Abstract: Abstract：It was investigated for the effects of thidiazuron（TDZ）by folia spray treatments with
different concentrations on the development of the fruits and seeds of Lilium Oriental Hybrids‘Sorbonne’
at its primary flowering date. The fruit sizes，fruit and seed setting rates were measured in different
development stages. At the same time，it was detected for cell wall-bound invertase activity of fruits，
chlorophyll content and net photosynthesis rate of leaves. The results showed that exogenous TDZ played
a significant role in promoting the fruit expansion and seed maturity，which had a close correlation with
TDZ concentrations and treating time，especially the treatment with 200 μmol · L-1 TDZ performed most
prominent outcome until 30 days later. Furthermore，exogenous TDZ increased the cell wall-bound
invertase activity，total chlorophyll content and net photosynthesis rate，and consequently improved the
development of the fruit and its seeds of lily cultivar‘Sorbonne’. Compared with control group，it was less
for the difference of the TDZ effect on the fruit development at the early stage（10 days）after spray and
it get more and more in the coming days and performed significant different at 30 days. The spray
treatment with 200 μmol · L-1 TDZ was optimal that could improve the fruit transverse，longitudinal
diameter by 1.75 and 1.23 times respectively；That fruit setting rate and seed rate with embryo were
increased by 75.22% and 65.31% respectively，and that the plump seed number and weight per fruit were
as high as 12.89 and 21.87 times of the control respectively.

Key words: Lilium, TDZ, cell wall-bound invertase, fruit；seed