Variation in longevity of cut and in planta flowers of potted carnation varieties affected by their relationship with ethylene and water

Abstract

Carnation (<italic>Dianthus caryophyllus</italic> L.) is a typical ethylene-sensitive cut flower, but a few differences in ethylene sensitivity have been reported for different potted carnation species. In this study, we investigated the relationship between vase life, ethylene sensitivity, ethylene biosynthesis gene expression, and flower volatile substance content of 17 different potted carnation varieties. It was found that under the same post-harvest environmental conditions, the vase life of different varieties ranged from 6.2−14.2 d. Among the 17 varieties, 'Cherry' and 'Grace Bay' were highly sensitive to ethylene, and qRT-PCR analysis showed that their ethylene biosynthesis genes <italic>DcACS1</italic> and <italic>DcACO1</italic> expression increased the most, while 'Pink and Purple', 'Bondi Beach', and 'Grane Beach' showed the opposite pattern. In addition, the lower ethylene release was important in leading to longer vase life of potted carnations, and that ethylene release from shorter vase life varieties was 2.5−4.5 times greater than that of longer vase life varieties. Varieties that are more sensitive to ethylene are more likely to have a shorter vase life due to early disruption of water relations, which is mainly the result of reduced stem hydraulic conductivity and transpiration water loss. Analysis of volatile substances showed that ethylene had no significant effect on the release of volatile substances from potted carnations. Therefore, a better understanding of petal senescence in potted carnations will help us to improve measures to extend flower longevity according to the ethylene sensitivity of different varieties.