Effects of different substrates,growth regulators,grades of cuttings and metabolism regulator on cutting propagation of Juniperus squamata ‘Blue Star’

Effects of substrates,growth regulators,grades of cuttings and metabolism regulators on the cutting propagation of Juniperus squamata ‘Blue Star’ were researched,and five different grades of cuttings were compared between rooting process and rooting type. Results showed that the rooting rate of the cuttings with the substrate of perlite increased significantly. ABT~1# was superior to other growth regulators on the rooting rate,rooting quality and one-side rooting rate of both softwood and wood cuttings. The optimized combinations were the softwood cuttings treated by perlite+ABT~1# 1 000 mg/L(quickly dipped for 2-3 seconds),and wood cuttings treated by perlite+ABT~1# 500 mg/L (soaked for 1 hour). The rooting rate reached 66.7% and 60.17% separately,and for wood cuttings,the one-side rooting rate was only 28.0%.The rooting ability of cutting grade Ⅰ was the best with 80% rooting rate and better rooting qualities compared with others,the lower rooting ability followed was grade Ⅳ,Ⅱ,Ⅲ,and that of grade Ⅴ was the worst. Metabolism regulators(MS+NaHSO_3) had obvious effects on the rooting ability. The rooting rate of gradeⅤrose by 34.9% compared with the control,when treated by 1/4MS+NaHSO_3(200 mg/L).The same rooting process and different rooting characteristics of five grades of cuttings were found. The adventitious roots of cuttings from grade Ⅰ to Ⅳ mostly originated from cortex of cuttings,but grade Ⅴ from callus tissue of the cuttings' bottom section.