Development of dahlia cultivars‘Eternity Torch’‘, Eternity Romance’ and‘Eternity Rouge’with long vase life

Abstract

The vase life of cut ornamental flowers, including dahlias, is important breeding target in determining their quality and consumers’ preference. Therefore, we initiated a research breeding program in 2014 to improve the vase life of dahlias. We chose 22 commercial cultivars as initial breeding materials, and repeatedly crossed and selected promising offspring with long vase life for two generations, from 2014 to 2016. Three lines, 505-13, 629-18 and 606-46, were judged to be the most suitable as new cultivars with long vase life. We registered these cultivars with Japan’s Ministry of Agriculture, Forestry and Fisheries and released them as ‘Eternity Torch’, ‘Eternity Romance’ and ‘Eternity Rouge’. These three new dahlia cultivars had genetically determined long vase lives of 6.3 to 12.0 days (1.4 to 2.2 times the vase life of a standard cultivar, ‘Kamakura’) in distilled water, 9.0 to 13.4 days (1.1 to 2.0 times the vase life of ‘Kamakura’) in GLA (10 g·L^-1 glucose, 0.5 ml·L^-1 kathon CG, and 50 mg·L^-1 aluminum sulfate) under 23 °C, 12-h photoperiod, and 70% RH conditions in 2018 and 2019. Cut flowers cultivated at five locations nationwide with different cultivation seasons in 2019 also showed similar long vase life, clearly indicating that the long vase life of our three cultivars were not due to the environment but the characteristics of cultivars.