Abstract:

To understand the effects of hormone types and concentrations and substrate on seed germination of Keteleeria evelyniana, and enrich relevant information of seed germination of this species, L₉(3⁴) orthogonal design was employed to conduct the experiment of hormone types and concentrations and substrate at different levels and treatment combinations (TCs). The results show that in the process of seed germination, the germ and cotyledon do not separate from the seed coat, but the young stem sprouts and the new buds grow and develop into the aboveground organs, so the seedlings cultivated by the seeds of K. evelyniana are vegetative propagation seedlings by sprouting buds. The seeds of K. evelyniana begin to germinate 18 days after sowing and the germination ends after 19 days, so the seeds belong to the category of easily germinated seeds in indoor condition. The germination rates (GRs), germination potentials (GPs), mean germination times (MGTs) and germination indexes (GIs) of the TCs are 18.7%-56.0%, 8.3%-27.0%, 3.3-6.7 d and 7.0-18.1 seed/day, respectively, while those of the control (soaking seeds in clear water and sowing on loam) are 13.3%, 11.0%, 9.0 d and 2.7 seed/day, respectively. Except the GP, the germination parameters of the TCs are significantly higher than those of the control (P<0.01). The substrate is the dominant factor affecting seed germination, the loam is beneficial to seed germination; the GRs of the IBA and IAA solution soaking seeds are significantly higher than that of the GA₃ (P<0.01). The results show that 0.45 g/L IBA or 0.30 g/L IAA can improve the GR and GP of the seeds and shorten the germination time.

Key words: Keteleeria evelyniana, exogenous hormone, substrate, germination, sprouting seedling