- 著者
- Takayuki Mizuno Naoko Fukuta Hiroko Shimizu-Yumoto
- 出版者
- 一般社団法人 園芸学会
- 雑誌
- The Horticulture Journal (ISSN:21890102)
- 巻号頁・発行日
- pp.OKD-001, (Released:2016-08-03)
- 被引用文献数
- 8
Double-flowered Eustoma, a popular cut flower, sometimes shows nonuniform coloration of its petals when harvested at the flower bud stage. At the tips of the petals, pale greenish areas remain after the flowers open. This considerably reduces the value of cut Eustoma. In this study, to identify appropriate postharvest treatments leading to normal coloration of these cut flower buds, we investigated the influence of harvest stage, temperature, sugar, and methyl jasmonate (MeJA) on petal coloration using the Eustoma ‘Voyage (Type II) Blue’. Investigation of the harvest stage, which was compared at three flower bud stages (STG2, 3, and 4), revealed that detached pale greenish flower buds (STG2 and 3) had a high probability of becoming nonuniformly colored flowers, so these stages were used for subsequent investigations. Temperature, which was investigated at 20, 25, 30, and 35°C, did not show any influence on petal coloring. Investigation of sugar treatments, such as 1% or 3% glucose or sucrose, also showed no influence. However, MeJA treatment led to a significant difference in petal coloration. The nonuniform coloration of petals was reduced by continuous exposure to MeJA vapor. Furthermore, we performed shorter MeJA treatments, such as for 1 or 2 days after harvesting, which reduced the nonuniform coloration as well as continuous MeJA exposure. To evaluate the effect of MeJA treatment on petal coloration, we measured the rate of pale green areas of petals using digital images. The analysis revealed that the greenish areas in petals exposed to MeJA vapor were significantly smaller than in petals not exposed to MeJA. In addition, there were fewer days to flowering after MeJA treatment. We concluded that postharvest treatment with MeJA is effective for reducing nonuniform coloration of early harvested flower buds of the double-flowered Eustoma ‘Voyage (Type II) Blue’.
- 著者
- Ryo Norikoshi Katsunori Kohata Hiroko Shimizu-Yumoto Rie Goto Kazuo Ichimura
- 出版者
- 一般社団法人 園芸学会
- 雑誌
- The Horticulture Journal (ISSN:21890102)
- 巻号頁・発行日
- pp.MI-103, (Released:2016-01-13)
- 被引用文献数
- 11
Petal growth associated with flower opening is due to cell expansion. To elucidate the role of soluble carbohydrates in expansion of petal cells in Eustoma grandiflorum, its soluble carbohydrates were identified, and changes in their subcellular concentrations during flower opening were investigated. In addition to glucose, fructose, sucrose, and myo-inositol, d-bornesitol was identified using 1H-NMR. d-Bornesitol was the major soluble carbohydrate in leaves and stems. Given that cyclitols are known to be the translocated carbohydrates in alfalfa, phloem exudate was analyzed. However, the translocated carbohydrate was suggested to be sucrose, and not d-bornesitol. In the petals, glucose and sucrose content increased whereas d-bornesitol and myo-inositol contents were almost constant during flower opening. The fructose content in petals was very low. Glucose, sucrose, myo-inositol, and d-bornesitol were found mainly in the vacuole, although sucrose was also found in the cytoplasm. In the petals of open flowers, glucose and sucrose concentrations in the vacuole increased to 60 and 53 mM. Inorganic ion concentrations in the symplast and apoplast did not increase during flower opening. The osmotic potential of the symplast and apoplast in the petals was lower at the open stage than the potential of those at the bud stage, and this difference was mainly attributed to increases in glucose and sucrose concentrations. The results suggest that the accumulation of glucose and sucrose in the vacuole reduces the symplastic osmotic potential, which appears to be involved in the cell expansion associated with flower opening, but that the contribution of d-bornesitol as an osmoticum to cell expansion is limited in Eustoma.