2014 Volume 52 Issue 4 Pages 253-257
The life cycle of a community of variegated Japanese butterbur (Petasites japonicus) found in a field at the Fukuoka University of Education (FUE) campus in April 2012 was investigated. The prevalence and morphology of white sectors in newly regenerated leaves of the same variegated Japanese butterbur plants were greater in April, but less in August and December. The community of normal Japanese butterbur identified in the field at the FUE campus in April 2012 did not exhibit variegation changes during the year. To investigate temperature effects on variegation regeneration, we exhumed variegated Japanese butterbur plants from the field, replanted them in clay pots, removed the aerial portions by mowing, and allowed regrowth in a growth cabinet at 25°C or 18°C for 11 d. The percentage of regenerated leaves exhibiting variegation was 12.8% at 25°C and 28.0% at 18°C. The variegation pattern and morphology in regenerated leaves was diffuse and indistinct at 25°C, whereas the variegation pattern was distinct and robust at 18°C. These results suggest that lower temperatures promote regeneration of variegation patterns in variegated Japanese butterbur leaves. It is possible that regeneration of vivid variegation patterns in variegated Japanese butterbur requires cold temperatures during the winter.
