, 1982 ; Woltering, 1987 ). Ethylene arising from anthropogenic (e.g., auto exhaust fumes) and biological (e.g., ripening fruit) sources can occasionally accumulate to physiologically active concentrations (e.g., 0.1 to 10 μL·L −1 ) inside enclosed areas
Andrew J. Macnish, Ria T. Leonard, and Terril A. Nell
Suparna K. Whale and Zora Singh
ethylene in ripe apples can vary between 25 and 2500 μL·L −1 ( Burg and Burg, 1962 ). Kondo et al. (1991) reported that accumulation of anthocyanin in the fruit skin paralleled the increase in internal ethylene concentration during the growth and
Wei Hu, Ju-Hua Liu, Xiao-Ying Yang, Jian-Bin Zhang, Cai-Hong Jia, Mei-Ying Li, Bi-Yu Xu, and Zhi-Qiang Jin
series of template and primer dilutions were tested to determine the optimal concentrations for maximal target amplification. Amplification efficiencies for the internal control and target genes were between 0.9 and 0.97. Each quantitative real-time PCR
R. Porat, B. Weiss, I. Zipori, and A. Dag
, gas samples were withdrawn from the sealed chambers into gas-tight syringes and injected into gas chromatographs for the determination of respiration and ethylene evolution rates. The carbon dioxide (CO 2 ) concentrations were determined with a gas
Vijaya Kumar Rapaka, James E. Faust, John M. Dole, and Erik S. Runkle
. Ethylene concentration in the headspace of the bags was measured at 24-h intervals during 4 d of storage. At the end of the storage period, cuttings were removed from the bags and evaluated for leaf abscission and shoot apices blackening, and then inserted
Donald J. Huber
replenishment. Evidence for nonselective binding was the observation that 1-MCP partitioned in much higher amounts and at faster rates in the lipid-rich avocado compared with apple fruit ( Dauny et al., 2003 ). The accumulation of internal ethylene during long
Bin Li, Ting Sang, Lizhong He, Jin Sun, Juan Li, and Shirong Guo
Salt stress poses a major environmental threat to agricultural production. At high concentrations of salts in the soil, plants experience a physiological drought because of the inability of roots to extract water, and high concentrations of salts
Robert E. Paull and Nancy Jung Chen
Mesocarp softening during papaya (Carica papaya L.) ripening was impaired by heating at 42C for 30 min followed by 49C for 70 min, with areas of the flesh failing to soften. Disruption of the softening process varied with stage of ripeness and harvest date. The respiratory climacteric and ethylene production were higher and occurred 2 days sooner in the injured fruit than in the noninjured fruit that had been exposed to 49C for only 30 min. Skin degreening and internal carotenoid synthesis were unaffected by the heat treatments. Exposure of ripening fruit to either 42C for 4 hr or 38 to 42C for 1 hr followed by 3 hr at 22C resulted in the development of thermotolerance to exposure to the otherwise injurious heat treatment of 49C for 70 min. Four stainable polypeptide bands increased and seven declined in single-dimensional acrylamide gels following incubation of fruit at the nondamaging temperature of 38C for 2 hr. Three polypeptides showed marked increases when polysomal RNA was translated. These polypeptides had apparent molecular weights of 17, 18, and 70 kDa. Proteins with molecular weights of 46, 54, and 63 kDa had slight increases after heat treatment. The levels of these polypeptides peaked 2 hr after heat treatment and declined within 24 hr. The amount of these polypeptides in the unheated control varied with the batch of fruit. The concentration of three translated polypeptides, with apparent molecular weights of 26, 37, and 46 kDa, declined. Other polypeptides continued to be translated during and after holding papayas for 2 hr at 38C.
Suparna Whale*, Zora Singh, and John Janes
The effects of preharvest application of AVG and ethephon alone, or in combinations, on color development, fruit quality and shelf life were tested in `Pink Lady' apples (Malus domestica Borkh.) in Western Australia during 2002.The experiment aimed at improving color without adversely affecting fruit quality at harvest and after long term cold storage. Treatments included 124.5 g·ha-1 AVG only [148 Days after full bloom (DAFB)]; 280 g·ha-1 ethephon only (148 DAFB); AVG (148 DAFB) followed by ethephon (166 DAFB); and control. Fruit were evaluated for color development, internal ethylene concentration (IEC) and quality at commercial harvest(181DAFB) and 45, 90, and135 days after cold storage (1 °C ± 0.5 °C). At harvest, ethephon with or without AVG significantly (P ≤ 0.05) improved red blush and total anthocyanin in fruit skin. AVG+ethephon treated-fruit had higher total anthocyanin and TSS compared to AVG alone and control fruit. There were no significant differences among different AVG and ethephon treatments for fruit firmness and IEC. During different storage periods, fruit treated with AVG alone and AVG+ethephon had significantly lower IEC compared to fruit treated with ethephon only and the control, however the interactions between treatments and storage periods were not significant for fruit firmness. AVG + ethephon and ethephon alone did not significantly affect fruit color during different storage periods, which showed that the subsequent ethephon spray on AVG-treated fruit had overcome the inhibitory effect of AVG. Our experimental results showed that application of AVG followed by ethephon improved color in `Pink Lady' apples without compromising fruit quality including firmness during extended cold storage.
John M. DeLong, Robert K. Prange, and Peter A. Harrison
`Redcort Cortland' and `Redmax' and `Summerland McIntosh' apples (Malus ×domestica Borkh.) were treated with 900 nL·L-1 of 1-methylcyclopropene (1-MCP) for 24 hours at 20 °C before storage and were kept at 3 °C in either a controlled atmosphere (CA) of 2 kPa O2 and <2.5 kPa CO2 or in an air (RA) environment for up to 9 months. After 4.5 months, half of the fruit were treated with a second 900 nL·L-1 1-MCP application in air at 3 °C for 24 hours and then returned to RA or CA storage. At harvest and following removal at 3, 6, and 9 months and a 7-day shelf life at 20 °C, fruit firmness, titratable acidity (TA) and soluble solids content (SSC) were measured, while internal ethylene concentrations (IEC) in the apple core were quantified after 1 day at 20 °C. Upon storage removal and following a 21-day shelf life at 20 °C, disorder incidence was evaluated. 1-MCP-treated apples, particularly those held in CA-storage, were more firm and had lower IEC than untreated fruit. Higher TA levels were maintained with 1-MCP in all three strains from both storages, while SSC was not affected. Following the 6- and/or 9-month removals, 1-MCP suppressed superficial scald development in all strains and reduced core browning and senescent breakdown in RA-stored `Redmax' and `Summerland' and senescent breakdown in RA-stored `Redcort'. 1-MCP generally maintained the quality of `Cortland' and `McIntosh' fruit held in CA and RA environments (particularly the former) to a higher degree than untreated apples over the 9-month storage period. A second midstorage application of 1-MCP at 3 °C did not improve poststorage fruit quality above a single, prestorage treatment.