Abstract
Abstract Reactions of 122 apple clones, representing 26 pure and hybrid species of Malus, to Erwinia amylovora (Burrill) Winslow et al. were evaluated in the greenhouse, orchard, and field nursery. Vigorously growing shoots, 7 to 9 weeks old, were tip inoculated by injecting a 24-hour broth culture of a highly pathogenic isolate of E. amylovora. Lesion development, measured 5 to 7 weeks after inoculation, was expressed as a percentage of the current season’s shoot length killed by fire blight. Inter- and intraspecific variation in resistance, similar to that reported for Pyrus, was observed. The highest level of resistance, typified by a small necrotic lesion 2-3 mm in diameter around the inoculation point, occurred in small-fruited selections derived from Asiatic species. Few selections of the cultivated apple, Malus pumila Mill., were resistant. Fire blight ratings were assigned the clones based on their potentials as parents for breeding apple rootstocks.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the American Society for Horticultural Science
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
