Abstract:

This study aimed to investigate the effects of different growth substrates on seed germination and seedling development of Panax japonicus, identifying optimal substrate formulations to support its nursery cultivation. A single-factor randomized block design was adopted using field soil as control (CK), and six substrate mixtures (by volume) were set up, including Lijiang Shentu substrate (A1), coir dust: herbal residue: field soil= 1:3:5 (A2), coir dust: herbal residue= 5:5 (A3), coir dust: field soil= 5:5 (A4), herbal residue: field soil= 5:5 (A5), and coir dust: herbal residue: field soil= 3:1:5 (A6). Germination rate and seedling growth parameters were systematically evaluated. All substrates significantly enhanced germination rates (P<0.05), which ranked as A2>A6>A3>A5>A1>A4>CK. Substrate A4 exhibited the most pronounced growth promotion, increasing root biomass, rhizome diameter, rhizome length, and seedling fresh weight by 88.17%, 41.26%, 31.36%, and 94.3% respectively versus CK, while reducing seedling mortality by 65.09%. The comprehensive evaluation via membership function ranked treatments as A4(0.810)> A6(0.735)> A1(0.699)> A2(0.607)> A3(0.541)> CK(0.033). Substrate cultivation is recognized as an effective approach for enhancing seed propagation of P. japonicus. Among various substrate formulations, those based on coconut coir demonstrated superior performance compared to those incorporating medicinal herb residues. In particular, the mixture of coconut coir and field soil in a ratio of 5:5 and mixture of coconut coir, herbal residue, and field soil in a ratio of 3:1:5 achieved the best overall evaluation, showing significant synergistic promotion in both aerial and underground growth of seedlings. It can be used as the preferred substrate for P. japonicus seed propagation in production.

Key words: Panax japonicus, seed propagation, seedling substrate, germination rate, growth index, membership function method, comprehensive evaluation