The in vitro cultivation of Panax vietnamensis Ha et et Grushv. in the natural and greenhouse conditions in Lam Dong province

Abstract

Currently, Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.) is being over-exploited, so it is difficult to take the initiative in seed sources. In this study, Ngoc Linh ginseng derived from in vitro culture was used as an initial material source to investigate the effect of different types of substrates (Pindstrup clean soil, mountain humus, coconut fiber, dry cow manure, mushrooms cultivated residues, and rice husks), minerals (N:P₂O₅:K₂O ratio), and ecological conditions of four farming models (two greenhouse models, one roof house model, and one natural model) on adaptability, growth, development, and flowering of Ngoc Linh ginseng. The results showed that the Ngoc Linh ginseng derived from tissue culture exhibited good adaptation and growth on the humus soil:dry cow manure:coconut fiber ratio of 1:1:1 and N:P₂O₅:K₂O ratio of 3:1:1 at nursery stage (1 year old, fertilising once a month with a dose of 5 g/plant); meanwhile, it grew well in the planting period (>2 years old, fertilising once a month with a dose of 20 g/plant) under the humus soil:dry cow manure:Pindstrup ratio of 1:1:1, and N:P₂O₅:K₂O ratio of 4:1:3. Besides, the greenhouse model gave a high survival rate (79.8%) and high flowering rate (18 plants). Ngoc Linh ginseng (5 years old) derived from in vitro culture had the ability to accumulate saponins G-Rg₁ (1.248%) and G-Rb₁ (1.012%) that were similar to the natural Ngoc Linh ginseng, and its M-R₂ (1.417%) saponins accumutation was lower than that of natural Ngoc Linh ginseng (Quang Nam and Kon Tum provinces). This is the basis for being able to migrate Ngoc Linh ginseng to areas with similar ecological conditions to expand the ginseng growing area.