Description:
C23BM was developed from a broad base of Beta vulgaris subsp. maritima accessions from the North Atlantic. Most of these had been collected by DL Doney. From tests to evaluate these accessions for resistance to BNYVV, resistant plants were selected and intercrossed to produce germplasm lines R423 (PI 599350), R423B (PI 599351), and R720 (PI 599352). R423 was a composite cross from PIs of B. maritima in the 518000-518400 range; R423B in the PI 518408-540610 range; and R720 mostly from France. Following repeated mass selections for resistance to rhizomania, virus yellows, and other diseases, the three component lines were selected for resistance to resistance breaking strain of BNYVV and combined to produce R723Bmv. R723Bmv was recombined to produce R823Bmv being stored as C23BM.