Photosynthesis of daughter-tuber leaves in eddoe population and its contribution to canopy photosynthesis and tuber yield [Japanese]

摘要

Three types of eddoe plants (Colocasia esculenta (L.) Schott), i.e., daughter-tuber type (cv. Uhan and Ishikawawase), mother- and daughter-tuber type (cv. Akame), and mother-tuber type (cv. Taiwan-imo), were cultivated in a drained paddy field. The daughter-tuber leaves of each cultivar were removed to estimate the role of the leaves. The rate of canopy photosynthesis of cv. Uhan was measured in mid-October using a closed chamber system, and then plant was fed with (CO2)-C-13 to estimate the contribution ratio of daughter-tuber leaves to total canopy photosynthesis. The rate of canopy photosynthesis in the plant with and without daughter-tuber leaves was 24.6 and 17.5 mu mol m(-2)s(-1), respectively. The contribution ratio of the photosynthesis of the daughter-tuber leaves to total canopy photosynthesis was 29.1%. Total tuber yield in control plants was 16%, higher and the marketable tuber yield was 34% higher than those in the plants without daughter-tuber leaves. The photosynchate of daughter-tuber leaves greatly contributed to the enlargement of each tuber, and hence tuber weight per plant.