Inheritance of annual habit in celery: cosegregation with isozyme and anthocyanin markers.

Vernalization response was determined in an annual and two biennial celery strains, Apium graveolens L. and their F2 hybrids. Although the annual strain did not require vernalization to bolt, plants exposed to 10°C for 7 days bolted 2 weeks earlier than non-treated plants. Inheritance studies based on F2 and backcross segregations demonstrate that annual habit in celery is partially dominant over biennial and determined by a single gene designated Hb. Cosegregation studies of this trait with nine isozyme loci and a gene determining petiole anthocyanin pigmentation disclosed the following linkage relationships: Adh-1-Sdh-1-Mdh-1, and Got-1-Mdh-2-Hb-A. The recombination frequency observed for Hb and Mdh-2 was too large to use the latter as a useful marker for annual habit.