Breeding of Carnations (Dianthus caryophyllus L.) for Long Vase Life and Rapid Decrease in Ethylene Sensitivity of Flowers after Anthesis

Abstract

Genetic improvement of flower vase life is an important breeding target. A breeding program aimed to improve the vase life of carnations (Dianthus caryophyllus L.) that carried out by repeatedly crossing and selecting promising progenies was effective. Thus, we developed many carnation lines with extremely long vase life by using the conventional cross-breeding technique. Selected lines from second-, third-and fourthgeneration have vase lives that are 2.7 to 4.1 times longer than the control cultivar, 'White Sim'. The mean vase life of line 108-44 was 23.6 days in 2003 and 19.1 days in 2004 (414% and 341% of 'White Sim' flower longevity, respectively). All selected lines showed low ethylene production in whole flowers during senescence. In addition, the petals and the gynoecia of three selected lines 908-46, 702-21, and 006-13, produced only trace amounts of ethylene during senescence, indicating that the ethylene biosynthesis pathway in these lines was almost completely blocked during senescence. Although ethylene sensitivity of the selected lines was generally high on day 0, immediately after harvesting, ethylene sensitivity after anthesis rapidly decreased with age in the three selected lines. These lines became completely ethylene-insensitive or showed low sensitivity at the end of senescence. Autocatalytic ethylene production by the gynoecia and petals of the three selected lines also decreased on days 3 and 6, respectively, after harvest.

Effects of Crossing and Selection for Seven Generations Based on Flower Vase Life in Carnations (<i>Dianthus caryophyllus</i> L.), and the Relationship between Ethylene Production and Flower Vase Life in the Breeding Lines

“…We selected a total of 123 lines (including 2 cultivars, 'Miracle Rouge' and 'Miracle Symphony') with improved vase life by conventional breeding techniques (Table 1). The crossing and selection resulted in dramatic alterations in the flower vase life of each generation and particularly in ethylene production of many selected lines (Onozaki et al, 2001(Onozaki et al, , 2006b(Onozaki et al, , 2011.…”

“…We then crossed and selected promising offspring with long vase life for seven generations, from 1992 to 2008, in order to improve the vase life of carnation flowers. The populations that we used in the present study were the same offspring populations over generations as reported previously (Onozaki et al, 2001(Onozaki et al, , 2006b(Onozaki et al, , 2011. Here we use the term "first generation", "second generation", "third generation", "fourth generation", "fifth generation", "sixth generation", and "seventh generation" in place of "parental generation", "first generation", "second generation", "third generation", "fourth generation", "fifth generation", and "sixth generation" described in the previous papers.…”

“…Here we use the term "first generation", "second generation", "third generation", "fourth generation", "fifth generation", "sixth generation", and "seventh generation" in place of "parental generation", "first generation", "second generation", "third generation", "fourth generation", "fifth generation", and "sixth generation" described in the previous papers. In previous studies, we described the detailed breeding process (Onozaki et al, 2001(Onozaki et al, , 2006b(Onozaki et al, , 2011.…”

“…532-6 (ultra-long vase life line), 536-36, 536-9, 536-24, 532-20, 532-13, 536-31, 535-18, 535-35, 533-1, 535-23, 536-11, 622-2, 622-18 Total 14 lines For information on the breeding process in selected lines of each generation, refer to Onozaki et al (2001Onozaki et al ( , 2006bOnozaki et al ( , 2011. Table 1.…”

“…We repeatedly crossed and selected promising offspring with long vase life for seven generations, from 1992 to 2008, in order to improve the vase life of carnation flowers (Onozaki et al, 2001(Onozaki et al, , 2006b(Onozaki et al, , 2011. In previous papers, we described the development of many carnation lines with increased vase life as a result of reduced ethylene biosynthesis achieved by crossing and selection for seven generations.…”