1. Shifts in photosynthetic responses to írradiance and temperature in Viola species
- Creator:
- Mishio, M.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- chlorophyll, Viola keiskei, Viola hondoensis-, specific leaf mass, seasonal course of gas exchange, and dark respiration rate
- Language:
- Multiple languages
- Description:
- The steady-state photosynthetic irradiance and temperature responses of Viola hondoensis and V. keiskei (Violaceae) growing in proximity in their nati ve environment and under three levels of artificial shade of relative irradiance (RI) of 7, 20 and 50 % were investigated. The maximum photosynthetic rates and temperature optima under natural conditions were much higher in V. keiskei than in V. hondoensis, except when in leaves of V. keiskei chlorophyll was degraded due to autumn frosts. When grown under artificial shade, both species had higher temperature optima as RI decreased. Since leaves under the three RI conditions experienced a similar leaf temperature, it was concluded that the shifts in the temperature responses with RI resulted from acclimation to the varying irradiance. The higher temperature optima observed in V. keiskei under natural conditions were probably due to the fact that V. keiskei grew in more shady microhabitats than V. hondoensis.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public