Abstract: To study the impact of bagging on pear fruit quality and the development of stone cell，the
fruits of Pyrus bretschneideri‘Dangshan Suli’were bagged at the 15 days post anthesis and collected at
different fruit stages to observe the distribution of sclereid and examine the content of stone cell，lignin and
intermediate metabolite of lignin and the activities of relative enzymes. The results were as following：The
bagged fruits decreased their stone cell content and lignin content by 31.6% and 13.9%，besides the
quantity and diameter of stone cells decreased by 28.0% and 45.8%. The sclereid content and lignin
content were extremely significant positive correlation. In the entire period of the development of pear
fruit，the PAL，C4H，4CL and CAD activities of bagged fruit were suppressed；Lignin intermediate
metabolite of cinnamic acid，coumaric acid，caffeic acid，ferulic acid content decreased. The bagging
reduced lignin synthesis and the development of sclereid has been hampered. The lignin synthesis of
Dangshan Suli pear fruit may be mainly through coumaric acid pathway.

Key words: Pyrus bretschneideri, bagging, stone cell, lignin metabolism