携帯用光合成・蒸散測定装置によるオオムギとコムギの個葉の環境反応の測定

The rates of photosynthesis and transpiration were measured in barley and wheat under various environmental conditions, with an open system porometer. The rates of photosynthesis and transpiration in the horizontal leaf and vertical leaf had different diurnal variations. The rate of photosynthesis in the vertical leaf was highest in the morning and in the afternoon, while that in the horizontal leaf was highest before noon. The rates of photosynthesis and transpiration and chlorophyll contents were measured for two species(c.v SARI and Akanmugi) of barley grown in submerged soil conditions. At the end of April, chlorophyll contents had decreased and the maintenance respiration acquired in spite of continuous transpiration. The rapid change of photosynthetically active radiation did not affect the rates of photosynthesis or stomatal conductance of SARI grown in submerged soil. The rates of photosynthesis and transpiration and chlorophyll contents were measured for two species(c.v. Hongmangmai and Haruhikari) of wheat grown under different soil water conditions. Chlorophyll content tended to increase in dry soil conditions. Hongmangmai had a higher chlorophyll content than Haruhikari, even at the beginning of May. Hongmangmai had large photosynthetic rate and small transpiration rates under dry soil conditions. These confirm that Hongmangmai has a prominent drought stress tolerance. The open system porometer and the chlorophyll meter may be very useful for comparing physiological characteristics of the plant's response to environmental factors and clarifying differences between plant species.