Abstract:

It is of great significance to explore the softwood cutting propagation technology of Sambucus williamsii for its development and utilization. Taking 2 to 3-year-old semi-lignified branches of S. williamsii as the cutting materials, the effects of different concentrations and treatment time of 3 growth regulators GGR6, NAA and IBA on softwood cutting of S. williamsii were studied by using three-factor and three-level orthogonal design. The results showed that IBA was the best growth regulator with the average rooting rate of 86.67%, which was significantly different from that of GGR and NAA, but the effect difference of GGR6 and NAA was not significant. As to the treatment time, 0.25 h was the best with the average rooting rate of 85.00%, followed by the 1 h treatment with a rooting rate of 82.22%, there was no significant difference between these two treatments, and the average rooting rate under 0.5 h treatment was the lowest, which was 71.67%. The differences of the number of leaves of new branches, the length of branches and the number of roots were extremely significant under different treatments (P<0.01) and the differences of root length were significant (P<0.05). The rooting rate, the number of new branches and leaves, the length of branches, the length of roots and the number of roots of S. williamsii were comprehensively evaluated by using the membership function method, and the result showed that 100 mg/L IBA treatment for 1 h ranked the third in the comprehensive evaluation, but its rooting rate was significantly higher than that of comprehensive evaluation index and ranked in joint first place. Therefore, 100 mg/L IBA treatment for 1 h is more suitable for popularization and application in production.

Key words: Sambucus willamsii, softwood cutting, growth regulator, rooting rate, the number of roots, root length