Abstract:Chitinase (CHi) is a disease-related protein that can catalyze the hydrolysis of chitin in fungal cell walls and plays an important role in the interaction between plants and fungi. In this study, using the protein sequence of the Arabidopsis chitinase gene as the query sequence, BLASTp alignment was performed in banana A genome (DH-Pahang), and 23 MaCHis gene family members were identified. According to their position on the chromosome, they are named MaCHi01 up to MaCHi23, respectively. Phylogenetic tree analysis showed that the 23 MaCHis can be divided into two subfamilies, GH18 (glycosyl hydrolase 18) and GH19 (glycosyl hydrolase 19). Transcriptome data analysis showed that MaCHi05, MaCHi06, MaCHi07, MaCHi11, MaCHi18, MaCHi19 and MaCHi20 genes were significantly down-regulated or not expressed in the susceptible variety ‘Baxijiao’ after inoculation with Foc TR4, and significantly up-regulated in the disease-resistant variety ‘GCTCV-119’. Using RT-qPCR technology to analyze the expression of MaCHi05, MaCHi06, MaCHi07, MaCHi11 and MaCHi19 in the resistant and susceptible varieties inoculated with Foc TR4, it was found that the expression of these genes was activated in the resistant variety, but not in the susceptible variety, and the relative expression in the resistant variety was much greater than that in the susceptible variety, indicating that these genes participated in the process of banana fusarium wilt resistance in a positively regulated manner. The results of this study provides a theoretical reference for further analysis of the functions of the members of the MaCHi gene family in the process of banana fusarium wilt resistance.