Genetic variation in Jerusalem artichoke (Helianthus tuberosus L.) flowering date and duration

Abstract

Increased interest in the Jerusalem artichoke (Helianthus tuberosus L.) stems from the high level of inulin, a straight chain fructan, found in the tubers that has a number of current and potential industrial applications. Deficiencies in existing cultivars have underscored the need for a pragmatic breeding program. Since synchronization of flowering has a pronounced influence on genetic crosses that can be made, we assessed the flowering date and duration of 190 clones with selected clones similarly monitored for two additional growing seasons. Substantial genetic variation in the date and the duration of flowering were found with the onset of flowering ranging from 69 to 174 days after planting (DAP). Flowering duration ranged from 21 to 126 days. The onset of flowering was substantially affected by planting date and to a lesser extent by location. The results suggest that at lower latitudes flowering date for some clones can be manipulated by planting date; at higher latitudes, growth under controlled conditions may be required to synchronize flowering of some clones.