桑の光合成および光合成産物の転流・消費に関する研究 : 第1報 桑枝条切除後の残葉の光合成能力について

抄録

When shoots of mulberry tree were pruned at the middle part of stem during a growing season, new leaves unfold from lateral buds on a remained shoot to start the regeneration growth. This paper deals with the photosynthetic rate of new leaves unfolded from lateral buds and old ones remained on a shoot when shoots were pruned at different height of stems. Results are summarized as follows. 1) After pruning, the photosynthetic rate of old leaves once rose compared with ones at the same leaf order of unpruned plant. The rising of photosynthetic rate was most remarkable in leaves remained near the pruned part of shoot. Also, the photosynthetic rate of old leaves rose more rapidly to high level when shoots were pruned at the base. While, the photosynthetic rate once rising after pruning gradually fell down and reached the level of unpruned plants during 30 days. 2) The photosynthetic rate of new leaves was different in accordance with the time of bud sprouting, that is, it was relativeIy low when a shoot was pruned at the base, because the time of bud sprouting was delayed. 3) Total nitrogen contents and areal weight of old leaves of pruned plant were higher than those of unpruned one.