Regulation of 6-benzyl-amino-purine and ethyrel on carbo-assimilates export from leaf and partition in wheat plant

The regulation effects of 6-benzyl-amino-purine (BA, 0.05 g/L) and ethyrel (ETH, 0.5 g/L) on export of carbo-assimilates from wheat leaf and its partition in the whole plant were studied using 14CO2 labelling method. Within 48 hours after labelling, more than 90% of the 14C-assimilates were exported from the labelled leaf. The kinetic equation of 14C remained in labelled leaf treated by BA, ETH and control were y = 0.716e-0.0506t (rt,lny = -0.9623**), y = 0.7319e-0.0471t(rt,lny -0.9676**), y = 0.6912e-0.0567t(rt,lny = -0.9555**), respectively. The duration for 14C to reduce to 50% of the total 14C were 8.1h (BA), 7.1h (CK) and 5.7h (ETH). The exporting equations of 14C from labelled leaf with different treatments were VBA = 0.0363e-0.0506t, VCK = 0.03450e-0.0471t, VETH = 0.0392e-0.0567t. The maximum rate of export were increased by ETH and decreased by BA. It indicated that neither BA nor ETH changed the trends of 14C-assimilate export and BA decreased the rate of 14C-assimilates export from labelled leaf. Therefore 14C-assimilate remained in leaf was higher, while ETH acted quite different. In the total 14C-assimalates of wheat seedling, 50%∼60% partitioned in newborn leaf, 20% was changed into structural compounds, 10% partitioned in roots, 10% was hold by stem and tiller node and little was exported to leaves and sheaths below the labelled leaf. BA retarded 14C-assimilates export from the labelled leaf. Both the 14C-assimilates partitioned in newborn leaf and leaves (including sheaths) below the labelled leaf were decreased. Export of 14C-assimilates to roots were retarded by both BA and ETH