Tulipa edulis is a perennial herb of the genus Tulipa within the Liliaceae and is commonly distributed in the eastern provinces and regions of China, particularly growing on sunny hills, under sparse forest, or along riverbanks. It is also
Cell-free extracts which incorporated mevalonate-2-14C (MVA) into terpenes were obtained from shoot tissue of Tulipa gesneriana L. cv. Golden Melody. Maximal incorporation occurred at pH 6.5 in 0.1 M KH2 PO4-K2HPO4 buffer with an incubation temperature of 35°C. Total incorporation was linear up to 5 mg protein/assay and it could be enhanced by increasing MVA concentration up to 8 × 10-8 M. After differential centrifugation, all enzymatic activity was located in the 100,000 × g supernatant. In combination Mg++ and Mn++, ATP stimulated incorporation more than CTP, GTP, and UTP. Using ATP as the energy source, Mn++ was highly stimulatory at 1 and 5 × 10-3 M. Mg++ alone or in combination with Mn++ was less effective than Mn++.
The radioactivity from MVA was recovered in 2 fractions: the “neutral” fraction isolated by extraction with benzene, and the “acid hydrolyzable” fraction extracted with benzene after acid hydrolysis of the residual aqueous “neutral” fraction. For subsequent identification of the neutral terpene products, the optimal conditions are either high protein concentration (18 mg/assay) after a 15,000 × g centrifugation and a 4-hr incubation period or high protein concentration without centrifugation and a 1-hr incubation period. The optimal conditions for identification of the acid hydrolyzable products are low protein concentration (5 mg/assay) and 1-hr incubation.
Phosphine (PH3) is a potential alternative fumigant to methyl bromide for insect disinfestation of cut flowers. King protea (Protea cynaroides L.), tulip (Tulipa gesneriana `Apeldoorn'), kangaroo paw (Anigozanthos manglesii Hook.), and geraldton wax (Chamelaucium uncinatum `Purple Pride') were fumigated with PH3 at varying concentrations (100 to 8000 μL·L-1) for 2, 4, or 6 hours. Vase life was evaluated at 20 °C, 65% relative humidity, and constant illumination with a photosynthetically active radiation of 15 μmol·m-2·S-1. No significant change in vase life was observed for kangaroo paws after any of the PH3 fumigations. A 6-hour fumigation at 8000 μL·L-1 significantly reduced vase life in king protea, tulip, and geraldton wax flower. Geraldton wax flower and tulip were relatively sensitive to PH3, as they were damaged by 4000 μL·L-1 for 6 hours and 8000 μL·L-1 for 4 hours, respectively. Phosphine has potential as an insect disinfestation fumigant for king protea, tulip, and kangaroo paw at 4000 (μL·L-1 for 6 hours without affecting vase life or causing damage.
The effect of DICA (50 mg·liter-1), BCDMH (12 mg available chlorine/liter), and HQC (250 mg-liter]) on the longevity of 14 popular cut flower species was assessed. Longevity was significantly extended in: Rosa hybrida L. `Gabrielle' and Scilla campanulata L. Squill. by all germicides; Lilium parkmannii L. `Nepal', Gerbera jamesonii L. `Mercy', and Narcissus tazetta L. `Fortune' by DICA and BCDMH; Gypsophila paniculata L. `R22' by DICA and HQC; and Freesia hybrida Eckl. ex Klatt `White Bergunden' by BCDMH. No effect on longevity was found in Dendranthema grandiflora (Ramat) Kitamura. `Horim', Dianthus caryophyllus L. `Medea', Dianthus barbatus L., Iris hollandica L. `Pearl', and Gerbera jamesonii L. `Double Delight'. Longevity was significantly reduced by DICA in Alstroemeria aurantiaca L. `Mona Lisa' and Tulipa hybrida L. `Apeldoorn'. Analysis of microbial concentrations showed that proliferation was effectively controlled by DICA and BCDMH, but not by HQC. Levels of up to 106 cfu·ml-1 were detected in water, indicating that species not affected by germicides can tolerate these microbial quantities. Fresh weight and solution uptake data indicated that germicides acted primarily by improving solution uptake. Longevity was significantly reduced in R. hybrida `Gabrielle' and D. caryophyllus `Medea' flowers placed in solutions containing high counts of microorganisms (>108 cfu·ml-1) isolated from D. caryophyllus or R. hybrida. Chemical names used: 1-bromo-3-chloro-5,5-dimethylhydantoin (BCDMH); sodium dichloroisocyanuric acid (DICA); 8-hydroxyquinoline citrate (HQC).
