Abstract: The activities of Chitinase and β-1,3-glucanase in ‘Ya' pear(Pyrus bretschneideri'Yali') fruit inoculated with Botryosphaeria berengriana f.sp. Piricola and healthy pear fruit during growth and storage were measured. The results showed that the activities of Chitinase and β-1,3-glucanase of the inoculated fruit were significantly higher than that of the healthy one and the activities of the rot section and the edge were higher than of healthy pulp, which suggested that the two enzymes were closely correlated to pear fruit resistance to Botryosphaeria berengriana infection. Two enzymes activities were lower at young stage of pear fruit, whereas chitinase activity was higher from 70 d to 130 d after blossom, and the activity peak of β-1,3-glucanase appeared on 130 d after blossom. Therefore, the two enzymes were closely related to pear fruit against ring rot disease at inflating stage. The activities of two enzymes all declined during storage, and in the same time the pear fruit resistance to ring rot disease reduced rapidly. In conclusion, the two enzymes activities of pear fruit may be correlated with the disease resistance during different periods.

Key words: ‘Ya' pear fruit, Botryosphaeria berengriana, Chitinase, β-1, 3-glucanase, period of growth, period of storage