Color profile: Disabled Composite Default screen 1Landmarks in Plant Pathology Landmarks in Plant Pathology 1 Early Recognition of Plant Diseases c. 300 BC Theophrastus of Lesbos – references to plant diseases in Historia plantarum and De causis plantarum. c. AD 50 Caius Plinius Secundus – references to common diseases such as mildew and rusts of cereals in Historia naturalis. c. AD 700 Cassianus Bassus – Geoponica – a compilation of Byzantine agriculture with many references to plant diseases. c. AD 1200 Ibn-al Awam – Kitab al-Felahah – Arabic treatise from Seville with a chapter on problems of regional fruit crops. Beginnings of Plant Pathology 1665 Robert Hooke – Micrographia contains first illustration of a microscopic plant pathogen (rose rust). 1755 Mathieu Tillet demonstrates seed-borne nature of wheat bunt (Tilletia caries). 1794 J.J. Plenk publishes Physiologia et Pathologia Plantarum con- taining a classification of plant diseases based on symptoms. 1802 William Forsyth introduces lime sulphur for control of mildew on fruit trees – first example of generally used fungicide. 1807 I.-B. Prevost publishes first experimental proof of fungal patho- genicity on plants. 1845–1849 Potato blight (Phytophthora infestans) epidemics in Ireland. CAB International 2002. Plant Pathologist’s Pocketbook (eds J.M. Waller, J.M. Lenné and S.J. Waller) 1 11 Z:\Customer\CABI\A4084 - Waller - Plant Pathologists Pocketbook\A4163 - Waller - Plant - All.vp Monday, October 29, 2001 4:37:47 PM Color profile: Disabled Composite Default screen 2 Landmarks in Plant Pathology 1853 Anton de Bary publishes Unterschungen über die brandpilze and established the role of fungi as plant pathogens. 1858 Julius Kuhn publishes Die Krankheiten der Kulturgewachse – the first plant pathology text. 1865/66 De Bary demonstrates heteroecism in Puccinia graminis. 1868–1882 Coffee rust (Hemileia vastatrix) epidemics in Sri Lanka and classic studies on its aetiology by Marshal Ward. 1874 Paul Soraur publishes first edition of Handbuch für Pflanzen- krankheiten of which there have been many subsequent editions. 1878–1885 Vine downy mildew (Plasmopara viticola) epidemics in France precipitate introduction of Bordeaux mixture by Millardet. 1885 J.C. Arthur provides first proof of bacterial pathogenicity to plants with fire blight (Erwinia amylovora). 1886–1898 Tobacco mosaic recognized as a virus disease transmitted by ‘contagious living fluid’ by Mayer, Ivanovski and Beijerinck. 1889 Hot water treatment of seed introduced for control of loose smut of wheat (Ustilago tritici). Development of Basis for Modern Plant Pathology 1891/92 First plant pathology journals (Zietschrift für Pflanzenkrank- heiten and Revista di Patologia Vegetale) published. 1894 Jacob Eriksson demonstrates host-specific special forms of cereal rusts. 1904 Rowland Biffen demonstrates Mendelian inheritance of resistance to rust in cereals. 1907 First university department of plant pathology founded at Cornell University, New York. 1908 American Phytopathology Society founded. 1913 Recognition of physiologic races of Puccinia graminis by Stakman. First use of organo-mercurial fungicides for seed application in Germany. 1914 First ‘International Phytopathological Convention of Rome’ held but resolutions never ratified. 1920 Imperial Bureau of Mycology founded in UK(a forebear of CABI Bioscience) – production of Review of Plant Pathology (as Review of Applied Mycology) commences 2 years later. E.F. Smith publishes Introduction to Bacterial Diseases of Plants. 1929 ‘International Convention for the Protection of Plants’ in Rome produces first limited internationally agreed protocols for restricting the spread of plant diseases. 1934 Dithiocarbamate fungicides developed and patented by Du Pont. 1937 F.C. Bawden and N.W. Pirie establish nucleoprotein nature of viruses. 12 Z:\Customer\CABI\A4084 - Waller - Plant Pathologists Pocketbook\A4163 - Waller - Plant - All.vp Monday, October 29, 2001 4:37:47 PM Color profile: Disabled Composite Default screen Landmarks in Plant Pathology 3 1946 Flor establishes ‘gene-for-gene’ hypothesis for genetic inter- action of resistance and virulence for flax rust Melampsora lini. 1951 European and Mediterranean Plant Protection Organization founded as first of several regional plant protection organizations. 1952 International Plant Protection Convention submitted to the Food and Agriculture Organization (FAO) and agreed in principle. 1963 Annual Review of Phytopathology begins. J.E. Vanderplank publishes Plant Diseases: Epidemics and Control. First example of biological control of a disease – Heterobasidion annosum by Peniophora gigantea. 1965 Discovery of first systemic fungicide, carboxin. 1967 First recognition of phytoplasmas (mycoplasma-like organisms) as plant pathogens. 