Advances in BOTANICAL RESEARCH incorporating Advances in Plant Pathology VOLUME 40 Advances in BOTANICAL RESEARCH incorporating Advances in Plant Pathology Editor-in-Chief J. A. CALLOW School of Biosciences, The University of Birmingham, UK Editorial Board A. R. HARDHAM J. S. HESLOP-HARRISON M. KREIS R. A. LEIGH E. LORD D. G. MANN P. R. SHEWRY D. SOLTIS Australian National University, Canberra, Australia University of Leicester, UK Universite de Paris-Sud, Orsay, France University of Cambridge, Cambridge, UK University of California, Riverside, USA Royal Botanic Garden, Edinburgh, UK IACR-Long Ashton Research Station, UK University of Florida at Gainesville, USA Advances in BOTANICAL RESEARCH incorporating Advances in Plant Pathology Series Editor J.A. CALLOW School of Biosciences, University of Birmingham, Birmingham, UK VOLUME 40 2003 Amsterdam Boston Heidelberg London New York Oxford Paris San Diego San Francisco Singapore Sydney Tokyo ELSEVIER Ltd The Boulevard, Langford Lane Kidlington, Oxford OX5 1GB, UK 2003 Elsevier Ltd. All rights reserved. This work is protected under copyright by Elsevier, and the following terms and conditions apply to its use: Photocopying Single photocopies of single chapters may be made for personal use as allowed by national copyright laws. Permission of the Publisher and payment of a fee is required for all other photocopying, including multiple or systematic copying, copying for advertising or promotional purposes, resale, and all forms of document delivery. Special rates are available for educational institutions that wish to make photocopies for non-profit educational classroom use. Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone: (+44) 1865 843830, fax: (+44) 1865 853333, e-mail: [email protected] You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting ‘Customer Support’ and then ‘Obtaining Permissions’. In the USA, users may clear permissions and make payments through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA; phone: (+1) (978) 7508400, fax: (+1) (978) 7504744, and in the UK through the Copyright Licensing Agency Rapid Clearance Service (CLARCS), 90 Tottenham Court Road, London W1P 0LP, UK; phone: (+44) 207 631 5555; fax: (+44) 207 631 5500. Other countries may have a local reprographic rights agency for payments. Derivative Works Tables of contents may be reproduced for internal circulation, but permission of Elsevier is required for external resale or distribution of such material. Permission of the Publisher is required for all other derivative works, including compilations and translations. Electronic Storage or Usage Permission of the Publisher is required to store or use electronically any material contained in this work, including any c