Analysis of intraspecific genetic variation, antioxidant and antibacterial activities of Zingiber zerumbet

Abstract

Genetic variation of Zingiber zerumbet was determined by a RAPD technique using 7 arbitrary primers, and ITS, trnL intron and trnL-F spacer sequences. The RAPD results showed intraspecific genetic variation (mean He±SD: 0.2297±0.0365 and % polymorphic bands: 62.86%). In addition, results of ITS, trnL intron and trnL-F spacer sequences revealed 856 variable sites, 451 nucleotide transitions and 147 nucleotide transverstions. The intraspecific genetic variation was also detected in moderate level with the value of 1.032. Moreover, a neighbor-joining tree generated from RAPD was divided into two main groups, similar to the result of the gene sequence analysis. Significant differences in biological activities among tested samples of Z. zerumbet in the area were found. The antioxidant activities of the ethanolic extracts were determined by FIC and ABTS assay. It showed significantly different abilities in chelating ferrous ion and antioxidant activities (P-vaule<0.05). Moreover, the ethanolic extracts of the tested samples were significantly different effective against both gram negative and positive bacteria (P-vaule<0.05): Esherichia coli, Bacillus subtilis, Bacillus cereus, Stapphylococcus aureus.