14CO2 Assimilation and Translocation of 14C‐Photosynthates by Different Parts of Indian Mustard (Brassica juncea L.)

The role of leaves, stem and reproductive parts in 14CO2 fixation and subsequent photosynthate translocation was studied in Indian mustard (Brassica juncea L.) at three growth stages. The data indicated that leaves, stem and pods are important sources of photosynthates for seed filling. At bud emergence stage leaves are the principle site of 14CO2, fixation. The contribution of leaves declines at subsequent stages, where as the contribution of pod walls increased from bud emergence stage to ripening stage. The contribution of the stem remains more or less constant at all three growth stages studied. Although stem can fix 14CO2, at bud emergence and flowering stages it imported 14C‐photosynthates from leaves. However, stem exported photosynthates during subsequent growth stages.