Progeny of 158 F5 × F5 crosses of Antirrhinum majus (snapdragon) selected within and among cut flower postharvest longevity (PHL) categories (long = 12.6-16.8 days, middle = 9.3-12.1 days, and short = 4.8-8.9 days) were evaluated for PHL and quality traits. Results were compared with previous studies involving F2 × F2 progeny, and F3, F4, and F5 inbred lines. Heritability of PHL in F5 × F5 progeny (0.77 ± 0.11) agrees with that of inbred lines (0.79 to 0.81) but is higher than in F2 × F2 progeny (0.41). Therefore, selection for increased PHL should progress more rapidly and predictably through application of inbred lines rather than F2 individuals. Significant differences between F5 × F5 progeny PHL categories confirm PHL is heritable with a significant additive component. Heritabilities of quality traits in A. majus are high, suggesting selection for quality traits should progress without difficulty. Phenotypic and genotypic correlations of PHL with quality traits are not consistently significant across PHL studies in A. majus. Discrepancies between studies suggest most traits may not be correlated to PHL or are subject to strong environmental influence.
Jaime A. Weber, William J. Martin, and Dennis P. Stimart
Omaira Avila-Rostant, Adrian M. Lennon, and Pathmanathan Umaharan
associated with L* but rather with changes in a* and b*, which mirror changes in color rather than intensity. Loss of vase life in anthurium is as a result of loss of spathe glossiness, spathe, and spadix browning and spathe bluing ( Elibox and Umaharan, 2008
Michael Knee, Peg McMahon, and Glenn Carey
An undergraduate class in postharvest physiology observed a number of factors in the senescence of cut roses, which had been studied separately in the literature. They assessed the relative importance of the factors in determining vase life. `Samantha' roses were held at 20C in distilled water or a floral preservative. Ethylene treatment caused petal distortion and premature senescence. Floral preservatives stimulated ethylene production, although vase life was extended relative to flowers in water. Higher sugar contents and respiration were maintained in preservative than in water. Water uptake by roses was almost constant, but stem resistance to water flow increased faster in water than in preservative. In the 2nd week of vase life, transpiration exceeded water uptake, particularly for roses in water. As much of this water was lost through leaves as through the flower. The results suggest that a complex interaction of several factors determines vase life.
Daryl C. Joyce
Abscission of flowers of Geraldton wax (Chamelaucium uncinatum Schau., Myrtaceae) exposed to ethylene was prevented by pulsing with silver thiosulfate. Both a short pulse (15 min, 4.0 mm Ag+) at 25°C and an overnight pulse (0.5 mm Ag+) at 2° were effective treatments. Silver thiosulfate did not improve the vase-life of flowers held in air. Gamma irradiation (60Co source), an insect control measure, resulted in a reduction in vase-life; even at doses as low as 0.05 kGy. Vase-life of Geraldton wax flowers was not affected by prior storage for up to 2 weeks at 0° to 2°. Iprodione pretreatment (1 g·liter−1, 30-sec dip) for Botrytis cinerea Pers. control improved the vase-life of flowers stored for 2 weeks. A preservative solution containing sucrose (1% to 3% w/v) and 8-hydroxyquinoline sulfate (200 mg·liter−1) increased the vase-life of Geraldton wax flowers. Higher sucrose levels (>5% w/v) may cause desiccation of foliage and excessive nectar secretion from floral nectaries. Chemical name used: 3-(3,5-dichlorophenyl)-N-(1-methylethyl)-2,4-dioxo-1-imidazolidinecarboxamide (iprodione).
Kenneth R. Schroeder and Dennis P. Stimart
In an effort to reduce chemical usage to prolong postharvest keeping time of cut flowers, a cross was made between a long-lived (vase life, 10.9 days) inbred line of Antirrhinum majus and a short-lived (vase life, 5.0 days) inbred line. The F1 hybrid was backcrossed to the short-lived parent. Sixty plants of the BC1 generation were carried on through three generations of selfing by single-seed descent. Eight replications each of 60 BC1S3 families, the parents, and the F1 hybrid were grown in the greenhouse, harvested with 40-cm stems when five florets opened, and placed in distilled water for vase life evaluation. Stems were discarded when 50% of the florets on a spike wilted, browned, or dried. Three families proved not significantly different from the long-lived inbred parent. Results indicate that inbred backcross breeding shows potential to increase the postharvest keeping time of short-lived Antirrhinum majus inbred lines.
