Studies on the Seed Production of Soybean : I. Effect of temperature on photosynthesis of soybean.

Abstract

The studies were carried out in an attempt to make contribution to the establishment of principles regarding seed production of soybean plants, by elucidating the photosynthetic properties. Measurement of photosynthesis was performed with intact leaves under artificial light. The following results were obtained. Under saturating light condition, photosynthetic activity of soybean leaves increased slowly and reached maximum value at about 60∼120 minutes after insertion in chamber. Apparent photosynthesis and respiration were measured with seedlings at various temperatures ranging from 5 to 40°C. Within the range from 15 to 30°C, temperature little affected the apparent photosynthetic rate, though slight depression was obsered above 26°C up to 30°C. While outside the range from 15 to 30°C, temperature depressed the activity the more severely the more it diverged the range. The optimum temperature of true photosynthesis was found at about 26°C.