress Control Number: Springer Science+Business Media B.V No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Cover illustration: Photograph courtesy of Dr. James Onsando Printed on acid-free paper Springer is part of Springer Science+Business Media (

5 Foreword This collection of papers represents some of those given at the International Congress for Plant Pathology held in Turin in 2008 in the session with the title The Role of Plant Pathology in Food Safety and Food Security. Although food safety in terms of Is this food safe to eat? did not receive much direct attention it is, never theless, an important topic. A crop may not be safe to eat because of its inherent qualities. Cassava, for example, is cyanogenic, and must be carefully prepared if toxicosis is to be avoided. Other crops may be safe to eat providing they are not infected or infested by microorganisms. Mycotoxins are notorious examples of compounds which may contaminate a crop either pre- or post-harvest owing to the growth of fungi. Two papers in this book deal with toxins, one by Barbara Howlett and co-workers and the other by Robert Proctor and co-workers. In the first of these, the role of sirodesmin PL, a compound produced by Leptosphaeria maculans, causal agent of blackleg disease of oilseed rape (Brassica napus), is discussed. The authors conclude that the toxin plays a role in virulence of the fungus and may also be beneficial in protecting the pathogen from other competing micro-organisms but there seem to be no reports of its mammalian toxicity. In the second paper, attention is drawn to the many plant diseases caused by the fungus, Fusarium proliferatum, and the fact that it produces a wide range of biologically active metabolites, including the fumonisins. These compounds, in a related fungus, Gibberella fujikuroi, play a role in virulence but have also been identified as carcinogens. The remaining chapters of the book deal with the security of our crops and how this may be improved. In the first paper, Ziegler and Savary document the importance of rice, particularly for the poor, and point out that the recent price spike has been catastrophic for them as, even before the increase, many were spending at least half their budget on food. Regarding the toll taken by disease, this is difficult to estimate but under current agronomic conditions grain yield reductions are thought to be about 15%. The paper by Emmanuel Moses was concerned with the improved yields of cassava in cultivars that are resistant to African Cassava Mosaic Disease and, with the help of a grant from the International Society for Plant Pathology, the education of farmers in the recognition of diseases and their avoidance by using healthy material for vegetative propagation. Yield increases have been spectacular, double those of the yields previously obtained in some instances. v

6 vi Foreword Several chapters deal with quarantine measures. Increases in trade in plants and their products carry increased risks of importing dangerous pathogens. The paper by van der Graaff and Khoury goes further in that it encompasses the policy and regulatory frameworks (including instruments and activities) for analyzing and managing relevant risks to human, animal and plant life and health, and associated risks to the environment as well as food safety, zoonoses, the introduction of animal and plant diseases and pests, the introduction and release of living modified organisms (LMOs) and their products (e.g. genetically modified organisms or GMOs), and the introduction and management of invasive alien species. Scott and Strange recount the involvement of the International Society for Plant Pathology s concern for food security from the 1998 Congress to the present. Following an address by the Nobel Laureate, Norman Borlaug, at that Congress, a Taskforce for Food Security was formed and a meeting took place in Bangkok the following year. Other significant developments include the funding of Emmanuel Moses s project (mentioned above) and the launch of the new journal, Food Security: the Science, Sociology and Economics of Food Production and Access to Food, in association with the publisher, Springer. With the increase in global travel it is inevitable that there has been movement of plant pathogens across evolutionary and geophysical boundaries as described by Evans and Waller. Their paper includes some measures that could be taken to improve phytosanitary control. However, it is conceivable that malicious individuals, disaffected groups of people or the political elite of a country might contemplate using plant pathogens in agro-terrorism, as pointed out by Stack and co-workers. Reassuringly, they conclude that it is difficult to establish a pathogen in a crop at a distance where it will multiply to give a serious plant epidemic. Preventing the introduction and spread of plants and plant products as well as controlling them is the purpose of the International Plant Protection Convention (IPPC) as described by Roberts. Encouragingly, there are now 170 contracting parties to the IPPC. Similar objectives are also espoused by the European and Mediterranean Plant Protection Organization (EPPO) as described by Petter and co-workers. In addition EPPO has been developing Pest Risk Analysis (PRA) for specific plant pathogens. Onsando and Wambugu point out the benefits that have resulted from exploiting biotechnology for plant disease control with several examples ranging from the establishment of healthy tissue culture (see cover of this book) to genetic modification. The latter still excites considerable opposition in Europe where those opposed would, it seems, prefer conventional plant breeding in which many flanking genes besides the one of interest are transferred. As Jonathan Gressel points out in his book, Genetic Glass Ceilings (published 2008), breeding is like getting a spouse with a whole village whereas genetic engineering is like getting a spouse without in-laws! Finally, Hohn, and Schachermayr consider genetic modification (GM) as a new tool in the resistance toolbox and present some exciting results in which plants have been transformed with genes conferring resistance to aphids and, through gene silencing, resistance to viruses. Richard Strange

7 Contents The Role of Plant Pathology in Food Safety and Food Security Plant Diseases and the World s Dependence on Rice... 3 R.S. Zeigler and S. Savary Development of Appropriate Strategies to Control Cassava Diseases in Ghana E. Moses Biosecurity in the Movement of Commodities as a Component of Global Food Security N.A. van der Graaff and W. Khoury Global Food Security ISPP and the Challenge of Food Security Peter Scott and Richard Strange Globalisation and the Threat to Biosecurity Harry C. Evans and James M. Waller Genetic Modification (GM) as a New Tool in the Resistance Toolbox Thomas Hohn and Gabriele Schachermayr The Role of Plant Pathology and Biotechnology in Food Security in Africa James M. Onsando and Florence Wambugu vii

8 viii Contents Mycotoxins The Secondary Metabolite Toxin, Sirodesmin PL, and Its Role in Virulence of the Blackleg Fungus Barbara J. Howlett, Ellen M. Fox, Anton J. Cozijnsen, Angela P. Van de Wouw and Candace E. Elliott Biological and Chemical Complexity of Fusarium proliferatum Robert H. Proctor, Anne E. Desjardins and Antonio Moretti Biosecurity and Quarantine Bioterrorism: A Threat to Plant Biosecurity? J.P. Stack, F. Suffert and M.L. Gullino The Revised International Plant Protection Convention a New Context for Plant Quarantine William Roberts Pest Risk Analysis as Applied to Plant Pathogens Françoise Petter, Sarah Brunel and Muriel Suffert Index