Author
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Ehlenfeldt, Mark |
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STRETCH, ALLAN - RETIRED USDA-ARS |
Submitted to: International Society of Horticultural Science Proceedings
Publication Type: Proceedings Publication Acceptance Date: 3/15/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Loss of yield to disease is a primary concern to blueberry growers. A primary objective of the USDA blueberry breeding program has been identifying sources of disease resistance to fungal diseases. A large collection of highbush blueberry cultivars has been screened for resistance to mummy berry blight, mummy berry fruit-rot, and anthracnose fruit-rot. Using common standards across years, multiple mummy berry blight screenings have been combined to allow a ranking of highbush cultivars. A large collection of rabbiteye blueberry cultivars has been similarly screened. Overall resistance to blighting was lower in rabbiteye than in highbush. Mummy berry fruit-rot resistance screening has been completed on 68 cultivars. Screenings of species have identified excellent sources of resistance to the two phases of mummy berry with V. boreale and V. myrtilloides notable for excellent resistance to both phases. Anthracnose screening of 87 highbush cultivars has shown varying resistance levels with 'Elliott' being the most resistant. Screening results are being used to compile an information base incorporating disease resistance, firmness, antioxidant levels, flowering time, and ripening time. This information should be of use to growers interested in better management of disease problems in the field, and blueberry breeders interested in developing disease resistant cultivars. Technical Abstract: A primary objective of the USDA breeding program has been identifying sources of disease resistance to fungal diseases. A comprehensive collection of highbush blueberry cultivars has been assembled and screened for resistance to mummy berry blight, mummy berry fruit-rot, and anthracnose fruit-rot. Utilizing common standards, results from multiple mummy berry blight screenings have been interpolated to allow a ranking of highbush cultivars. A large collection of rabbiteye cultivars has been similarly screened, and although differences in resistance were found, no exceptional blight resistance, similar to highbush, was identified. Mummy berry fruit rot resistance screening has been completed on 68 cultivars. Species screenings have identified excellent sources of resistance to the two phases of mummy berry with V. boreale and V. myrtilloides notable for excellent resistance to both phases. High density nurseries are being utilized for routine screening for mummy berry resistance among breeding program progenies. Anthracnose screening of 87 highbush cultivars and has shown varying resistance, with 'Elliott' being the most resistant. Effectiveness of field screening for anthracnose resistance is currently being evaluated. Screening results are being used to build a database incorporating disease resistance, firmness, antioxidant levels, flowering time, and ripening time. |