In this study, we determined the phytocomponents using GC-MS and evaluated antioxidant activity by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay of the methanolic extract of six lotus varieties seed in Viet Nam (N. Nucifera). GC-MS chromatogram of the methanolic extract of six lotus varieties seed in Viet Nam showed 27 peaks which indicate the presence of 27 phytochemical constituents. The major phytochemical constituent is methyl-alpha-dgalactopyranoside (66,86-78,69%) in all lotus varieties. Antioxidant activity of liquid extract and condensed extract was found as 8.20-15.67 mg/mL and 0.850-1.286 mg/mL in comparison with IC50 of ascorbic acid (3.2 μg/mL). Moreover, 50 % of the DPPH scavenging ability of liquid and condensed extract differed from each other. From obtained results, the seeds of six lotus varieties in Viet Nam were found to be potential for bioactive compounds and antioxidant activity.

Black pepper is a well-known export commodity in Vietnam, but pepper production has been decreasing in recent years. The lack of knowledge about the origin and genetic characteristics of pepper varieties may create variety degradation and loss of product quality. Therefore, it is necessary to study the genetic diversity of existing local and imported pepper varieties and effectively propagate and create new varieties with high yields and quality. In this study, RAPD markers were used with 100 RAPD UBC primers to study genetic diversity. Twelve RAPD primers were selected to amplify 39 pepper cultivars, and 40 polymorphic DNA bands were created with sizes ranging from 200 to 1400 bp. Five of the 12 primers amplified all 39 cultivars. The genetic diversity of lines/cultivars in the pepper population is relatively high. The phylogenetic tree of the 39 cultivars has two branches showing similarity ranging from 41.8 to 51%. The first branch includes five pepper individuals, and the second consists of 34 individuals. There is a high diversity among the pepper cultivars in the same population.