アナアオサの不稔性変異株の生長と光合成‐温度特性

Abstract

Growth and photosynthesis temperature characteristics of the sterile Ulva pertusa (sterile type) were studied and compared with the wild U. pertusa (wild type) collected from the low water mark at Tana in Yamaguchi Prefecture and at Shimoda in Shizuoka Prefecture. The sterile type and the wild type at the Tana site in summer were cultured at 10, 15, 20, 25, 30, and 35°C. The sterile type grew faster than the wild type from 20 to 30°C. Photosynthesis temperature relationships of both types were measured with two seasons. The photosynthetic rate, measured from 5 to 35°C every 5 using the same fronds, was higher in the sterile type than in the wild type at the Tana site in autumn over 25°C. The relative photosynthetic rate, expressed as values relative to that at 20°C, was also higher in the sterile type than in the wild type both at the Tana site and at the Shimoda site in summer over 25°C, while the respiratory rate from 10 to 35°C was lower in the sterile type than in the wild type at the Shimoda site in summer. These results indicate that the rapid growth of the sterile type from 20 to 30°Cis mainly caused by a high photosynthetic rate and a low respiratory rate.