The Effect Of Nutrient Heterogeneity On Activity Of Related Enzymes Nitrogen Metabolism Of Zoysia Japonica Clonal Ramets

The distribution of natural resources with heterogeneous characteristics,clonal plants ramets connected by the various sub are generally in different environmental conditions,soil nutrient heterogeneity showed different nutrient availability,patch sizes in the space of mosaic,and which changed with the time.Z.japonica as a perennial stoloniferous clonal plants,in the heterogeneous nutrient conditions,physiological response mechanism has significant difference with non-clonal plants.There are the effects of physiological integration between strains,which has an important impact on the Z.japonica ramets in the growth process and the ecological pattern.Under the condition of nutrient heterogeneity,the study on the physiological characteristics of clonal ramets of Z.japonica is not only unique,but also of great significance to the development of some traditional disciplines,such as ecology,physiology,biology and so on.The research used clonal plant Z.japonica as experimental material,The plants were divided into sub lines connected and cut groups,each group set 5 treatments,namely mother and daughter ramets in low nutrient condition?CK?,mother ramet in low&daughter ramet in middle nutrient condition?LM?,mother ramet in low&daughter ramet in high nutrient condition?LH?,mother ramet in middle&daughter ramet in low nutrient condition?ML?,mother ramet in high&daughter ramet in low nutrient condition?HL?,and each heterogeneous treatment repeated 3 times.Fertilization treatments were set to high?30 mL solution was added to per pot,the solution added 7.085g NH₄NO₃,2.063g NaH₂PO₄ and 2.063g KCL per litre?,medium set the concentration 20%of the high nutrient gradient?30 mL?,and low treatment was the same amount of distilled water.The effects of nutrient heterogeneity on growth and physiological characteristics of Z.japonica were searched through comparing the change of growth and physiological indexes.Activity of nitrogen metabolism related enzymes of above and under-ground zoysiagrass in different nutrient conditions.The main conclusions are as follows:1.In terms of mother ramet connected zoysiagrass,plant height,above and below-ground biomass increased in the middle and high nutrient processing,and which were smaller than those in cut ramets.The plant height,above and below-ground biomass of connected daughter ramets were higher than those in cut ramets.When mother ramets of zoysiagrass were in a relatively high nutrient and daughter ramets in a relatively low nutrient conditions,plants may through some physiological integration,transfer nutrients to the sub strains,and maintained its normal growth.While the daughter ramets in a relatively high nutrition and mother ramets in a relatively low nutrition condition,the plant height,above and below-ground biomass of mother ramets in connected and cut treatment had no change compared with those in control group,which may due to the directionality of the action of physiological integration.2.The root-shoot ratio of connected and cut ramets were decreased in vary degrees in the middle and high nutrient treatment than that in other control.Middle and high nutrient may promote the growth of aerial part.The change of chlorophyll content in connected and cut ramets showed that middle and high nutrient group increased chlorophyll content to a certain extent.Mother ramet transported nutrient to the connected daughter ramet through stolon in the heterogeneous condition of HL group.This resulted the difference of chlorophyll content between mother ramet and daughter ramet was smaller than other treatment.Physiological integration ecsited while mother ramets in middle and high nutrient.3.The activity of NR in zoysiagrass shoot and root had increased significantly in middle nutrient group,which was more obvious compared with the high nutrient group.This indicated that middle concentration of nutrients is the suitable concentration for Z.japonica nitrate reductase synthesis.The variation of NR activities in the shoot of three groups LM,LH,ML were slightly high than those of the roots,which proved that the ML group existed physiological integration between mother and daughter ramets.4.The activity of GS,GOGAT has increased in connected and cut group whether in above-ground or below-ground of the middle and high nutrient treatments.The increase range of high nutrient group was larger.This result indicated that the high nutrient concentration was the appropriate concentration of nutrients required for GS in this study.By comparing difference of activities of GS and GOGAT between connected and cut groups in the heterogeneous conditions,we found that LM and LH increased.The difference of GS activity in roots of connected and cut groups:ML treatment decreases and the other treatments increased in different extent.The decrease extent of above-ground in ML treatment was larger than below-ground.The difference of GOGAT activity in connectes treatment group was increased compared with the cut group.This result indicated that the group of ML group existed physiological integration between mother and daughter ramets in the synthesizing of GS and GOGAT both above-ground and below-ground.This is more obvious in above-ground.The result is similar to those of NR.The change of activity of GOGAT in roots showed no obvious signs that there existed physiological integration,which may be due to the NADH-GOGAT activity induced by NADH in this study is only occupied only 5%of the GOGAT activity in the plants.5.In middle and high nutrient treatment,the activity of GDH increased significantly in both above-ground and below-ground of Z.japonica,and the increase range of high nutrient group was larger.The results showed that the concentration of nutrient in the high nutrient concentration was more suitable for the synthesis of GDH in Z.japonica.Comparing the activity of connected GDH with the cut group in heterogeneous conditions,we found that ML,HL treatments decreased,and the decreased extent of HL group was larger.The difference of GDH between connected and cut roots group increased LH treatment,decreased in ML,HL treatment group,and decreased more in HL treatment,which indicated that the mother ramet transported material through stolon to the connected daughter ramet in the heterogeneous nutrient,and physiological integration existed between mother and daughter ramets.