Ambient temperature is an important factor in plant growth and survival, yet relatively little is known about the effects of temprature fluctuation. We compared the effects of both mean temperature (20^o C versus 4^o C) and the effects of temperature range (18^o C/22^o C versus 5^o C/35^o C) on rates of germination, survivorship and growth in two ecotypes of Arabidopsis thaliana. We used Col(g1), a commonly used research strain, and Ts-5, a wild ecotype from Tossa del Mar, Spain.

Results/Conclusions

Both strains grew well under constant cool (4^o C) conditions and ambient (18^o C/22^o C) conditions, however under extreme diurnal variation there was a severe decrement in the the growth and survivorship of Col(g1) but only a slight decrease in the growth and survivorship of the Ts-5. We conclude that there is a genetic component underlying the the abilitiy to tolerate diurnal fluctuation that may be orthagonal to the genetic architecture of response to mean temperature.