Growth and development of aquilegia in relation to temperature, photoperiod and dry seed vernalization

A selected genome pool of commercial cultivars and genetic lines of Aquilegia x hybrida were grown in greenhouses and evaluated for their growth and flowering responses to temperature, photoperiod and dry seed vernalization. 'Blue Shades', 'Pink Shades', 'Blue-White', 'Rose-White' and 'White' flowered 4-5 months from sowing when grown at 9-13 degrees C night temperature. Day temperatures of 16-19 degrees C induced earlier flowering than day temperatures >24 degrees C. Commercial cultivars 'Blue Jay', 'Dove', 'Musik-Blue-White' and 'Musik-Red-White' did not flower during these studies. Higher crown number per plant was correlated with lower day temperatures. Dry seed vernalization at 4 degrees C induced slightly earlier flowering in 'Blue-White' and 'Rose-White'. Extending the photoperiod to 14 h in the early phases of the growth cycle delayed flowering. Certain genetic lints of aquilegia may be suitable for spring forcing if the seed is vernalized and plants are grown at night temperatures of 9-13 degrees C. (C) 1997 Elsevier Science B.V.