Abstract:

To explore the influence mechanism of different bagging treatments on the‘Chili’pear（Pyrus bretschneideri Rehd.‘Chili’）fruit spot and water loss during storage，the appearance and microstructure of polyethylene（PE）-bagged and non-woven fabric-bagged fruit were observed，and the physiological indexes as well as gene expression level were determined. The results showed that the PE-bagged fruit surface was rough and the fruit spot was big，while the non-woven fabric-bagged fruit surface was smooth and the fruit spot was small，and the gene expression level of PbPAL2 in the pericarp of PE-bagged fruit was higher than non-woven fabric-bagged fruit. The weight loss rate of PE-bagged fruit was higher than the control during storage，the pericarp was thinner，with less wax substance，and the surface of pericarp was cracked and cocked. On the contrary，the weight loss rate of non-woven fabric-bagged fruit was lower than PE-bagged fruit during storage，the pericarp was thick，with more wax substance on the surface of pericarp，and the wax crystal was diverse. Preharvest bagging influenced the suberification of fruit spot by regulating the gene expression pattern of PbPAL2，and influenced the water loss during storage by changing the cuticle layer and wax layer structure of pericarp. Preharvest non-woven fabric-bagging treatment was beneficial to improve the fruit appearance quality and delay the water loss of‘Chili’pear during storage.

Key words: pear, bagging, pericarp, microstructure, gene expression, water loss