In vitro nodal culture technique of Ehretia asperula Zollinger et Moritzi

Abstract

Ehretia asperula Zollinger et Moritzi has been known as a valuable medicinal plant due to the ability to prevent and treat cancers, and reduce the expansion of tumours, etc. The application of plant tissue culture in preservation and development of Ehretia asperula Zollinger et Moritzi is necessary to enlarge the medicine sources of tropical areas for improving human health. The in vitro node culture techique was applied, and the duration for carying the experiments and recording data was 12 weeks. The nodes from the soil incoculated plantlets were used as explants. The appropriate medium for node culture was the half-strength MS supplemented with BA 0.1 mg/l, which showed the shoot induction rate at 97.20%, number of shoot/node as 1.22, shoot length of 116.67 mm, and number of leaves/shoot as 8.00. The node position affected the micropropagation of the plant. The nodes from the uppermost position to the fourth one had the shoot proliferation insignificantly different to those from the shoot terminal bud. The medium sufficient for rooting of this plant species was the half strength MS supplemented with IBA 0.25 mg/l; as the result, the shoot length was 113.33 mm, the root number was 5.44 roots/shoot, and the root length was 10.33 mm. Investigation of the growth dynamics showed that the in vitro shoot at the week 10 of culture reached 95.00 mm shoot length. By investigating the effect of subculture generation on shoot proliferation, after the 6th subculture, the in vitro plant growth was retarded, with the shoot length of 90.33 mm and leave number of 6.33 leaves/shoot. Acclimatised plantlets grew well and reached 25.6 cm plant heigth after 8 months.