Effects of Different Treatments on Growth and Rooting Characteristics of Quercus mongolica Layering Breeding

With the branches of Quercus mongolica as panicle materials, different kinds and concentrations of exogenous growth substances, different substrates and different layering patterns were applied to determine and analyze the panicle material growth, biomass and rooting characteristics in order to select the optimal exogenous growth substance species and concentrations, substrate composition and layering methods. It was revealed that both potassium indolebutyrate and ABT₁ significantly promoted the rooting of layered panicle material of Q. mongolica, but there were some differences. The biomass of roots, stems, leaves and single plants treated with 10000 mg/L ABT₁(12^# ) were 4.07 times, 1.57 times, 1.29 times and 1.48 times, respectively that of those treated with 5000 mg/L potassium indolebutyrate(5^#) . The rooting rate, rooting amount and longest root length were 1.9 times, 3.16 times and 1.47 times higher than those treated with 5^#, respectively. Moreover, the partial root rate of those undergoing 12^# treatment was only 38.79 %. It was noted that ABT₁ was more suitable as a rooting accelerator for layered panicle materials of Q. mongolica and the rooting rate, rooting amount and longest root length of layered panicle materials of Quercus mongolica reached 23.84%, 7.05 and 16.71 cm, respectively when treated with 10000 mg/L. The plant height, ground diameter, stem dry weight, leaf dry weight, biomass per plant, rooting rate, longest root length and partial root rate of those undergoing 14^# treatment(the mixture of river sand and garden soil in equal volume ratio as the substrate) were superior to those treated with other substrates. Thus, it was a suitable substrate for Q. mongolica layering. Those in the transverse stricture treatment group rooted, but not in the non-transverse stricture treatment group, indicating that the transverse stricture was very important for the rooting of layered panicle material of Q. mongolica. The plant height, ground diameter, root dry weight, stem dry weight, leaf dry weight, single plant biomass, rooting rate, rooting amount and longest root diameter of those treated with upright layering method (4^# treatment) were higher than those treated with lodging layering method (15^# treatment). Therefore, upright layering is suitable for layering of Q. mongolica.