VITRO SUCROSE UPTAKE BY INTERNODAL SLICES OF SUGARCANE GENOTYPES VARYING IN MATURITY AND SUCROSE ACCUMULATION POTENTIAL

摘要

The in vitro sucrose uptake from sucrose containing medium by internodal slices of high sugar content var. CoJ 64 was higher than that of low sugar content var. Co 1148, irrespective of the maturity status of the intemodes. The slices of mature internodes, with high endogenous sucrose, also exhibited greater sucrose uptake from the medium. This uptake seems to involve energy dependent active sucrose uptake that may depend upon the capacity of parenchymatous cells to store sucrose and the apparent free space (AFS) of a variety. The time course studies of in vitro sucrose uptake by slices of immature intemodes of var. CoJ 64 and Co 1148 also revealed that sucrose uptake increased with time and throughout the study period, the uptake by immature intemodal slices from CoJ64 was higher compared to that from Co 1148, indicating a higher rate of sucrose uptake in vitro by the cells of high sugar clone. This was also true for the passive diffusion as well as energy dependent active sucrose uptake and the rate of sucrose uptake. The results of in vitro sucrose uptake and in vivo translocation studies carried out in this laboratory earlier corroborate that high quality clones tend to have higher photoassimilate translocation and thus store higher quantities of sucrose in the storage compartment during their maturation phase.