Abstract
In order to clarify the relationship between photosynthetic rates and morphognetic changes of mulberry, the experiment was carried out using mulberries grown in the field. Apparent photosynthetic rates after summer prunning changed from minus to plus values in 5 days after unfolding, in any one of four varieties, and reached the maximum in about 40 days. Among these varieties, values in largeness was in the order of Kenmochi>Kairyoichinose≥Kairyonezumigaeshi>Kokuso No. 21. Dark respiratory rates were high soon after unfolding, reduced rapidly with the progress of leaf age, and reached constant value in about three weeks. The value in Kenmochi was high, but those in other three varieties were low and almost similar among them. Stomatal distribution was low soon after unfolding and reached the maximum (about 950 stomata/mm2) in about 20 days. The distribution in mature leaves surpassed that in early spring by 150 stomata/mm2. Leaf thickness in four varieties soon after unfolding was about two-fifths of that in mature leaves and became thick with progress of leaf age. It took 18 days after unfolding in Kenmochi, 25 days in Kairyoichinose and 33 days in Kokuso No. 21. The differences in leaf thickenss of mature leaves were within 10μm.
