Effects Of Silicone On The Seedling Growth Of Kentucky Bluegrass Under Drought Stress

To solve the problem of limited development of turfgrass caused by drought,developing healthy and environmentally friendly silicon fertilizers and regulating the drought tolerance,which is an effective way for low-cost lawn construction,conservation and sustainable development in arid and semi-arid regions.Kentucky Bluegrass?Poa pratensis cv.“Midnight”?varieties was selected as tested materials.The first experiment is germination experiment soaked in organic silicon.The objective of this study is to investigate the effects of organic silicon on the seed germination and roots growth of Kentucky Bluegrass.This experiment adopted three kinds of water treatments:PEG0%,PEG15%,PEG30%,and six Si amendment treatments:0,1,2,3,4,5mmol·L^-1?TEOS as a silicon source??denoted as CK,Si1,Si2,Si3,Si4,Si5?.The objective of second study is to investigate the effects of different concentrations of organic silicon fertilizer on the morphological structure and physiological characteristics of Kentucky bluegrass,also includes silicon deposition characteristics.The experiment Set 0,1,2,2.5,3,4,5 mmol·L^-11 7 levels of silicon fertilizer Gradient?denoted as CK,Si1,Si2,Si2.5,Si3,Si4 and Si5?.The objective of third study is to investigate the effects of different silicon sources and application methods on the root system,water regulation,and photosynthetic characteristics of Kentucky Bluegrass,catch the comprehensive coordination and adaptation mechanism of silicon application of Kentucky Bluegrass under drought and rewatering conditions.This experiment was consisted of five treatments:1 normal watering;2 spraying Fresh water;3 Potassium silicate by soil;4 Spraying inorganic silicon preparation;5 Spraying silicone preparation?denoted as CK,DCK,SSi,ISi,OSi?,silicon concentrations were 2.5mmol·L^-1.Main results are as follows:1.Organic silicon soaking can delay the germination time of Kentucky bluegrass.Silicon in high concentration may inhibit the germination of Kentucky bluegrass and reduce the seed germination potential and germination index.A certain concentration silicone significantly increased the seedling length,total root length,average root diameter,total root surface area and root number of Kentucky bluegrass,improving the drought resistance of Kentucky bluegrass seedlings.2.Foliar silicone application had a positive effect on seedling growth,total root length,root surface area,and root number of Kentucky bluegrass.The main performance were low concentration promotion and high concentration inhibition.At the same time,the membrane permeability can be reduced,and the electrolyte leakage of the leaf cells can be significantly reduced.The effect is best when the concentration of silicon is 2.5 mmol·L^-1.The content of silicon in shoots suggested that the Kentucky bluegrass could absorb the organic silicon through the leaf surface.When the silicon concentration was 3 mmol·L^-1,the absorption of organic silicon was the most significant.3.Potted under drought conditions,the leaf length,leaf width and root phenotype of Kentucky bluegrass decreased with the deepening of drought stress,and re-increased after re-watering.The addition of organic silicon was effective in the morphological changes of the leaves of Kentucky Bluegrass and the recovery after adversity.The promoting effect of inorganic silicon on the root configuration is more effective,and the application method is dominated by leaf application.Secondly,silicon application could reduce the membrane lipid peroxidation and the relative water content of the leaves decreased caused by continuous drought,and increase the content of chlorophyll,so that the drought-resistance of Kentucky Bluegrass was improved.Among the applications,Spraying organic silicon is the most prominent.4.Under the conditions of drought and re-water,spraying silicon on leaves could increase the soil temperature after rewatering,but it had no significant effect on soil moisture content and soil electrolyte content.The quality of Kentucky bluegrass decreased with the increase of drought stress,and then increased gradually after re-watering.Silicon application can relieve the Kentucky bluegrass yellowing and wilting.5.With the deepening of drought,the fertilizer effects of different forms and application modes were as follows:Spraying silicone preparation>Spraying inorganic silicon preparation>Potassium silicate by soil.