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Assimilates distribution in plants of Panicum maximum "cv" Mombaça

Leaf assimilates are exported to plant organs (sinks) in variable pattern according to several factors such as: plant developmental stage, leaf insertion level, intensity of defoliation. The distribution of single leaf assimilates to different fractions of Mombaçagrass plant was assessed as a function of several factors. The factors considered were: 1 Leaf insertion level (top and bottom leaves); 2 Tiller hierarchy (main and primary tillers), and 3 Plant defoliation (control and defoliated plants). Defoliated plants had their blades removed at the ligule level, with exception of the one exposed to 14 CO2. Significance of treatment effects was only observed for the percentage activity retained in plant aerial part, higher figures being found in the tiller of the exposed leaf, regardless of its hierarchy. The shoot retained more activity than the root system. Bottom leaves tended to favor translocation to new tillers, while the top leaf favored translocation to its own tiller. Considering all plant fractions, the top leaf translocated most to the terminal meristem, regardless of its tiller hierarchy and defoliation condition.

assimilates translocation; 14Carbon; source; tillers


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