Screening of composite substrates suitable for tissue-cultured plantlets growth of Asparagus cochinchinensis (Lour.) Merr

Abstract Asparagus cochinchinensis (Lour.) Merr is a medicinal, edible and horticulture plant. Seedling breeding relies on tissue-cultured technology, but the transplant from tissue-cultured seedlings to field cultivation poses a problem in the large-scale production of A. cochinchinensis. Tissue-cultured seedlings of A. cochinchinensis were used as materials, and they were transplanted into the substrates that were mixed with coconut bran, peat, vermiculite, perlite or garden soil. The analysis of the physical and chemical properties of the substrate, combined with the survival rate of seedlings, the aboveground parameters (plant height, stem diameter, fresh weight and dry weight), underground parameters (root fresh weight, root dry weight, root length, root diameter, root surface area and root volume) and physiological indexes (malondialdehyde, soluble protein, soluble sugar, proline, chlorophyll and root vigour), allow us to understand the effects of different combination substrates on the growth and physiology of A. cochinchinensis tissue-cultured seedlings. We concluded that the survival rate of seedlings was negatively correlated with the bulk density and conductivity and was positively correlated with the porosity in the substrate. The membership function was used to comprehensively evaluate the indexes of each combination substrate, and it was concluded that coconut bran:perlite:vermiculite = 33.33%:33.33%:33.33% (bulk density = 0.23 g · cm−3, total porosity = 65.07%, pH = 6.30, conductivity = 0.51 mS · cm−1) scored the highest, the survival rate of seedlings reached 87.10%, the aboveground and underground growth were vigorous and the quality was better than other substrates. This research provides technical support for the efficient cultivation of tissue-cultured seedlings of A. cochinchinensis and reduces the cost of raising seedlings.