Abstract:

The aims were to explore the cutting rooting method and rooting mechanism of Magnolia officinalis subsp. biloba (Rehd,et Wils.) Law., and promote rapid cultivation of its superior clones. Based on the results of single-factor test, the authour designed L9(34) orthogonal experiments to optimize rooting formula with semi-wood cuttings; collected the lower parts of cuttings regularly to measuring the nutrients contents and the changes of oxidase activity in the phloem; produced the cuttings paraffin sections to observe the rooting location and process. The best rooting formula of M. officinalis subsp. Biloba was as follows: matrix of peat soil:perlite:sand (1:1:1) processed with KIBA 1000 mg/L for 30 min, the rooting rate was up to 94.4%; compared the cuttings immersed with KIBA with the control, the variation regularity of nutrient contents and the activity of PPO and POD were the same in rooting process, but the peak of test groups arrived 10d earlier than the control, the same as the rooting time; the time of POD and PPO activity maximum value matched the rooting time; there were two types of adventitious root occurring in M. officinalis subsp. biloba: latent root primordium and inducible root primordium. The former exists in the outside of young stem cortex, the latter exists in the outsides of leaves gaps of cortex, and the adventitious roots occurring is mainly dominated by inducible root primordium.