Studies on the growth and the physiology of bryophytes 1. on a method for measuring photosynthesis and respiration of bryophytes with an oxygen electrode system
Shimizu, H.; Shimizu, A.; Furukawa, A.; Totsuka, T.
Miscellanea Bryologica et Lichenologica 9(4): 81-84
As a part of the studies on the physiology and ecology of bryophytes, a method for measuring photosynthetic or respiratory rate of these plants was investigated. An O2 electrode system was used, because the system is an easy way to measure the O2-evolution of uptake rate of plants continuously and is considered to be a suitable method for the accurate measurement of the rate on wet-type bryophytes, e.g., bog mosses. Several modifications in the O2 electrode system were performed, such as the application of the sample holder in the reaction cell and the improvement in the amplification of the electric output from the electrode. These modifications made it possible to measure the evolution or uptake rate of O2 of the bryophytes with a small amount of sample within a short-term period. The net photosynthetic rate (on a chlorophyll basis) of Bryhnia novae-angliae obtained in the present study was almost equal to or rather greater than the rates of other moss species which were previously reported with the chamber method. The tested plant showed a high net photosynthetic rate in the range of 7-36 klx under .apprx. 10-min-illumination.