Microbial Plant Pathogens-Detection and Disease Diagnosis: Bacterial
The bacterial and wall-less phytoplasamal pathogens are comparatively much smaller than fungal pathogens. The morphological characteristics of bacterial pathogens have limited application for their detection and identification. Hence, cultural, biochemica
- PDF / 4,178,582 Bytes
- 276 Pages / 439.37 x 666.142 pts Page_size
- 39 Downloads / 171 Views
wwww
Microbial Plant Pathogens-Detection and Disease Diagnosis Bacterial and Phytoplasmal Pathogens, Volume 2
P. Narayanasamy Former Professor and Head, Department of Plant Pathology Tamil Nadu Agricultural University, Coimbatore, India
P. Narayanasamy Grand Parade Apartments 32 D Thilagar Street, R. S. Puram Coimbatore 641002 India [email protected]
ISBN 978-90-481-9768-2 e-ISBN 978-90-481-9769-9 DOI 10.1007/978-90-481-9769-9 Springer Dordrecht Heidelberg London New York Library of Congress Control Number: 2010938430 © Springer Science+Business Media B.V. 2011 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: Sesamum phyllody (Volume 2) Symptoms of infection may be seen generally at the time of flowering. All floral parts are converted into green leaf-like structures. The infected plants become partially or totally sterile, depending on the time of infection. (Courtesy of B. Sreenivasulu, Tamil Nadu Agricutlural University, Coimbatore, India) Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)
Dedicated to the Memory of my Parents for their Love and Affection
wwww
Preface
Existence of prokaryotes including bacteria has been recorded several billions of years ago. However, bacteria were demonstrated to be the causative agents of plant diseases only in the last quarter of the 19th century. Now numerous plant diseases are known to be due to the bacterial pathogens which induce symptoms distinct from those induced by fungal pathogens. Diseases caused by phytoplasmas were considered earlier to be due to viruses, because of the similarities in the modes of transmission of these two pathogenic groups. But visualization of plemorphic bodies without cell wall in the phloem tissues of the infected plants indicated the nature of the causative agents and provided evidence that phytoplasmas are related to bacteria and lack cell walls that are present in bacteria. As the bacteria and phytoplasmas are much smaller than the fungal pathogens, more powerful light microscopes and electron microscopes have to be employed for the detection and differentiation of these disease-causing agents. As the morphological characteristics have limited value for the differentiation of bacterial species, several biochemical tests have to be performed for the detection and identification of bacterial species causing the newly observed disease(s). The phytoplasma, on the other hand, have not been successfully cultured in cell-free media and hence, their cultural characteristics could not be studied. The biochemical tests are time-consuming, labor-intensive and often yield inconsistent results. It is essential that
Data Loading...
