Graft transmissible diseases of citrus : handbook for detection and diagnosis

• Date de parution : 01/12/1900
• Editeur : Fao
• EAN : 9789251031827
• Série : (-)
• Support : Papier

• Nombre de pages : (-)
• Collection : (-)
• Genre : Sciences appliquées
• Thème : Sciences appliquées
• Prix littéraire(s) : (-)

This working handbook is designed to facilitate the detection of the major citrus graft-transmissible pathogens (CGTPs) and their associated diseases. Most aspects of detection are included. The primary object of this handbook is to enable users anywhere in the world to see or detect CGTPs,... Voir plus

This working handbook is designed to facilitate the detection of the major citrus graft-transmissible pathogens (CGTPs) and their associated diseases. Most aspects of detection are included. The primary object of this handbook is to enable users anywhere in the world to see or detect CGTPs, thereby assuring their elimination from citrus tissue. The ultimate objective is the elimination of these pathogens from propagative budwood and the establishment and maintenance of disease-free primary or foundation budwood source trees and nurseries to produce healthy, high-yielding citrus groves.


The importance of a good indexing programme as a means of identifying causal agents of transmissible diseases cannot be overemphasized. A prime responsibility of those in charge of a certification programme is the prevention of the distribution of thousands or millions of trees contaminated with pathogens via propagation of infected budwood. This handbook is an aid and guide toward reaching that goal.


Indexing may be defined as any test that will consistently confirm the presence or absence of a transmissible pathogen, or identify a disease.
The index test should be specific for the pathogen or disease.
Inoculation of plants is the primary means by which most graft-transmissible diseases of citrus are diagnosed (Table 3).
Inoculation is primarily by graft-transmission, but can al so be effected by vector or mechanical transmission. Other approaches to indexing are direct observation of the pathogen in plant cells by light or electron microscopy, by microscopic observation of inclusion bodies or gum deposits within the plant cells, by antibody-antigen reaction, by analysis of pathogen-induced chemical changes, by culturing an organism, by observation of pathogen-specific nucleic acids via polyacrylamide gel electrophoresis (PAGE) or by molecular hybridization. Other indexing techniques involve detection of physiological changes, such as in water uptake or mineral content of trees as used in testing for blight.