Breeding of carnations (Dianthus caryophyllus L.) for long vase life

Abstract

Carnation (Dianthus caryophyllus L.) is one of the main floricultural crops in Japan and worldwide. The vase life of cut ornamental flowers, including carnations, is important in determining their quality and consumers' preference. To improve the vase life of carnation flowers, my group started a breeding research program in 1992 using conventional cross-breeding techniques. We repeatedly crossed and selected promising offspring with long vase life for seven generations, from 1992 to 2008. In 2005, we developed two cultivars, 'Miracle Rouge' and 'Miracle Symphony', with genetically determined long vase lives of 17.7 to 20.7 days (3.2 to 3.6 times that of 'White Sim') under standard conditions (23°C, 70% RH, 12-h photoperiod). Line 532-6 showed an ultra-long vase life averaging 27.8 to 32.7 days (4.6 to 5.4 times that of 'White Sim'). We evaluated changes in ethylene sensitivity with flower senescence simply and accurately using a time-lapse video recorder. In 2010, we selected line 806-46b with both ultra-long vase life (27.1 days, 4.4 times that of 'White Sim') and ethylene resistance. Analyses using six cultivars and 123 selected lines from the 1st to the 7th generations revealed that the long vase life was strongly associated with a decrease in ethylene production.

Keywords: carnation; ethylene production; ethylene sensitivity; flower longevity; flower senescence.

Fig. 1

(A) Six parental cultivars used as initial breeding materials. (B) Frequency distributions of vase life in 1st to 7th generations. Vertical bars represent means. (C) Selection of ‘Miracle Symphony, ‘Miracle Rouge’, line 108-44, and line 532-6.

Fig. 2

Evaluation method and selection procedure for the improvement of vase life.

Fig. 3

Variation in the vase life of (A) ‘Miracle Rouge’, (B) ‘Miracle Symphony’, and control cultivars 18 days after harvest. The flowers were held in distilled water under standard conditions (23°C, 12-h photoperiod, 70% RH). A: Left to right, ‘Nora’, ‘Miracle Rouge’, ‘White Sim’. B: Left to right, ‘White Sim’, ‘Miracle Symphony’, ‘Scania’.

Fig. 4

Changes in ethylene production from petals and gynoecia of four cultivars during senescence. Values represent means ± SE of the data of five replications.

Fig. 5

Variation in the vase life of 7th-generation line 532-6 with ultra-long vase life and two control cultivars, ‘Miracle Rouge’ and ‘White Sim’ at (A) 25 days and (B) 26 days after harvest. A: Left to right, ‘Miracle Rouge’, 532-6, ‘White Sim’. B: Left, ‘Miracle Rouge’; right, 532-6.

Fig. 6

Variation in sensitivity to ethylene (10 μL L⁻¹) among (upper left) ‘Nora’ (control), (lower left) 004-17 (highly sensitive), (upper right) 64-54 (resistant), and (lower right) 234-36S (resistant) at (A) 0 h, (B) 8 h, and (C) 48 h after treatment began.

Fig. 7

Effect of cut flower age at treatment time on sensitivity to ethylene (10 μL L⁻¹) of ‘Miracle Symphony’ at (A) 0 h, (B) 10 h, and (C) 72 h after treatment began. Left: exposed immediately after harvest. Right: exposed 18 days after harvest.

Fig. 8

(A) Variation in the vase life of line 806-46b with ultra-long vase life and three control cultivars, 35 days after harvest. The flowers were held in distilled water under standard conditions (23°C, 12-h photoperiod, 70% RH). Left to right: ‘Miracle Symphony’, ‘Miracle Rouge’, 806-46b, ‘Excerea’. (B) Variation in sensitivity to ethylene (10 μL L⁻¹) between (left) ‘Karen Rouge’ (sensitive) and (right) 806-46b (resistant) at 12 h after treatment began.

Fig. 9

Relationships between vase life and (A) ethylene production at natural senescence, (B) ethylene production after ethylene treatment, (C) response time to ethylene treatment, and (D) flower diameter. **Significant at 1% level; N.S.: not significant. In C, response time to ethylene treatment in 1st-generation lines was not measured, because we had not established our video evaluation method (Onozaki et al. 2004a) before 2001.