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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #307972
Title: Lab testing

Author
item GOLINO, DEBORAH - University Of California
item VASQUEZ, STEPHEN - University Of California
item LEAVITT, GEORGE - University Of California
item Baumgartner, Kendra

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 6/15/2013
Publication Date: 10/15/2013
Citation: Golino, D.A., Vasquez, S.J., Leavitt, G.M., Baumgartner, K. 2013. Lab testing. In: Bettiga, L., editor. Grape pest management. 3rd edition. Oakland, CA: University of California, Division of Agriculture and Natural Resources. p. 61-68.

Interpretive Summary: Some grapevine diseases can be identified easily in the field by signs of the pathogen, which include microscopic and macroscopic microbial cells, tissues, and structures. For example, the appearance of the powdery mildew fungus on the surface of infected leaves and fruit (no microscopy needed) is quite characteristic. Some diseases, such as crown gall, are characterized by their symptoms, which are defined as abnormal plant growth caused by damage from the pathogen. In contrast, the stunted shoots, scorched leaves, or other nondescript symptoms associated with other diseases make it difficult to narrow the list of possible causes. In addition, a few diseases are identifiable only through controlled inoculations of healthy plants. Many grapevine viruses, for example, can be identified by only using a combination of lengthy biological tests and laboratory tests. To address the fact that many grapevine diseases are difficult to diagnose simply by observation of symptoms, it may be necessary under some cases to submit samples to a diagnostic laboratory for identification of the disease agent.

Technical Abstract: Some grapevine diseases can be identified easily in the field by signs of the pathogen, which include microscopic and macroscopic microbial cells, tissues, and structures. For example, the appearance of the powdery mildew fungus on the surface of infected leaves and fruit is quite characteristic. Some diseases, such as crown gall, are characterized by their symptoms, which are defined as abnormal plant growth caused by damage from the pathogen. In contrast, the stunted shoots, scorched leaves, or other nondescript symptoms associated with other diseases make it difficult to narrow the list of possible causes. In addition, a few diseases are identifiable only through controlled inoculations of healthy plants. Many grapevine viruses, for example, can be identified by only using a combination of lengthy biological tests and laboratory tests. To address the fact that many grapevine diseases are difficult to diagnose simply by observation of symptoms, it may be necessary under some cases to submit samples to a diagnostic laboratory for identification of the disease agent.