THE UTILITY OF THE FIREBLIGHT TOXIN, AMYLOVORIN, FOR THE DETECTION OF RESISTANCE OF APPLE, PEAR, AND QUINCE TO ERWINIA AMYLOVORA

The production of a toxin by Erwinia amylovora was initially detected in bacterial ooze by Hildebrand (1939). Subsequently, Goodman et al. (1974) described some of the characteristics of the toxin and gave it the trivial name of amylovorin.
Their data indicated that sensitivity of certain rosaceous cultivars to the toxin paralleled their susceptibility to the pathogen.
As a consequence they suggested that amylovorin might be useful to apple and pear breeders in detecting fireblight resistant accessions.
The utility of amylovorin in evaluating the resistance to fireblight in material from breeding programs has been challenged by Sjulin and Beer (1976) as well as Beer and Aldwinkle (1976). Nevertheless, subsequent studies by Hsu and Goodman (1978) as well as Stoffl, Karr, and Goodman (1976) could detect no departure from the previously reported wilt activity of amylovorin against rosaceous species or its capacity to distinguish highly resistant from highly susceptible cultivars.
The initial studies of Goodman et al. (1974) were limited to three apple, seven pear, and five quince cultivars.
The investigation described herein evaluates the sensitivity of eight apple, seven pear, and four quince cultivars.
Optimum environmental conditions for the bioassay were initially established by Stoffl (1976).

Symposium on Fire Blight

R.N. Goodman, P.R. Stoffl, Sandra M. Ayers

https://doi.org/10.17660/ActaHortic.1978.86.8