Effects of GA₃ and COS involved slow-release fertilizer on seed germination and seed seedling rate of Pinus Yunnanensis

In order to understand the effects of seed soaking in gibberellin(GA₃) and Chitosan oligosaccharide(COS) solution involved slow-release fertilizer(SRF) on seed germination and seed growing seedlings of Pinus yunnanensis, the purpose was to provide the calculation of seed germination and sowing seed amount of Pinus yunnanensis, and to offer scientific basis and reference for substrate fertilization.The L₉(3⁴) orthogonal design was applied to implement the trial of the effects of seed soaking in GA₃ and COS solutions and fertilizing the SRF in the substrate on seed germination traits, Seedling survival rates(SSRs) and seed seedling percents(SSP) of P. yunnanensis. The results showed that mean germination rates(GRs), germination potential(GPs), germination time(MGTs) and germination index(GIs) of treatment combinations(TCs) were 79.0%-88.3%,21.3%-61.0%, 17.1-19.4d and 2.5-2.8 seed/day, respectively, with significant differences of the GPs and MGTs between the TCs(P<0.05 or P<0.01); the dominant factor affecting the GR and GI was the interaction between the COS and fertilized SRF in the substrate, while the SRF was the dominant factor affecting the GP and the MGT. The three fertilization amounts of the SRF in the substrate had significant differences on seed GP and the MGT(P<0.05 or P<0.01). The SSRs SSPs of the TCs were 91.3%-95.8% and 73.3%-82.3%, respectively, with significant differences of the SSRs between the TCs(P< 0.01). The dominant factor affecting the SSR was the SRF, while COS and the interaction of COS and the SRF together constitute the dominant factor with the same effect on the SSP. The combinations of exogenous hormone GA₃, nutrient COS and the SRFs in the substrate significantly changed the seed GPs, MGTs and SSRs(P<0.05 or P<0.01). The TC of the 0.20 g/L GA₃ and 0.5% COS solution soaking seeds combined the 0.50kg/m³ SRF in the substrate had the highest GR and SSP, which could be applied to production practice to ensure the effectively raising seedlings of the seeds, especially improved varieties' seeds.