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United States Department of Agriculture

Agricultural Research Service

Research Project: PHYSIOLOGICAL AND GENETIC BASIS OF POSTHARVEST QUALITY, DISEASE CONTROL, AND PHYTONUTRIENT CONTENT OF SELECTED FRUITS AND VEGETABLES Title: On the reliability of Fusarium oxysporum f. sp. niveum research: Do we need standardized testing methods?

Authors
item Bruton, Benny
item Fish, Wayne
item Vivoda, Elisabetta -
item Gabor, Brad -
item Sandlin, Craig -
item Everts, Kathryne -

Submitted to: Cucurbitacea
Publication Type: Proceedings
Publication Acceptance Date: August 9, 2010
Publication Date: November 14, 2010
Citation: Bruton, B.D., Fish, W.W., Vivoda, E., Gabor, B., Sandlin, C., Everts, K.L. 2010. On the reliability of Fusarium oxysporum f. sp. niveum research: Do we need standardized testing methods? In: Cucurbitaceae 2010 Proceedings, November 14-18, 2010, Charleston, South Carolina. p. 222-225.

Interpretive Summary: Fusarium wilt of watermelon is widespread in watermelon-growing regions of the world, and frequently is the major factor limiting watermelon production. The causal agent is the fungus Fusarium oxysosporum f. sp. nivium (Fon). Isolates of Fon vary in aggressiveness from weakly to highly aggressive and this trait constitutes a continuum rather than distinct separation into races. In spite of the recognition of this continuum of aggression, attempts to quantify Fon isolates have led to partitioning isolates into one of four races (0, 1, 2, and 3). Unfortunately, race designations for Fon isolates are frequently based on imprecise methodologies and the fact that a better method has not been forthcoming. Although it has been suggested that methods for identifying races of Fon and resistance in watermelon be standardized, little progress has been made over the last 50 years. Inoculation parameters (greenhouse temperature, inoculum concentration, inoculation method, and plant stage) are extremely important and most are critical for accurately identifying Fon races and genetic resistance in watermelon.

Technical Abstract: Fusarium oxysporum f. sp. nivium (Fon) is a pathogen highly variable in aggressiveness that requires a standardized testing method to more accurately define isolate aggressiveness (races) and to identify resistant watermelon lines. Isolates of Fon vary in aggressiveness from weakly to highly aggressive and this trait constitutes a continuum rather than distinct separation into races. In spite of the recognition of this continuum of aggression, attempts to quantify Fon isolates have led to partitioning isolates into one of four races (0, 1, 2, and 3). Unfortunately, race designations for Fon isolates are frequently based on imprecise methodologies and the fact that a better method has not been forthcoming. Inoculation parameters (greenhouse temperature, inoculum concentration, inoculation method, plant stage) are extremely important and most are critical for accurately identifying Fon races and genetic resistance in watermelon.

Last Modified: 8/27/2014
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