José J.M. van der Meulen-Muisers and Joop C. van Oeveren
To improve the ability to discriminate between Asiatic hybrid lilies (Lilium L.) with regard to cut flower longevity in breeding trials, sources creating nongenetic variation during the preharvest, harvest, or postharvest phases were identified. The bulb stock origin (grower) and evaluation temperature caused only small nongenetic variation in individual flower longevity. In contrast, the developmental stage of floral buds, when cut, produced significant nongenetic variation in flower longevity. This variation could be reduced by delaying harvest. An evaluation temperature of 17 °C was optimal to discriminate between longevity levels compared to 14 and 20 °C. Flower deformation due to withering of the petals was an improved criterion for the termination of flower longevity and was preferred instead of loss of turgor of the petals. Standard conditions for screening and selecting Asiatic hybrid lilies for individual flower longevity after cutting are proposed.
Kenneth R. Schroeder and Dennis P. Stimart
Evaluation of leaf stomatal numbers and postharvest water loss indicate these are important factors in Antirrhinum majus (snapdragon) cut flower postharvest longevity (PHL). Cut flowers with 9 days longer PHL had 53% fewer leaf stomata. Long PHL is associated with an early reduction in transpiration followed by low steady transpiration. Short-lived genotypes had a linear transpiration pattern over the period of PHL indicating poor stomatal control of water loss. Short-lived genotypes had 22% to 33% reductions in fourth quarter transpiration while long-lived genotypes had 2% to 8% reductions. In addition, short-lived genotypes had higher average fourth quarter cut flower weight losses compared to long-lived genotypes. Further investigation of stomatal numbers and functioning relative to PHL may provide breeders a rapid and nondestructive indirect selection method for PHL.
Robert E. Paull, Nancy Jung Chen, and James Deputy
Physiological changes accompanying anthurium flower (Anthurium andraenum Andre) senescence were monitored. Silver pulse treatment of flower stems was used to modify the senescence process. Florets on the spadix continued to open for 5-10 days after harvest. In both treated and untreated flowers, respiration rate was low until senescence began 8 days after harvest. The rate of increase in respiration of silver treated flowers was half that of the controls. Ethylene production remained low throughout the postharvest life of the flowers. Ten days from harvest spathe color began to change from red to blue with no significant changes in the ratios of the anthocyanins. There was a simultaneous change in tissue pH, from 5.2 to 5.6. Tissue organic acids remained constant during senescence. There was a significant increase in spathe tissue ammonium ion due, apparently, to protein breakdown which probably caused the increase in tissue pH. The concentration of tissue phenolics increased during senescence and could have intensified the color change by copigmentation. Flower senescence apparently was not due to a shortage of carbohydrates, though tissue starch levels did decline by about 25%. The ratio of free sugars in the stem, spathe and spadix remained constant with a slight decline in concentration during postharvest life. Senescence probably was caused by water stress due to stem plugging of undetermined nature. Silver-pulsing of the stem reduced the amount of plugging and therefore reduced the rate of change of all the senescence processes.
Toru Hayashi and Setsuko Todoriki
Aqueous solution (2%) of sucrose, glucose, fructose, or maltose delayed bloom wilting and foliage yellowing of cut chrysanthemums [Dendranthema ×grandiflorum (Ramat.) Kitamura] caused by gamma irradiation at 750 Gy. Solutions of silver thiosulfate, sodium dodecylbenzenesulfonate, polyoxyethylene lauryl ether, potassium sorbate, mannitol, sorbitol, glycerol, 6-benzylamino purine, and gibberellin did not reduce irradiation damage. Holding chrysanthemum cut flowers in a sucrose solution before and during irradiation did not influence the vase life, but holding the cut flowers in a sucrose solution following irradiation prolonged the vase life. The results suggest that sugars reduce radiation-induced physiological deterioration of chrysanthemums.
T. Venkatarayappa, M. J. Tsujita, and D. P. Murr
Cut flowers of rose (Rosa hybrida L. cv. Samantha) exhibited a longer vase life when opened in solutions containing cobaltous ion (Co2+). The extended vase life in response to Co2+ was related to 1) an increased water uptake into the cut flower, 2) an improved water balance during opening, 3) a delay in loss of fresh weight, and 4) a prevention of the occurrence of bent-neck. A concentration of 1.5 mm Co2+ gave maximum beneficial effects without injury to the cut flower, while a 2.0 mm concentration induced some toxic symptoms on leaves.