1968 First International Congress of Plant Pathology held in London. 1969 First computer simulation program for plant disease epidemics. 1970 Southern corn leaf blight epidemic on hybrid (Tms) maize in USA. 1971 Deiner establishes potato spindle tuber as first recognized viroid disease. 1977/78 Plant Disease: An Advanced Treatise (3 Vols) by Horsfall and Cowling published. 1986 Plants genetically transformed to express virus coat proteins shown to be resistant to same virus. 1992 First examples of plant resistance genes isolated. General References Ainsworth, G.C. (1981) An Introduction to the History of Plant Pathology. Cambridge University Press, Cambridge, UK, 315 pp. Carefoot, G.L. and Sprot, E.R. (1967) Famine in the Wind. Rand McNally, Chicago, USA. Large, E.C. (1940) Advance of the Fungi. Jonathan Cape, London, UK, 488 pp. Parris, G.K. (1968) A Chronology of Plant Pathology. Johnson & Sons, Mississippi, USA. 13 Z:\Customer\CABI\A4084 - Waller - Plant Pathologists Pocketbook\A4163 - Waller - Plant - All.vp Tuesday, October 30, 2001 3:08:08 PM Color profile: Disabled Composite Default screen 10BacteriaG. Saddler and Plant Disease Bacteria and Plant Disease 10 G. Saddler CABI Bioscience UK Centre, Bakeham Lane, Egham, Surrey TW20 9TY, UK Introduction Bacteria are ubiquitous and physiologically diverse; those that are found in association with plants exist as epiphytes, endophytes and pathogens. Phytopathogens, members of the latter group, are relatively few in both type and number (Kado, 1992; Sigee, 1993). All bacterial phytopathogens described to date fall within the Domain Bacteria (formerly known as the Eubacteria). Most possess common morphological characteristics, namely, straight or slightly curved rods with rigid cell walls and aerobic or facultatively anaerobic metabolism. An exception to this rule are members of the Class Mollicutes, which, though related to Gram-positive bacteria such as clostridia and bacilli, lack a rigid cell wall. These organisms are dealt with separately in Chapter 12. Bacterial phytopathogens possessing a cell wall can be subdivided into Gram-positive and Gram-negative. These groupings, based on a well- established microscopy stain, roughly equate with the more recent phylo- genetic treatment of bacteria. In this regard, all Gram-negative bacterial plant pathogens are encompassed within the Class Proteobacteria (Stackebrandt et al., 1988) whilst the Gram-positives are recovered in Class Actinobacteria (Stackebrandt et al., 1997). Most phytopathogenic bacteria are Gram-negative, the majority of which belong to the genera Acidovorax, Agrobacterium, Burkholderia, Enterobacter, Erwinia, Pantoea, Pseudomonas, Ralstonia and Xanthomonas (Table 1). The few Gram-positive pathogens are mainly contained within the genera Clavibacter, Curtobacterium, Rathayibacter and Streptomyces. For detailed information on many bacterial phytopathogens see Bradbury (1986). CAB International 2002. Plant Pathologist’s Pocketbook 94 (eds J.M. Waller, J.M. Lenné and S.J. Waller) 104 Z:\Customer\CABI\A4084 - Waller - Plant Pathologists Pocketbook\A4163 - Waller - Plant - All.vp Monday, October 29, 2001 4:38:08 PM Color profile: Disabled Composite Default screen Bacteria and Plant Disease 95 Table 10.1. The major types of plant-pathogenic bacteria. Genus/species General disease symptoms Gram-negative bacteria Acetobacter spp. Pink disease of pineapple fruit Acidovorax spp. Leaf blight, leaf spots/streak Agrobacterium spp. Crown gall, hairy root formation Burkholderia spp. Vascular wilts, rots Enterobacter spp. Cankers, leaf spots and rots Erwinia spp. Vascular wilts, dry necroses, leaf spots and soft rots Gluconobacter oxydans Pink disease of pineapple fruit Pantoea spp. Vascular wilts, rots Pseudomonas spp. Leaf spots, vascular wilts, soft rots Ralstonia spp. Vascular wilts Rhizobacter daucus Bacterial gall of carrot Serratia marcescens Crown and root rot of lucerne Xanthomonas spp. Leaf spots, vascular wilts, stem cankers Xylella fastidiosa Pierce’s disease of grape Xylophilus ampelinus Bacterial blight of grape Gram-positive bacteria Arthrobacter ilicis Holly bacterial blight Clavibacter spp. Vascular wilts, cankers Curtobacterium spp. Silvering disease, vascular wilts Nocardia vaccinii Blueberry gall Rathayibacter spp. Gumming disease Rhodococcus fascians Leafy gall Streptomyces spp. (S. scabies) Potato scab Significant Bacterial Plant Pathogens Gram-negative genera Acidovorax This is a member of the family Comamonadaceae in the β-subdivision of the class Proteobacteria. Members of this genus were formerly assigned to the genus Pseudomonas. The genus Acidovorax was created after extensive taxonomic studies indicated a number of species were quite distinct from the genus Pseudomonas