Submitted to: Crop Science
Publication Type: Germplasm Release
Publication Acceptance Date: March 31, 2000
Publication Date: N/A
Interpretive Summary: This is a Germplasm Release, no Interpretive Summary Required.
Technical Abstract: Sugarbeet (Beta vulgaris L.) germplasm line C69 was developed by the USDA- ARS in cooperation with the Beet Sugar Development Foundation and the California Beet Growers Association. This line was released in 1997. C69 is a vigorous multigerm, self-sterile line with tolerance to virus yellows (VY) and segregates for resistance to rhizomania conditioned by Rz allele. Tolerance to VY is to beet western yellows, beet chlorosis, and beet yellows viruses, but resistance to the luteoviruses, beet western yellows and beet chlorosis, is stronger. The VY tolerance was derived from nearly the entire germplasm base of the long term USDA-ARS VY resistance breeding program at Salinas, CA. Preliminary tests show that C69 has relatively high sucrose concentration, good root and agronomic traits, large canopy, and combined disease resistance. Segregation for reaction to rhizomania occurs. This line has high resistance to Erwinia and moderate resistance to VY and powdery mildew. In tests under VY inoculated conditions, C69 ha higher sugar yield than any breeding line or commercial hybrid in the trials. It is a moderately nonbolting type. Line C69 is moderately susceptible to curly top virus. Line C69 should be useful as a broadbased source for continued population improvement and from which parental lines with combined resistance could be extracted.