Ethylene-free Environment Research Articles

Evaluation and improvement of post-harvest performance of cut Viburnum tinus inflorescence

Post-harvest performance of cut viburnum inflorescences was examined in the present study. Harvesting viburnum at three developmental stages resulted in significant differences on flower opening rate (FOR) and flower abscission rate (FAR), but not on vase life. Harvesting at Stage III (>50% open flowers) resulted in highest flower opening percentage, whereas harvesting at Stage I (10–30% open flowers) in significantly lower flower abscission percentage. Pulsing with 20 or 40 mg/l AgNO 3 for 24 h extended vase life by 1.6 and 1.9 days, respectively, compared to the controls. Furthermore, flower abscission was significantly reduced after 20 or 40 mg/l AgNO 3 treatments by 51 and 62%, respectively, compared to the controls. In contrast, vase solutions containing 100 mg/l DICA or 100 and 200 mg/l methanol did not extend vase life of cut viburnum inflorescences, but significantly reduced flower abscission. Vase solutions containing 1 or 2% (w/v) sucrose negatively affected vase life, flower opening and flower abscission of viburnum inflorescence. Post-harvest treatments with 1-MCP at 10 μl/l in an ethylene-free environment resulted in extension of vase life and in significant reduction of FAR and respiration rates compared to the controls. Vase life of 1-MCP treated inflorescences was increased by 4.2 days compared to the controls. FAR of 1-MCP treated inflorescences remained significantly lower from the second to the eighth day of the vase life period.

TRANSFORMATION WITH ROL GENES FROM AGROBACTERIUM RHIZOGENES AS A STRATEGY TO BREED COMPACT ORNAMENTAL PLANTS WITH IMPROVED POSTHARVEST QUALITY

ISHS XXIII International EUCARPIA Symposium, Section Ornamentals, Colourful Breeding and Genetics - Part II TRANSFORMATION WITH ROL GENES FROM AGROBACTERIUM RHIZOGENES AS A STRATEGY TO BREED COMPACT ORNAMENTAL PLANTS WITH IMPROVED POSTHARVEST QUALITY

The influence of exogenous acetaldehyde solution on the vase life of two carnation (Dianthus caryophyllils L.) cultivars in the absence or presence of exogenous ethylene

The effects of acetaldehyde concentration (0, 0.025, 0.05, 0.1, 0.2,0.3, 0.4 or 0.5%) in solution on the vase life and ethylene productionoftwo carnation (Dianthus caryophyllus L.) cultivarscontrasting in vase life (Sandrosa (long lasting) and Yellow Candy (shortlasting)) were studied. In Sandrosa, acetaldehyde solution (0.05%)increased the vase life by 3 days in the absence, or by 2 days in the presence,of exogenous ethylene; the increase in vase life was associated with a delay inthe ethylene climacteric peak. In Yellow Candy, acetaldehyde (0.05%)increased vase life by 3 days, in an ethylene free environment. In the presenceof exogenous ethylene there was no increase in vase life of Yellow Candy.Acetaldehyde failed to inhibit ethylene production in either of the cultivars.It is suggested that acetaldehyde is not involved in the inhibition of ethylenebiosynthesis or sensitivity to ethylene in these two carnation cultivars.

Factors affecting quality and post-production life of Exacum affine

Two cultivars of Exacum affine, White Princess and Royal Dane, were grown under supplementary light conditions (70 and 100 μmol m −2 s −1). The higher light intensity reduced the production time and resulted in increased flower development during the post-production period in an interior environment. To test ethylene responses, the plants were sprayed with the anionic silver thiosulphate complex (STS) and then exposed to 3.5 μl l −1 ethylene or kept in an ethylene-free environment. The post-production quality and life of Exacum plants were reduced by the presence of exogenous ethylene. Inhibition of ethylene action improved post-production flower numbers even in the absence of ethylene.

