Effects of IBA on the Cuttage Propagation of Young Hard Shoots of Paeonia delavayi Under Different Substrates

Young shoots（buds that sprout at the base of seedlings） and hard shoots（stem segments with sprouts） of perennial healthy and disease-free Paeonia delavayi were used as test materials.The effects of plant growth regulator IBA concentration, substrate type and IBA soaking time on the propagation of P.delavayi tender and hard cuttings were studied by three-factor and three-stage orthogonal experiment, in order to provide reference for the large-scale production of P.delavayi.The results showed that the effect of tender cuttings of P.delavayi was obvious.In the tender shoots test, after soaking in 100.0 mg·L^-1 IBA for 1 hour the cutting effect was the best when the substrate ratio of coconut bran and peat was 4∶6.And the cuttings had second best effect grown in the same substrate after 200.0 mg·L^-1IBA soaking for 0.5 hour.The substrate had a significant effect on the rooting and root points of P.delavayi tender branches.IBA hormone concentration and soaking time only had significant effects on the survival rate of tender wood cuttings and the average number of root points, but had no significant effect on other indicators.The primary and secondary effect analysis results indicated the substrate was the most important factor affecting the rooting and rooting of the twig cuttings, followed by the IBA hormone concentration, and the effect of soaking time was the least.The optimal treatment for the propagation of softwood cuttings was 100 mg·L^-1 IBA soaking for 1 hour and then grownin the coconut bran∶peat 4∶6 matrix.This treatment could get the highest rooting rate and the longest root.