A Comparison of Rates of Storage of Sucrose in Eight Clones of Sugar-cane as Measured by Sucrose Uptake in vitro

Storage tissue of a range of sugar-cane clones was assayed for its potential to absorb sugar from a 2 per cent sucrose solution. The storage tissue of high quality commercial clones absorbed more sugar from the external solution than that of low quality Fi and backcross hybrids. The differences in uptake resulted largely from differences in the initial passive uptake of sucrose which was very much greater in the high quality clones. Within clones the passive uptake was consistently greater in the storage tissue from old than from young internodes, the rate being more than doubled in some clones. Differences in the rate of active uptake between clones were smaller and less clear cut, but displayed a similar trend with the high quality clones tending to have higher values. The rate of active uptake was unaffected however by the age of the tissue. It is suggested that the ability of the storage tissue of sugar-cane to accumulate sugar in vitro may be related to the potential sucrose content of clones in the field and that the breeder should further investigate this relationship.