|Iakovoglou, Valasia -|
|Misra, Manjit -|
|Knapp, Allen -|
|Hall, Richard -|
Submitted to: Scandinavian Journal of Forest Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 15, 2014
Publication Date: N/A
Interpretive Summary: Storing and preserving plant seeds is important to the nursery and forestry industries, however, often seeds become inactive during the storage process and fail to germinate. The reasons why these inactive or 'recalcitrant' seeds fail to thrive can be influenced by storage temperature and moisture conditions. Some research has shown that changing the composition of the air in the storage containers can help reduce the number of recalictrant seeds. Work has been done with different levels of oxygen and carbon dioxide, but the influence of the gas nitrous oxide has not been extensively investigated. This study was done to investigate the effect of high concentrations of nitrous oxide on the metabolism of white oak seeds in cold storage. It was observed that nitrous oxide changes the metabolic activity of seeds in storage and that this gas may serve as a substitute for oxygen needed by the cells. These results give some insights on possible storage treatments for germplasm conservation of those recalcitrant seeds, that may be valuable to commercial and government nurseries that produce tree seedlings.
Technical Abstract: Storage of recalcitrant seeds remains an unsolved problem. This study investigated the quantitative gas analysis of nitrous oxide (N2O) and air atmospheres on the recalcitrant seeds of Quercus alba by using gas chromatograph. Ten seeds were placed in each sealed atmospheric system of air and 98/2% N2O/oxygen (O2). Three experiments were conducted to study the N2O effect on seed metabolism in relation to levels of O2 and CO2. For the first experiment, seven flasks were randomly assigned in "non-renewed" closed atmospheric systems for air and 98/2% N2O/ O2 for a total of 37 days. Two more experiments were also conducted for 98/2% of N2O/O2 atmosphere, to determine how rate of gas renewal, based on a two and seven days renewal interval, affects quantitatively the gasses (O2, CO2 and N2O). Six flasks were randomly assigned for each experiment. Cumulative results on non-renewed flasks with 98/2% N2O/O2 treatment showed that as time progressed there was an increase in N2O uptake with rates of uptake indicating variation in the magnitude of the N2O uptake throughout the storage time of 37 days, while the seeds cease to utilize O2 by the 11th day. However, CO2 levels did not decrease, suggesting a shift towards fermentation processes. Finally, the two experiments for the 98/2% N2O/O2 indicated that the O2 levels at the every two day gas renewal were not as reduced as at the every seven days experiment. Overall, the results suggest that N2O was utilized by the recalcitrant seeds of Q. alba.