Effects Of Different PH Values On P Hysiology And Secondary Metabolites Of Dendrobium Nobile

Water is the source of life,which is not only essential to human beings,but also the same important to plants.60% to 80% of plant fronds consist of water,which as resolution for plant pHotosynthesis,respiration and transpiration.It is the indispensable material for plant growth and reproduction and is closely linked with the normal growth of plants.Hence,a research into plant growth in its acidic and alkaline changes many not only help explore into the pHysiological changes in plant growth,but also help a research into how their pHysiological changes are used to the benefit of environmental changes with the aim to improve environment by means of plants.Den.nobile a perennial prchidaceous plant,is a landscape plant with a high economic value.The research look into the pHysiological and secondary metabolic changes of Den.nobile in different PH values,in which Den.nobile is soaked in acidic and alkaline solutions separately for forty days.Every eight days,the pHysiological and secondary metabolic changes of Den.nobile are examed.The research results are shown as follows:(1)in PH 2 acidic solution,leaves on Den.nobile are spotted as a result of the burn with new ones more serious than the old ones.While in alkaline solution a bigger rate of fallen leaves arises.(2)in the measurement of pHysiological indexes such as CAT,SOD and POD,the first reaction of enzyme varies in different acidic and alkaline solution,but in the end all enzyme shows strong resistances against acidic and alkaline solutions.(3)in the measurement of osmotic anti-bad blood and soluble protein,both high and low PH values increase its volume of soluble protein and reduce the level of osmotic anti-bad blood acidity,which may be the result of too much H+ or OH-which enter plants and finally turn into harmful ROS.Various systems in plants react to counter the stress.(4)No matter PH values are acidic or alkaline,the level of MDA increases.This may be due to too much ROS accumulated in plants.When ROS exceeds its cleaning-up capability,membrane peroxidation aggravated so that MDA in plants rises.The closer to the two poles of PH,the higher the rate of propylene glycol in the leaves of Den.nobile.(5)From secondary metabolic outcome,acid solutions will increase the level of polypHenol.Neutral solution can increase the accumulation of polysaccharide.Whereas,water solution with a comparatively lower or higher PH values will promote the accumulation of flavone in the leaves of Den.nobile.(6)From pHotosynthetic pigments,weak acidic or alkaline solutions help the generation of pigments.(7)In a nutshell,Den.nobile can be grown in wide areas such as areas with acid rain or those with water of neutral or low acidic or alkaline levels.they grow better in weak acidic and bases.So Den.nobile can be grown to the desirable state according to its medicinal and ornamental needs by adjusting its PH values.