Differences in monoterpene emission characteristics after ozone exposure between three clones representing major gene pools of Cryptomeria japonica (vol 74, pg 102, 2018)

Tropospheric ozone (O-3) concentration has been increasing. The aim of this study was to compare the effect of O-3 exposure on monoterpene emission rate and the components of Japanese cedar (Cryptomeria japonica) between three major gene pools identified by population genetic structure analysis. At the O-3-FACE (Free-Air O-3 and CO2 Enrichment) facility, 1-year saplings of three clones of Japanese cedar (Donden, Kawazu, and Yakushima) were exposed to ambient double concentrations of O-3. After 15 months of O-3 exposure experiment, monoterpene emission characteristics were evaluated by branch enclosure method using cutting samples of current-year leaves. Basal biogenic volatile organic compound emission rate (E-s) was higher in the O-3 exposure plots, and two-way analysis of variance revealed an effect of the O-3 exposure (p <0.05) and an interaction between the O-3 exposure and clone (p <0.05). Especially, high E-s values were observed in the Yakushima after the O-3 exposure. In addition, the coefficient beta related to temperature sensitivity increased in the O-3 exposure plots (p <0.05). Our findings supported the fact that there are large inter-clone variations in C. japonica. It is important to evaluate the differences in clones considering the genetic diversity and to clarify the mechanism of the differences after long-term moderate O-3 exposure.