イタドリの二酸化イオウ(SO_2)に対する高い抵抗性について

概要

論文の詳細を見る
The effects of sulfur dioxide (SO_2) on the photosynthesis for Polygonum cuspidatum propagated from shoots sampled near a copper mine at Asio, Tochigi Pref., were compared with those of Helianthus annuus, known as a sensitive plant to SO_2. The percentage inhibition of net photosynthesis and leaf conductance was plotted against the calculated SO_2 absorption rate. The threshold value of SO_2 absorption to photosynthetic inhibition in P. cuspidatum was larger than that in H. annuus. And the photosynthetic inhibition per unit SO_2 absorption rate in P. cuspidatum was smaller than in H. annuus. Furthermore, we studied the effects of SO_2 on the CO_2 concentration in the substomatal cavity. The CO_2 concentration in P. cuspidatum did not increase, but that in H. annuus did. From these data and the change of the extent of inhibition of photosynthesis and transpiration, the photosynthetic decline in P. cuspidatum exposed to SO_2 was primarily due to stomatal closure of the leaf. It was concluded that photosynthetic activity of P. cuspidatum was tolerant to SO_2 firstly because of the small SO_2 absorption rate by leaves resulting from the small leaf conductance, and secondly because of the high resistance to SO_2 of biochemical processes in the photosynthetic pathway.
日本生態学会の論文
1984-06-30