关键词: 叶绿素含量, C₄酶, 叶绿素荧光参数, 种间差异, 叶片, 树枝绿色组织

Abstract: All these 3 species of clove, poplar and larch showed that the contents of Chl.a+b in leaf were significantly higher than those in branch, Chl.a/b had no significant differences in clove and larch(p>0.05), but Chl.a/b in branch of poplar was significantly lower than that in leaf(p<0.05). When expressed as unit of chlorophyll, the activities of PEPC, PEPCK, PPDK, NADP-ME, NADP-MDH in branch of clove were respectively 2.4 times, 4.1 times, 3.2 times, 4.5 times and 1.9 times of those in leaf; in branch of poplar were respectively 2.1 times, 15 times, 6.3 times, 6.3 times and 2.8 times of those in leaf, and the corresponding values for larch were respectively 6.8 times, 6.3 times, 4.3 times, 4 times and 5.5 times. However, the differences in enzymes activities between leaf and branch at fresh weight unit were much smaller comparing with so large differences in chlorophyll unit. Inter-species comparison showed that 5 enzymes in poplar leaf and branch were significantly higher than clove and larch. The fact that C₄ enzymatic activities in branch chlorenchyma were much higher than leaf shows that C₄ enzyme-related biochemical processes may exist in the woody chlorenchyma. Electronic transportation rate and PSⅡ efficiency of branch in clove and larch were greater than leaf and contrary tendency was found in poplar. Correlation analysis between photosynthetic parameters and C₄ enzymes showed that the high C₄ enzymatic activities generally had no influence on the chlorophyll fluorescence indices(p>0.05), indicating the complexity of C₄ enzymes functions on the photosynthesis of branch chlorenchyma and C₃ leaf.

Key words: chlorophyll, C₄ enzyme, chlorophyll fluorescence parameters, inter-species differences, chlorenchyma in leaf and branch