240 RELATIONSHIP OF GROWING LOCATIONS, HARVEST MATURITY, SUMMER PRUNING, SOIL NITROGEN APPLICATION, AND STORAGE ON FRUIT POSTHARVEST PERFORMANCE IN `HAYWARD' KIWIFRUIT

Fruit from 8 `Hayward' kiwifruit vineyards in central California were harvested at 2 week intervals after soluble solids content (SSC) reached 6% and subjected to 4 and 6 months of storage at 0°C in an ethylene free environment. Fruit characteristics at harvest and postharvest performance varied considerably among locations. Fruit stored for 6 months had the same fresh weight, less flesh firmness and higher SSC, than the 4 months storage. Later harvested fruit had greater fruit flesh firmness and higher SSC after storage. SSC after storage was predictable based on ripe soluble solids content (RSSC) at harvest. Summer pruning reduced while soil nitrogen application increased fruit SSC.

713 PB 391 RELATIONSHIP OF MACRO-MINERAL NUTRITION ON FRUIT POSTHARVEST PERFORMANCE IN `HAYWARD' KIWIFRUIT

Fruit from 8 `Hayward' kiwifruit vineyards in central California were harvested at 2 week intervals after soluble solids content (SSC) reached 6% and subjected to 4 and 6 months of storage at 0°C in an ethylene free environment. Macro-nutrients were analyzed from leaf and fruit tissues. Leaf petiole N and NO3--N were 2 to 3 times higher for vines that had softer fruit after long-term storage. Where the correlations were significant, fruit firmness and SSC were correlated negatively with N, P, K, Cl, and N/Ca and positively with Ca and Mg of leaf and fruit tissues. The significance of the correlations depended on the harvest maturity and growing locations. Soil nitrogen application increased Mg and reduced Ca and Cl in lamina but did not influence macro-nutrients in fruit tissues.

Effect of Ethylene on the Gibberellic Acid-Enhanced Synthesis and Release of Amylase by Isolated Barley Aleurone Layers

Methods were developed and extended to enable the incubation of isolated barley (Hordeum vulgare cv. Himalaya) aleurone layers under carefully controlled conditions for studies on effects of ethylene on amylase synthesis and release. When layers in medium containing gibberellic acid were exposed to ethylene, the synthesis and release of amylase were altered relative to layers maintained in an ethylene-free environment. These ethylene effects were detected at the smallest concentration used, 0.041 nl/ml, indicating a very low threshold value. During the initial 24 h, ethylene accelerated both the appearance of total amylase activity, and the release of this activity from the aleurone layers. On the other hand, ethylene reduced the total amount of amylase activity that was recovered from samples after 48 and 72 h.Ethylene did not stimulate the release of amylase from membrane-bound structures within the aleurone layers, and did not interact with the enzyme directly.The isoelectric patterns of amylase activity and proteins released from control and ethylene-treated aleurone layers in 24 h were identical. Therefore, ethylene promoted only quantitative differences in amylase synthesis rather than qualitative differences.

The effects of ethylene in the root environment upon the development of barley

Following observations that ethylene can occur in anaerobic or partially anaerobic soils at concentrations which can affect plant growth, shoot and root growth of barley plants, maintained in solution culture, were examined after long-term exposure of the roots to ethylene in air; the subsequent growth on transfer to a similar but ethylene-free environment was also studied. Both root and shoot dry weights were reduced slightly by the ethylene treatment; seminal root extension was inhibited greatly while lateral root growth was stimulated; absorption of ions and their transport from root to shoot within the plant was not affected. On transfer to an ethylene free environment the extension rate of the seminal axes increased markedly and was the greater the shorter the period of the preceding ethylene treatment; the extension of laterals initiated during the ethylene treatment was stimulated greatly but the growth of those formed subsequently was inhibited.

Flower-bud blasting in tulips caused by ethylene

Several symptoms are described that characterize the extent of flower-bud blasting in tulips. The disorder could be induced by ethylene applied in concentrations of 0.3 ppm and higher during storage of the bulbs. When ethylene was applied late, the symptoms could be observed in most of the buds immediately after exposure. During subsequent storage in an ethylene-free environment, the injury often increased. When ethylene was applied early, symptoms of blasting appeared only after subsequent treatment for early flowering.