Description:
CN921-306 is the progenitor of CN921-515. CN921-306 is from composite crosses of over 60 sea beet (Beta vulgaris subsp. maritima) accessions with sugar beet (Beta vulgaris subsp. vulgaris). Individual plants of 3921-306 were selfed, and one line, 5921-306-515, was selected based on greenhouse and field trials for sugar beet cyst nematode, powdery mildew, and rhizomania. 5921-306-515 was increased and designated 7921-515, which was released as CN921-515.