Effect of fruit load and girdling on leaf photosynthesis in Mangifera indica L.

摘要: Leaf nitrogen concentration (Nm), mass-to-area ratio, amount of per unit leaf area (Na), nonstructural carbohydrate (TNCa), maximal rate carboxylation (Vcmax), light-saturated photosynthetic electron transport (Jmax), dark respiration (Rd), net assimilation (Anet), quantum yield photosystem II (UPSII), and intercellular CO2 (Ci) were measured in Mangifera indica L. leaves on three types fruit-bearing branches (non-girdled, NG; girdled with high (HFL) low (LFL) fruit load), experiencing similar light exposure. TNCa, Vcmax/Na, Jmax/Na, Rd/Na, Ci, the initial (a) both HFL NG treatments, but Nm, Na, capacity parameters (Vcmax Jmax) lower than treatment. The strong depressing effect girdling cannot therefore be attributed to a change TNCa. By contrast, Na TNCa higher, respectively, LFL treatment, suggesting that content may become driving force behind acclimation changing source–sink relationships, like ones resulting from presence developing fruits. Vcmax/Na Jmax/Na while not affected by load. It is concluded load affect photosynthesis permanently decreasing increasing, concentration. Fruit load, moreover, have an additional affecting relationship between Vcmax Jmax, Na.