Submitted to: Proceedings Wisconsin Annual Potato Meetings
Publication Type: Proceedings
Publication Acceptance Date: January 24, 2013
Publication Date: February 5, 2013
Citation: Bethke, P.C. 2013. Ethylene update [abstract]. Proceedings Wisconsin Annual Potato Meetings. p. 141. Technical Abstract: The gaseous plant hormone ethylene is required for many aspects of plant growth, development and responses to the environment. Potato tubers produce low amounts of ethylene and are highly sensitive to ethylene in the atmosphere. Several responses of potato tubers to endogenous and exogenous ethylene have been described. Endogenous ethylene promotes the establishment of microtuber dormancy. Exogenous ethylene increases tuber respiration rates, affects tuber dormancy and sprouting, and can increase tuber reducing sugar concentrations. Potato tuber respiration rates have been shown to increase at concentrations as low as 0.15 µl L-1 (150 ppb) for cv. White Rose. Despite the potential for ethylene to adversely affect the stored potato crop, there is little information on the amount of ethylene present in the atmosphere of ventilated potato storage facilities. In the absence of this information, informed decisions cannot be made about the need for ethylene monitoring equipment and storage management based on ethylene concentration. Likewise, there is insufficient information on the sensitivity to ethylene of recently developed potato varieties, especially processing potatoes that are bred for long-term storage and low reducing sugar contents. Decreased ethylene sensitivity could contribute to these goals when ethylene is present in the atmosphere by minimizing the adverse effects of ethylene on tuber reducing sugars and respiration rate. In order to better assess the importance of ethylene in the storage atmosphere, measurements of atmospheric ethylene content were made in research and commercial potato storage bins. In most cases, measurements were made from shortly after bins were filled until they were emptied. These data show that ethylene is present in potato storage bins at very low concentrations, and that these concentrations are sufficient to affect stored tuber respiration rates. Several clones of interest to the chip community were examined and these differed in basal respiration rate and differed in the extent that they increased respiration rate when exposed to low amounts of ethylene. Varieties with more stable rates of respiration and with lower basal rates of respiration are likely to be easier to store, and this is a line of investigation that we currently pursuing.