Genetic improvement of vase life of carnation ̄owers by crossing and selection

We used conventional cross-breeding techniques to develop many carnation lines with long vase life and either low ethylene production or low ethylene sensitivity. Two cycles of selection and crossing to improve vase life led to a 3.6-day increase in mean vase life. All 39 selected lines had signi®cantly longer vase life than the control cultivar, `White Sim'. In particular, second-generation lines 63-3, 63-12, 66-15, and 63-41 had a mean vase life of more than 15 days without chemical treatment. Measurements of ethylene production indicated that ̄owers of all second-generation selected lines had a greatly reduced capacity to produce ethylene. We screened three lines (515-10, 64-13, and 64-54) with low ethylene sensitivity. Evaluation by exposure to ethylene at high concentration showed that 64-13 and 64-54 were less sensitive to ethylene than `Chinera', which is known for it low sensitivity. The vase life of these low-sensitivity lines was about twice that of `White Sim'. The extended vase life of selected lines was related to low ethylene production at ̄ower senescence rather than to degree of ethylene sensitivity in young ̄owers. Ethylene sensitivity decreased with the age of the ̄ower in many selected lines. The results clearly show that vase life of carnation ̄owers can be extended by crossing and selection. # 2001 Elsevier Science B.V. All rights reserved.