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ARS Home » Research » Publications at this Location » Publication #98603
Title: PUTATIVE SOURCES IN STRAWBERRY FOR RESISTANCE TO BACTERIAL ANGULAR LEAFSPOT

Author
item Maas, John
item GOUIN BEHE, CRISTINA
item Hartung, John
item Hokanson, Stan

Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 8/16/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Bacterial angular leafspot disease (BALD) of strawberry, caused by Xanthomonas fragariae, has dramatically affected commercial fruit and plant production throughout the world. Leaf lesions may kill leaves, while lesions on sepals make fruit unmarketable. The bacterium can kill stolon-tip plantlets that are being rooted for transplanting. Since plants become systemically infected, there is no adequate chemical control for BALD under conditions that favor development and spread of the disease. Strawberry is the only host and no cultivars or advanced selections have proven resistant to this disease. We screened 23 Fragaria x ananassa, 13 F. chiloensis, 56 F. virginiana, and 2 F. vesca genotypes for resistance to two pathogenic isolates of X. fragariae (ATCC-33239, the original strain from Minnesota and Xf-3 from North Carolina). Leaves were inoculated by forcing bacterial suspensions into leaves under pressure with a syringe barrel and plunger. Plants were incubated in a moisture chamber for 3 days, followed by 1 week under mist and then placed on a greenhouse bench. Only two genotypes were found to show a resistant reaction: Earliglow x F. virginiana from Georgia) and an F. virginiana clone from Minnesota). Each of these genotypes exhibited typical hypersensitive responses by walling-off inoculation areas. All other genotypes exhibited typical BALD symptoms 5 weeks after inoculation with both isolates.