Abstract:In order to understand the causes of fruit quality differences in Momordica charantia, the contents of cell wall components and related enzyme activities in thick flesh-type ‘LX1-3’ and thin flesh-type ‘ZK54’ were studied during fruit development. The results showed that diameter (FD), lumen diameter (FLD)，pulp thickness (PT), fresh weight (FFW) and fresh weight (FDW) of fruit in ‘LX1-3’ were all higher than those in ‘ZK54’ at 17 days after flowering (DAF). The contents of cell wall components and related enzyme activities were different among cultivars. the content of water-soluble pectin in ‘LX1-3’ was higher than that of ‘ZK54’, and it was significantly positively correlated with PT, FFW, FDW. The contents of hemicellulose (HCE) and cellulose (CE) in ‘LX1-3’ were higher than those in ‘ZK54’ at 17-23 DAF. The activities of β-Gal and β-Xyl of both cultivars at 3 DAF were higher than those at the other three stages. The variation trend of PG, β-Gal and pectinase activities was consistent with that of ionic pectin and covalent pectin. The activities of β-Gal, β-Xyl and cellulase had (extremely) significantly negatively correlated with 5 growth traits, as well as PG with FD, FLD and PT. Therefore, cell wall components and enzyme activities were closely related to fruit development. β-Xyl and β-Gal played major roles in early fruit development, while HCE and CE had great influence on middle and later fruit developments.