Abstract:

Incorporating C₃ plants with C₄ photosynthesis traits by genetic engineering are available for improving plant productivity. Although rattans are a special and big group of plants including 13 genera and ca. 600 species in the world and have been studied since the mid-nineteenth century, the knowledge of its photosynthetic pathway is still lacking. Therefore, it is meaningful to determine the photosynthetic pathway of rattans. It was reported that chlorophyll a/b value, ratio of stomata occurrence on upper to lower epidermis, activities of phosphoenolpyruvate carboxylase (PEPC) and pyruvate phosphate dikinase (PPDK), and stable carbon isotope ratio in leaves of C₃ plants were lower than those of C₄ plants, thus this study tested them with seedlings and adult plants of the three rattan species, Daemonorops margaritae (Hance) Becc., Calamus simplicifolius C. F. Wei and C. tetradactylus Hance occurring in South China. The results showed that values of these indices were rather low, falling into the ranges of other C₃ plants, so it was concluded that three rattan species were C₃ plants.

Key words: chlorophyll, stomata, phosphoenolpyruvate carboxylase (PEPC), pyruvate phosphate dikinase (PPDK), stable carbon isotope ratio