Translocation of Carbohydrate in Cotton: Movement to the Fruiting Bodies

The translocation of 14C-labelled assimilate was followed from main stem leaves on the cotton plant (Gossypium hirsutum) to bolls on the lower sympodia. From the upper leaves the assimilate descends the stem in well-defined strands in the phloem. Where sympodia originate close to these strands some of the assimilate is distributed to the bolls on those sympodia. There is evidence that the involucre, but not the green boll wall, contributes to boll nutrition by assimilation of external CO2.