Patterns of 14C-labelled Assimilate Partitioning in Red and White Clover During Vegetative Growth

Publisher Website
Google Scholar
Abstract
A quantitative analysis of the 14C-labelled assimilate supplied by the expanded leaves on the primary shoot to growing leaves, stem, lateral shoots (branches or stolons) and roots in red and white clover was conducted during vegetative growth. Stem growth of the primary shoot was inhibited in both clovers and utilized no energy resources. The growing leaves at the primary shoot apex of white clover imported 4 per cent of the shoot's assimilate compared with 10 per cent in red clover. At the basal end of the primary shoot, the tap root of white clover imported 16 per cent of the shoot's assimilate compared with 22 per cent in red clover. Branches in red clover and stolons in white clover were by far the largest sinks for primary shoot assimilate, importing 39 per cent and 63 per cent of the labelled assimilate, respectively. Analyses of the translocation of assimilate from individual primary shoot leaves demonstrated that in both clovers older leaves exported more of their assimilate to branches or stolons, whereas younger leaves exported more of their assimilate to roots, and possibly in white clover, to growing leaves at the tip of the shoot. Of the labelled assimilate exported to branches or stolons, each primary shoot leaf exported preferentially to the branch or stolon in its own axil, but in addition exported substantial quantities of assimilate to all other axillary shoots, particularly those arising from basal axils where the subtending leaf had died.