Cut Flower Cultivars Research Articles

Carbohydrates and Postharvest Leaf Blackening of Proteas

Glucose, fructose, sucrose, and starch concentrations were determined in leaves and inflorescences of protea cutflower cultivars soon after harvest and at the onset of leaf blackening while standing in water. At the onset of leaf blackening sugars and starch were lower in both inflorescences and leaves. Proportionately, sugars and starch decreased more in leaves than in inflorescences. Flower-bearing shoots of `Sylvia' were pulsed individually with 5% glucose solution until each shoot had taken up 10 mL solution. Water served for control treatment. Flowers were then stored for 21 days at 1 °C. After pulsing and after cold storage groups of flowering shoots were separated into inflorescence, leaf and stem components and glucose and starch content determined. Glucose content, determined upon completion of pulsing treatments, was significantly greater in all shoot components of shoots pulsed glucose compared with nonpulsed control shoots. Glucose content of leaves was significantly greater after storage for shoots pulsed than control shoots. Starch content of leaves determined upon completion of pulsing treatments was significantly greater in shoots pulsed with glucose than that of controls. There was a significant decrease in starch content for all tissue types during 21 days of storage. Pulsing flower stems of seven protea cultivars before 3 weeks cold storage significantly reduced the incidence of leaf blackening when assessed both on day 1, and again on day 7 after 3 weeks of cold storage. Supplementing holding solutions with 1% or 2% glucose reduced leaf blackening of proteas pulsed with glucose and cold stored for 3 weeks.

Direct shoot regeneration from lamina explants of two commercial cut flower cultivars of Anthurium andraeanum Hort.

Direct plant regeneration from flowering plant-derived lamina explants of Anthurium andraeanum Hort. cultivars Tinora Red and Senator was established on modified Murashige and Skoog (MS) medium. Cultivar difference, stage of source lamina and the position of explant in lamina, medium pH, and type of growth regulators significantly influenced direct plant regeneration. Explants from young brown lamina were superior to young green lamina. The half-strength MS medium containing 1.11 μM N6-benzyladenine (BA), 1.14 μM indole-3-acetic acid, and 0.46 μM kinetin at pH 5.5 was most effective for induction of shoot formation. Explants from the proximal end of the source lamina gave rise to a higher number of shoots compared to the mid and distal regions. Cultivar Tinora Red was more regenerative than Senator in terms of number of shoots per explant. The use of a lower BA concentration (0.44 μM) was essential for callus-free shoot multiplication during subculture. Regenerated shoots could be induced to form roots on half-strength MS medium supplemented with 0.54 μM α-naphthaleneacetic acid and 0.93 μM kinetin. More than 300 plantlets of each eultivar were harvested from a single source lamina within 200 d of culture. Most plantlets (95%) survived after acclimation in soil.

Linalool and linalool oxide production in transgenic carnation flowers expressing the Clarkia breweri linalool synthase gene

Most modern cut-flower cultivars, including those of carnation(Dianthus caryophyllus), lack distinct fragrance.Carnationcv. Eilat flowers produce and emit various fragrance compounds, includingbenzoic acid derivatives and sesquiterpenes, but not monoterpenes. Based onGC-MS analysis, benzoic acid, benzyl benzoate, phenylethyl benzoate, methylbenzoate, cis-3-hexenyl benzoate and β-caryophylleneare the major fragrance compounds, representing ca. 60% of the total volatilesgenerated by these flowers. The level of these compounds increases dramaticallyduring petal development. To evaluate the possibility of producing monoterpenesin carnation cv. Eilat, we generated transgenic plants expressing the linaloolsynthase gene from Clarkia breweri under the regulation ofthe CaMV 35S constitutive promoter. The product of this gene catalyzes theproduction of the monoterpene linalool from geranyl diphosphate. HeadspaceGC-MSanalysis revealed that leaves and flowers of transgenic, but not controlplants,emit linalool and its derivatives, cis- andtrans-linalool oxide. GC-MS analysis of petal extractrevealed the accumulation of trans-linalool oxide but notlinalool. The emission of linalool by the transgenic flowers did not lead todetectable changes in flower scent for human olfaction.

Thidiazuron—a potent inhibitor of leaf senescence in Alstroemeria

The time to flower senescence and leaf yellowing in 20 cut flower cultivars of Alstroemeria was studied. In deionized water (DI), the time to abscission of the first petal ranged from 9 to 16 days. Time to leaf yellowing ranged from 5 to 18 days. These two processes proceeded independently so that in some cultivars leaf yellowing occurred long before flower senescence, and in others, much later. Thidiazuron (TDZ, N-phenyl-N′-1,2,3-thiadiazol-5-ylurea), a substituted phenylurea with cytokinin-like activity, markedly extended leaf longevity. TDZ was much more effective than two other substituted phenyl-urea compounds tested, in delaying leaf yellowing. A single 24-h pulse treatment with 10 μM TDZ prevented yellowing of isolated leaves for more than 2 months.

