Determination Of Physiological And Optimization On The Stem Of Populus Alba × P.berolinensis By Agrobacterium Rhizogenes

Poplar?Populus alba×P.berolinensis?is Salicaceae?Salicaceae?,which is general known as the deciduous tree species of Populus?Populus?.Poplar?Populus alba×P.berolinensis?is a new type of tree species selected from the hybridizationof Populus alba?p.alba Linn?and Populus alba?p.alba Linn?.Poplar is one of the excellent tree species which have the low survival rate and rooting of cuttings is difficult.It great significance to improve the ability to adapt to the living environment.In this study,we chose the young branches of Populus alba×P.Sisterliness as plant material,established the determination of physiological stem of Populous alba×P.sisterliness by Bacteriology Thighbones,optimized the concentration of bacteriology rhizomes is OD₆₀₀to be 0.6;the time of infection was 30 min;the best implant was the upper segment of branch;the dosage of cinnamon to the lethal concentration is 30 mg/L.The results of PCR molecular and sequence identification show that mediated transformation system by Bacteriology Tumescence was established.In this paper,the transformed plants of Populous were used as experimental materials,the height of plant,the number of leaves,the area of the leaf,the thickness of stem,and the length of internode and the length,the total surface area,volume,projected area,tip number,branch number,the length of unit square meter soil,the average diameter of root and other morphological indicators;the antioxidant enzymes of malondialdehyde?MDA?,peroxidase?POD?,superoxide dismutase?SOD?;the parameter for the rate of net photosynthetic?Pn?,the of transpiration?Tr?,the guidance of stomatal?Gs?,the concentration of intercellular CO²?Ci?,usage efficiency of water?WUE?;the parameters for the relative electron transport rate of the optical system II?ETR?,the yield of actual photo-chemical quantum?PSII?,photo-chemical quenching?qP?,non photo-chemical quenching?NPQ?and the reaction rate of PS II?Fv/Fm?,the conversion ability of light energy?Fv/Fo?and other parameters were detected and analyzed.Analysis of morphological indexes:the height and interlude of the transformed plants were shorter,the area of leaf was decreased and the rate of growth was higher than that of the control plants;the length of interlude and the length,the total surface area,volume,projected area,tip number,branch number,the length of unit square meter soil,the average diameter for the root of transformed plants were greater than control plants.It shows that the roots of transformed plants are more luxuriant,the number of lateral roots are more than the control plants,what makes transformed plants absorb more water and nutrients to provide plant to growth and development well.Analysis of antioxidant enzyme activity:the activity of MDA in the transformed plants was lower than that of control plants,what indicated that the accumulation of reactive oxygen species was less,and the accumulation of reactive oxygen species can damage the plant membrane system.The activity of SOD and POD in transformed plants were higher than those in control plants,the results showed that the transformed plants had stronger ability to scavenge free radicals and maintained the balance of reactive oxygen species.Analysis of photosynthetic characteristics:the Pn of transformed plants were higher than that of control plants,The trend of Tr,Gs were similar to Pn,it rises and then decreases with the increase of light intensity;The trend of WUE was contrary to Gs,with the increase of light intensity,it decreased and then increased;Ci increased with the increase of light intensity.Under the same light intensity,The Pn,Tr,Gs,WUE and Ci values of transformed plants were higher than those of control plants,that means transformed plants had higher photosynthetic rate and stronger ability to utilize water and light energy.Analysis of chlorophyll fluorescence kinetic:ETR,?PSII,qP,NPQ of transformed plants were higher than those of control plants,the results showed that the capture efficiency and ability to the light utilization of transformed plants were higher,transformed plants can emit excess light energy in the form of heat dissipation.The trend of change of Fv/Fm,Fv/Fo,?PSII,ETR,qP indicate that transformed plants had higher photo chemical efficiency,the adaptability to the change of light intensity,the ability of photosynthetic were stronger.New species of Populous were obtained in this experiment to lay the theoretical foundation for the study of genetic engineering breeding of Poplar.