The Growth And Physiological Responses Of Lysimachia Nummularia ’Aurea’ To Trampling Stress

Relative to the lawn grass, ornamental use, simple maintenance and trampling resistance of dicotyledons for accessibility of urban ecological green land construction provides a new train of thought. In order to investigate the growth and physiology response mechanism of Lysimachia nummularia ’Aurea’ during the trampled and recovery period, four levels of artificial trampling were set up by using a specific roller with teeth in the field. There are no trampling stress, mild trampling stress, moderate trampling stress and severe trampling stress. The main results are as follows:(1) The deeper trampling stress level, the higher relatively electrical conductivity, also the harder for Lysimachia nummularia ’Aurea’ to recover. Therefore, it can be inferred that the relatively electrical conductivity is a visual and quick mark to react the mechanical damage degree of Lysimachia nummularia ’Aurea’ led by trampling.(2) It can be learned from the trend that H2O2 and MDA contents increased first and then decreased during the trampling period, Lysimachia nummularia ’Aurea’ will produce amount of active oxygen while trampled. However, with the increasing of trampling, the activity of antioxidase enhanced and lasted for a long time after the trampling so as to reduce the oxidative damage.(3) At the initial stage of trampling, the content of soluble sugar increased while that of soluble protein remains the same when the trampling stress deepened. It is obvious that the soluble sugar plays a more important role in reducing the mechanical damage than the soluble protein. That is, the soluble sugar has stronger osmoregulation ability than the soluble protein.(4) Lysimachia nummularia ’Aurea’ will activate the antioxidant enzyme system when trampled, especially for those who under the moderate trampling stress treatment. But the sensitivity of the enzymes vary from the kind of enzymes and followed the order that POD>CAT>SOD.(5) The leaves of Lysimachia nummularia ’Aurea’ suffered a serious mechanical damage under the moderate trampling stress treatment, which led to the contents of chlorophyll decrease a lot. The net photosynthetic rate decreased as well. In addition, the accumulation of time will deepen the degree of damage.(6) The new bud germination number, average bud dimension, the average number of leaves, new leaf area and the biomass of Lysimachia nummularia ’Aurea’ under the moderate and severe trampling stress treatment apparently higher than the other treatments during the recovery period. It can be learned that The heavier degree trampling stress treatment will stimulate the regrowth of Lysimachia nummularia ’Aurea’ and improve its recovery ability.In conclusion, Lysimachia nummularia ’Aurea’ under the moderate trampling stress treatment and severe trampling stress treatment grew a better response both in the physiology and growth aspects in trampling and recovery period. However, it can be inferred from every square metre of Lysimachia nummularia ’Aurea’ could withstand a similar adults trampling stress and continued two days a week, about 132 times a day, for seven weeks, and sod was nearly recovered in five weeks time. The conclusion can provide valuable references for the landscape application of the plant.