The effects of inorganic salts and growth regulators on in vitro shoot proliferation and leaf chlorophyll content of Delphinium cardinale

In the genus Delphinium, D. cardinale is one of the more important species for breeding of cut-flower cultivars. Establishment of an in vitro shoot proliferation method of this species has been achieved. Plantlets were obtained from nodal sections of young inflorescence stalks using 5–20 μM BAP. For shoot proliferation, the ammonium-ion concentration of Murashige–Skoog medium should be reduced by one-third. The Fe-ion concentration played an important role in avoiding chlorosis of leaf blades. When the Fe-ion concentration of MS medium was doubled, chlorophyll content was 2-to-5 times higher than it was with the MS medium. Addition of 5 μM BAP increased the number of shoots. Histological observations showed that, on the hormone-free medium shoot, proliferation resulted from lateral shoot development, but on BAP-containing medium, adventitious shoot formation from basal tissue also occurred.

Breeding vandaceous orchids for commercial cut-flowers in Singapore: an overview

Extensive artificial hybridisation among members of some 86 genera of vandaceous orchids within the subtribe Sarcanthinae in Singapore over the past five decades has created many thousands of exotic hybrids. A small number of these are selected for commercial cut-flower production, while others are cultivated as pot-plants. Two classes of intergeneric hybrids are of special commercial importance as export cut-flowers, the bigeneric Aranda (Arachnis x Vanda) and the trigeneric Mokara (Arachnis x Vanda x Ascocentrum) hybrids. Cytogenetic studies of these hybrids in recent years have provided information on the significance of ploidy levels and genomic constitutions on the horticultural performance of cut-flower cultivars, and also on the strategy for effective breeding in vandaceous orchids.

Effect of Blue Light on Flowering in Dendranthema grandiflora and Diapause Induction in Orius insidiosus

Orius is an effective predatory bug of western flower thrips on chrysanthemum. However, long days are required to prevent reproductive diapause in Orius, which is counter to the short-day flowering response in Dendranthema. Two cut flower cultivars (`Manatee Iceberg' and `Naples') and a pot cultivar (`Boaldi') were given short days, long days with broad spectrum light, and long days with supplemental blue light (430–480 nm) at critical threshold levels. Blue light at intensities of 2 to 5 μmol·m–2·s–1 had no effect on flower induction, size, or dry weight or leaf dry weight compared to the short-day control. Increasing intensity and blue light exposure reduced flowering in the cut mum cultivars. At 25C, 77% of Orius females were reproductive in blue light compared to 75% in broad spectrum and 46% in short days. Spectral quality had no effect on fecundity, survival, or insect development rate. At least 90% of Orius reproduced with blue light at 19, 22, 25, and 28C. These results indicate possibilities for providing favorable conditions for biocontrol of arthropod pests on short-day crops.

Cold Storage of Selected Members of the Proteaceae and Australian Native Cut Flowers

Five members of the Proteaceae and 13 Australian native cut flower cultivars were stored for 35 days under standard conditions at 1C to assess their ability to withstand long-term storage and transport. Protea cynaroides L., Leucadendron `Silvan Red', Leucospermum `Firewheel', Thryptomene calycina (Lindl.) Stapf., Telopea speciosissima R. Br., and Verticordia grandtiflora Endl. retained a vase life of at least 7 days after 21 days of storage. Leucospermum cordifolium Salisb. ex Knight, Protea neriifoli R. Br., Chamelaucium uncinatum `Alba', C. uncinatum `Purple Pride', Verticordia monadelpha Turcz., Verticordia plumosa (Desf.) Druce, and Verticordia nitens (Lindl.) Schau. suffered a decline in vase life ranging from 31% to 100% after 14 to 21 days of storage. Species of Verticordia and Chamelaucium were particularly susceptible to fungal infection. Anigozanthos pulcherrimus Hook. and the Anigozanthos cultivars Ruby Delight, Bush Harmony, Bush Haze, and Gold Fever all showed a significant reduction in vase life after 14 days of storage compared with unstored controls.

Production of prunus necrotic ringspot virus-free roses by heat treatment and tissue culture

Abstract By a combination of heat treatment and tissue culture, virus was eliminated from 10 cut-flower cultivars and 1 rootstock cultivar. The roses, grown in hydroponics, were placed in an environmentally controlled cabinet and held at about 38°C. Heat stress occurred rapidly in all except the rootstock Rosa fortuniana Lindl. Survival time ranged from 8 to 20 days depending on the cultivar. Axillary buds removed from heattreated plants just before total collapse were established in tissue culture, but many degenerated and died after a few weeks. In one study of 1023 tissuecultured buds, only 45 survived to produce established plants in the glasshouse. In total, 79 tissuecultured plants were produced, and 62% of these were virus-free after 12 months of testing. These plants now form the nucleus of a Plant Improvement Program for roses in Victoria, Australia.

Specialty Cut Flower Production Guidelines for Florida - Zinnia

Zinnia elegans is a composite flower ranging in size from 2 to 6 inches wide on a long stem with opposite lanceolate leaves. With an upright, bushy habit, its size averages 30 inches tall. Dwarf cultivars that grow to 6 inches tall for bedding use are available, and cut flower cultivars up to 3 feet tall are common. Flower types include single, semi-double, double, (dahlia flowered) and cactus (ruffled) flowered. Zinnia is a drought-tolerant, warm-weather annual that does not tolerate frost. This flower is available in a wide variety of colors, and color availability is often seasonally dependent for cut flower sales. Shorter cultivars are also used in annual beds, borders, and containers. This document is ENH 953, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date January 2004. 
 https://edis.ifas.ufl.edu/ep162