Search Results
Abstract
Out of the 25 microorganisms commonly occuring in carnation (Dianthus caryophyllus L. ‘Improved White Sim’) vase solutions, 3 greatly reduced carnation vase life when added individually to vase solutions. Some of these microorganisms also reduced the vase life of roses (Rose hybrida ‘Cara Mia’), chrysanthemums (Chrysanthemum × morifloium Ramat. ‘May Shoesmith’) and other cultivars of carnation (‘Improved Red Sim’ and ‘Improved Pink Sim’). The microorganisms that reduced flower vase life were tentatively identified as a yeast, a fluorescent pseudomonad and a nonfluorescent pseudomonad. A 10-fold reduction in the initial inoculum level affected neither the final microbial concentrations nor the vase life of the test flowers. The effects of the different microbes were not correlated with their effects on solution pH.
Abstract
A description for the design and use of a flowing solution culture for the mung bean bioassay is presented. A single module for the system is an assembly of polyvinyl chloride (PVC) pipe, Tygon tubing, and 12 hypodermic syringe barrels to accomodate 60 cuttings of mung bean, Vigna radiata (L.) R. Wilcz, (5 per syringe barrel). Solution is circulated by an electric fluid pump. A comparison of this system with conventional vial culture indicates no difference in mean root numbers and their standard deviation, although a more stable solution pH is maintained in the flowing system. In the vial system, pH drifted by as much as 1.4 units within 12 hours, but only 0.2 units in the flowing system. The system presented is ideal for investigations where a stable rooting environment is required.
Abstract
Senescence of sweet pea (Lathyrus odoratus L.) flowers was associated with a climacteric rise in ethylene (C2H4) production. Pretreatment for 8 min with 4 mM silver thiosulfate (STS) doubled the vase life of the flowers and enhanced opening of buds on the spike. An overnight pulse at 20°C with 4% sucrose also promoted bud opening. A combined STS and sucrose treatment improved flower quality by promoting bud opening of spikes cut with tight florets, and by delaying floret senescence and abscission in both fresh and stored flowers. Aminooxyacetic acid (AOA) was less effective than STS in extending the vase life of sweet peas.
Abstract
Ribosomes were isolated from styles, receptacles, and petals of cut ‘White Sim’ carnation flowers (Dianthus caryophyllus L.) during flower senescence. In all flower parts the percentage of polysomes decreased for a few days after cutting and then increased coincident with the surge of ethylene production in the final stages of floral senescence. Changes in the polysomal population in petals excised from the same flower at progressive stages of its senescence were identical with those obtained from petals excised from different flowers at similar stages of senescence. The polysomal data confirm the occurrence of increased protein synthesis coincident with ethylene production and the senescence of cut carnation flowers.
The effectiveness of fungistatic atmospheres for postharvest control of Botrytis cinerea Pers. infections on cut rose flowers (Rosa hybrids L.) was investigated. Storing cut `Sonia', `Royalty', and `Gold Rush' roses at 2.5C with 10% CO2 for 5 days, followed by 2 days of cold storage in air, reduced the number of B. cinerea lesions that developed on inoculated and noninoculated flower petals by 77% and 82%, respectively, compared to cold storage for 7 days in air. Higher CO2 concentrations and longer CO2 treatment times reduced disease severity further, but resulted in unacceptable leaf discoloration on some cultivars. No deleterious effects of CO2-enriched storage atmospheres on flower quality, weight gain, or vase life were observed. Storage at 2.5C for 7 days in 2 μl SO2/liter reduced B. cinerea infections on inoculated and noninoculated flowers by 53% and 43%, respectively. No deleterious effects on flower quality, weight gain, or vase life were observed. Higher SO2 levels reduced disease severity further, but caused bleaching of the petal margins and necrosis around leaf wounds.
Exposure of dormant corms of Triteleia laxa `Queen Fabiola' to 20 ppm C2H4 for 7 days promoted flowering of small corms and resulted in increased apical meristem size, early sprouting, early flowering, more flowers per Inflorescence, and increased fresh weight of daughter corms and cormels. The respiration rate of the C&treated corms increased to four to five times that of the controls during the 7-day treatment, declined markedly after termination of the C2H4 treatment, but remained higher than that of the controls. The C2H4 effects were associated with increased growth rate and consequently a greater final size of the apical meristem (determined by scanning electron microscopy). Leaves produced by C2H4-treated corms were wider, longer, and weighed more than those of the controls.
Flowering of brodiaea (Triteleia laxa syn. Brodiaea laxa `Queen Fabiola') did not have an obligate requirement for manipulation of temperature or photoperiod. Vernalization of corms reduced the greenhouse forcing phase but did not alter the number of flowers per inflorescence or scape length. Long photoperiods hastened flowering but decreased flower quality and flowering percentage. Scape length, which was not affected by photoperiod or mother corm size, was increased when plants were grown at night temperatures < 10C. Diameter of the apical meristem in the dormant corm, flowering percentage, and flower quality were not affected by a 10-fold increase in corm size above a critical weight (0.6 g). In contrast, the weight and number of daughter corms were closely correlated with mother corm size. The optimum planting depth for brodiaea corms was 10 cm below the soil surface.
Abstract
Treatment of ‘Scania’ standard carnations and ‘Elegance’ spray carnations (Dianthus caryophyllus L.) with silver thiosulate and the biocide Physan before shipment markedly extended shelf life in deionized water after arrival. The treatment extended vase life of ‘Scania’ and ‘Elegance’ 11.5 and 5.2 days, respectively, over controls. Pretreatment of ‘Captain Busch’ gladiolus Gladiolus × hortulanus L. H. Bailey with silver thiosulfate alone or with a 10% sucrose pulse improved the quality of the spikes but did not extend vase life after shipment.
Abstract
Growth, respiration, and ethylene production patterns of ‘Crenshaw’ and ‘Persian’ cultivars of muskmelon (Cucumis melo L.) were similar to patterns previously established for cantaloupe (‘PMR 45’). From 3 weeks after anthesis the carotenoid content of the pulp of all 3 cultivars steadily increased from the low level characteristic of green tissue. Chlorophyll content decreased throughout the development of the fruits, but in the cantaloupe and ‘Crenshaw’ there was a final loss of chlorophyll during ripening.