GENETIC DIVERSITY AND NETWORK WITHIN DESSERT BANANAS (MUSA ACUMINATA CV. AA AND AAA) INFERRED BY NEWLY DESIGNED MATK MARKER

This study aims to evaluate the genetic diversity and network within ten local cultivars of dessert bananas (Musa acuminata cv. AA and AAA) from Indonesia using newly designed matK marker. Result showed that PCR amplifications were successfully carried out. Total aligned and selected sequences were 729 bp, with nucleotide composition high in AT (67.60%) than GC (32.40%). Sequences variation shows high conservation level, comprising 97.94% monomorphics, 0.82% polymorphics, 0.96% InDels, and 0.27% missing data; with high genetic similarity 99.44%-100%. Haplotype diversity was high (Hd=0.844±0.103), forming six haplotypes but low in nucleotide diversity (n=0.231±0.053). Both haplotype network and phylogenetic tree were separated into two clades, following its genomic subgrouping. Clade I comprised of Inarnibal (AA), Cavendish (AAA) and Gros Michel (AAA). Clade II comprised of Sucrier (AA) and Red (AAA). The genetic diversity within genomic group AAA is higher than AA. Both genomic groups cannot be clearly separated due to continuous genetic variation and mutations. Six point mutations were identified; mostly due to substitution of transversion than transition (Ti/Tv=0.5). The finding of this study suggests that the newly designed matK marker is effective for PCR and sufficient to discriminate at intraspecific level of desert bananas.