It has been demonstrated that flower induction and differentiation in the tulip occurs long before flowering takes place in the spring (1, 2). In the Northern Hemisphere, the initiation of floral primordia begins soon after the bulbs are harvested from the fields in late June or early July and normally, differentiation of the floral parts is completed by late August or early September. By determining the effect of various post-harvest storage temperatures on the development of the floral parts, Luyten et al. (2) showed that the optimal temperature range for flower initiation and development is 17 to 20°C. During the course of these studies, it was observed that the apical meristem passed through seven well-defined phases of development. They were designated by use of the Roman numerals I through VII. Later, Beyer (3) reclassified these stages using alphabetical letters and subscripts selected to correspond to the morphological stages of development e.g. “P1” to indicate the first outer whorl of perianth. Beyer’s “G” stage is comparable to Blaauw’s stage VII (Figure 1). The two designations have been used interchangeably in the literature.
Determination of carbohydrates in different organs of 3 tulip cultivars stored at 4°C showed that sucrose and starch constituted 95% of the bulb carbohydrates with reducing sugars constituting 5%. Dry storage at 4° in the dark for 7 or 14 weeks resulted in an increase in total carbohydrates in all cultivars. Starch content of ‘Edith Eddy’, ‘Bellona’ and ‘Schoon-oord’ was increased 28%, 116%, and 270% respectively following 14 weeks of 4°C storage. Changes in sucrose and reducing sugars varied with cultivar and duration of 4° treatment. On a μg/mg dry weight basis, carbohydrate concentrations were generally higher in the shoot, developing bulblets and basalplate than in the storage scales. Dry matter loss was higher in ‘Edith Eddy’ than in ‘Schoonoord’ and ‘Bellona’. The loss of dry matter during 4° storage was reflected by cumulative losses in each of the organs.
‘Paul Richter’ tulips were forced in controlled environment chambers at 26/22, 22/18, and 18/14°C day/night temperatures using high and reduced light intensity and short and long daylengths. Photoperiod had no influence on growth or flowering. Reduced light intensity with the coolest temperature treatment significantly increased the forcing period. Increased forcing temperatures had the greatest impact on plant growth, resulting in reduced Plant flower length, and forcing period. In a second experiment, ‘Paul Richter’ was forced in controlled environment chambers under 8 combinations of day/night temperatures from 18 to 26° day and from 14 to 22° night. The warmer day or night temperatures decreased the forcing period. Plant height was increased with increasing day temperatures, but decreased with increasing night temperature. Flower length decreased with increasing day or night temperatures. First internode length was increased with increasing day temperature but decreased with increasing night temperature, with the exception of a slight increase at a day temperature of 18°. Last internode length was increased only slightly with increasing night temperature. Flower longevity and total length were decreased slightly by increased forcing temperatures.
Petal opening and senescence of cut Gladiolus, Iris, and Narcissus flowers was significantly inhibited by continuous treatment with 1 mm CHI. Vase life was doubled in individual flowers treated when half-open, and a similar effect was detected after pulsing cut gladiolus spikes with 1 mm CHI for 24 hours. Petal wilting was markedly inhibited in flowers treated with CHI and was confined to the outer 2 to 3 mm of petal margins as opposed to the entire petal in untreated flowers. These effects were not seen, however, in CHI-treated cut tulip flowers, where vase life was significantly reduced. CHI markedly inhibited protein synthesis in Gladiolus `New Rose' florets (a decrease of >60%). Treatment with a potent biocide, DICA, did not increase vase life; therefore, CHI was not prolonging flower longevity by preventing microbial growth in the vase solution. The results indicate that de novo protein synthesis is required for bulb flower development and opening and petal wilting and senescence. Chemical names used: cycloheximide (CHI), sodium dichloroisocyanuric acid (DICA).
Using a standard forcing program for early February flowering, the histogenesis of the tulip apical meristem from the vegetative state to the differentiated, immature flower was observed with the scanning and light microscopes. Root and central bulblet development were observed only with the light microscope. Total scape and root growth were measured from initiation to anthesis. The apex was vegetative on July 21, prefloral on August 1, and reached the reproductive stage “G” on August 15. The first internode was formed by August 7 and the last internode was formed just prior to reaching stage “G”. Cell division was observed in the scape from formation until after planting at 9°C. A second phase occurred in the epidermal cells, nodal regions, and vascular bundles immediately after the plants were placed in the greenhouse. It preceded the rapid rate of cell elongation in the scape. Root initiation had commenced by late July. Root growth and differentiation continued in the basal plate until mid-September, resumed during the cold treatment, and continued after the plants were placed in the green-house. The central bulblet was initiated by early August and continued to develop throughout the forcing program.
Tulip ( Tulipa gesneriana L.) is an ornamental geophyte prized for centuries as a cut flower, potted plant, and garden favorite. Tulip bulbs are grown in fields and sold to specialized producers who “force” the plants into flower after a cold