Submitted to: Fruit Varieties Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 1, 1997
Publication Date: N/A
Interpretive Summary: A fungal disease called white pine blister rust needs both a susceptible pine and a susceptible currant or gooseberry plant to complete its lifecycle. We grow many currants and gooseberries in Corvallis, OR. Some of these plants become infected with rust. We wished to know which currants and gooseberries are resistant to this disease. We observed 57 species of currants and gooseberries in Corvallis, OR from August through October of 1995 and 1996. We checked the undersides of leaves to see if the orange fruiting bodies (uredia) of the fungus were present. We observed that 23 species were infected either one or both years; 34 had no infection either year. The resistant species could be used by breeders to develop new resistant commercial fruit cultivars. The resistant black currant, red currant and gooseberry clones may be considered for planting in states that do not want to increase the amount of rust infection.
Technical Abstract: White pine blister rust (WPBR), Cronartia ribicola Fischer, causes economic damage to white pines, Pinus strobus L., and infects leaves of some Ribes late in the summer after harvest. Susceptible Ribes and Pinus serve as obligate alternate hosts for this disease. The objective of this study was to determine the response of Ribes species and cultivars to WPBR under field conditions at Corvallis, OR, where inoculum is naturally present. I 1995 and 1996, 57 Ribes taxa from North and South America, Europe, and Asia, were visually evaluated August through October for the presence of uredia on the abaxial leaf surfaces. Plants with no observable uredia for the duration of the study were considered resistant. WPBR infection varied by year, within taxonomic sections, and between and within species. Uredia of WPBR were present on 23 Ribes taxa in one or both years, while 34 others were resistant, i.e., had no uredia. Some of the resistant Ribes species were native outside of eastern Russia, which is the native range of the rust. Resistant species may contain new sources of genes for developing additional rust-resistant commercial fruit cultivars. The cultivation of resistant Ribes is an alternative to consider where state statutes banning the genus are under review.