Brahmi (Bacopa monnieri) is an important medicinal plant mainly used for the treatment of neurological disorders and depression. Recent investigations revealed that bacoside A is major chemical component shown to be responsible for memory facilitating action of brahmi. The current investigation was carried out to assess the potential for increasing biomass and the concentration of bacoside A in the in vitro regenerated shoots by varying sucrose and pH levels of shoot regeneration medium. The leaf explants were cultured on the Murashige and Skoog (MS) medium supplemented with 2 mg l -1 kinetin (KN) and with varying concentrations of sucrose (0, 1, 2, 3, 4, 5 and 6% at pH 5.8) and pH (4.5, 5.0, 5.5, 6.0 and 6.5 with 2% sucrose) with the objective of verifying the effects of sucrose and pH level on shoot regeneration and to verify the accumulation of bacoside A in the regenerated shoots. The shoot biomass increased (150.50 ± 2.84 shoots per explant, fresh wt 6.31 ± 0.12 g and dry wt 250 ± 5.00 mg) on the medium supplemented with 2% sucrose and pH which was set at 4.5. The results of HPLC analysis indicate that increase in sucrose concentration (0, 1, 2, 3, 4, 5 and 6% at pH 5.8) lead to decrease in the bacoside A content (39.51, 22.43, 13.05, 12.17, 10.73, 9.56 and 8.93 mg g -1 dry wt, respectively) in regenerated shoots. These findings provide evidence that stressful condition of inadequate supply of carbon elevated synthesis of bacoside A in brahmi shoots. However, 2% sucrose is found suitable for biomass accumulation. Therefore, medium supplemented with 2% sucrose and pH set at 4.5 was found suitable for both biomass (6.31 ± 0.12 g fresh wt and 250 ± 5.00 mg dry wt) and bacoside A accumulation (13.09 mg g -1 dry wt).

The major objectives of this study were to investigate an efficient rapid protocol for mass propagation of adventitious shoots of brahmi using semisolid and liquid cultures; and to assess the amount of bacoside A accumulated in the regenerated shoots. Leaf explants were grown in vitro on Murashige and Skoog semisolid medium supplemented with 0.5, 1.0, 1.5, 2.0 and 2.5 mg l -1 6-benzyladenine or kinetin (KN) or thidiazuron (TDZ) for 4 weeks. Adventitious shoots developed from leaf explants on all cytokinin supplemented media. After 4 weeks of incubation, leaf explants were split into two batches and one set was subcultured on semisolid medium and another set in liquid medium containing same concentration of cytokinins where they have come from. Highest rate of shoot regeneration was observed for explants cultured on medium with 2 mg l -1 KN. The fresh and dry weight of shoots was also highest with this treatment. Liquid cultures were found suitable for proliferation of shoots (155.6 shoots per explant) and they also favored highest biomass accumulation (8.60 g fresh and 0.35 g dry biomass). The bacoside A contents were determined in shoots using HPLC. Analysis revealed that, the contents were highest with shoots regenerated on medium supplemented with 2 mg l -1 KN. The amount of bacoside A was highest in the shoots regenerated in liquid medium (11.92 mg g -1 DW) and it was 2.2-fold higher compared to shoots grown on semisolid cultures.

Genetic variation of 36 Sechium edule accessions collected across 12 states in India was assessed using morphological traits and DAMD markers. Eighteen fruit morphological traits (both qualitative and quantitative) were evaluated to confirm the variations in the present collection. Quantitative traits showed major variations with respect to fruit weight (7.85-498.33 g/fruit), fruit length (5.8-15 cm/fruit), fruit diameter (6-28 cm/fruit) and length of the spine (0-5 cm). Qualitative traits were also diverse in fruit colour, shape, spine density, reticulation, flexibility of spine and furrow depth. The first six principle components showed 82.88% variation in the principal component analysis. The principal component analysis revealed that fruit weight, fruit width, fruit diameter, fruit shape, length of spine, spine density and furrow depth had a significant contribution to the total variation. The DNA analysis performed using DAMD primers were used for deducing the diversity at DNA level. The collection produced 102 bands out of which 97 were polymorphic and the percentage polymorphism ranged between 66.66 and 100 per primer. Discrete pattern of clustering was obtained using UPGMA method of complete linkage percent disagreement revealing high diversity among the collected accessions. Thus, the present study indicates that molecular and morphological marker map would improve our knowledge of S.edule and would facilitate efforts to breed improved S. edule cultivars.

The gymnemic acid contents in various organs of Gymnema sylvestre were investigated by High Performance Liquid Chromatography (HPLC) method. The results shows that the content of gymnemic acid in various organs, obviously different, was 54.29, 31.66, 28.82, 27.67, 25.39, 20.56 and 1.31 mg·g -1 DW in shoot tips, flowers, nodes, leaves, internodes, roots and seeds, respectively. The highest gymnemic acid content (54.29 mg·g -1 DW) was found in shoot tip, 1.96 fold higher than that in leaves (27.67 mg·g -1 DW). Maximum quantity of gymnemic acid (35.39 mg·g -1 DW) was observed in the young leaves, which was 1.52 times higher than that in old leaves (23.07 mg·g -1 DW). The content of gymnemic acid in young, middle and old internodes was 26.47, 25.77 and 23.94 mg·g -1 DW, respectively, all lower than that in leaves (27.67 mg·g -1 DW), whereas the content of gymnemic acid in young, middle and old nodes was 27.96, 28.81 and 29.66 mg·g -1 DW, respectively, all higher than that in leaves. The study provides the scientific evidences for the rational development and utilization of Gymnema sylvestre resources, since over exploitation of natural stands has caused depletion of these plants in nature.

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