Poster: Oxidative stress

Abs # 66: Hydrogen Peroxide Pretreatment Induced Chilling Protection of Phalaenopsis sp.

Presenter:	Chen, Wei-Ling , butterweilin@yahoo.com.tw
Authors	Chen, Wei-Ling  (A)   Yu, Chih-Wen  (B)   Lin, Chin-Ho  (C)
Affiliations:	(A): Department of Horticulture, National Chung-Hsing University (B): Department of Molecular Biothchnology, Da Yeh University (C): Department of Life Science, National Chung-Hsing University

Phalaenopsis is one of the most important flowers in Taiwan and many species grown commercially are susceptible to chilling injury. Chilling injury that occurs during production and transportation can result in significant losses to the flower industry. In the current study, the effect of hydrogen peroxide (H₂O₂) pretreatment on chilling protection of Phalaenopsis seedlings was studied. Seedlings of Phalaenopsis princelor, a chilling-sensitive cultivar transferred out of flask for 6 months were pretreated with 50 mM of H₂O₂. The percentage of electrolyte leakage from seedlings chilled at 6 degrees Celsius for 3 days declined from 64.8% for the control to 32.3% for seedlings pretreated with H₂O₂. Pretreatment with 50 mM H₂O₂ also increased the time of appearance of chilling injury symptoms for seedlings chilled continuously at 6 degrees Celsius from 48 hours for untreated seedlings to 72 hours for treated seedlings. Seedlings of Phalaenopsis amabilis the same age as Phalaenopsis princelor were also pretreated with 50 mM H₂O₂. The percentage of electrolyte leakage from treated seedlings chilled at 4 degrees Celsius for 4 days declined from 51.9% for controls to 32.9% for treated seedlings. The time to appearance of chilling injury symptoms in Phalaenopsis amabilis seedlings chilled continuously at 4 degrees Celsius increased from 48 hours for untreated seedlings to 96 hours for treated ones. Based on these results, H₂O₂ pretreatment can induce chilling tolerance in Phalaenopsis seedlings and decrease the losses caused by low temperature injury. (This work was supported by a grant from National Science Council, Taiwan, NSC91-2313-B-005-080)