Effects Of LED Illumination On The Growth Characteristics Of Dendrobium Officinale Kimura Et Migo

LED has a lot of advantages,such as controllable spectrum,long life,high light efficiency,low heat,fast response etc.In this paper,according to the characteristics of the LED light source,we choose the red(X=660nm)and blue light(?=446nm),which are close to the light absorption peak of Chlorophylls a and b and green light(?=525nm)as the light sources.Dendrobium officinale Kimura et Migo was used as the research material.Two sets of experiments on Dendrobium officinaleKimura et Migo were designed on the basis of orthogonal test method.The growth trend of Dendrobium officinale Kimura et Migo in different light environments using the growth index,photosynthetic index and quality index was studied,and the optimum light environment for Dendrobium officinale Kimura et Migo was found.The main work done in this thesis is as follows:1.Before the experiment,a set of LED intelligent plant chambers had been designed and assembled completely in which the light quality,light intensity and photoperiod were controlled separately with better light uniformity to establish a solid foundation for the successful completion of the experiment.2.A three-factor two-level orthogonal experiment was designed by using orthogonal test method.The light qualities were set as R:B=8:2 and R:B=2:8,light intensities were PPFD=80?mol·m-2·s-1 and PPFD=120?mol·-2·s-1,photoperiods were L/D=8/14h and L/D=11/13h.The L4(23)was selected as the basis of designing.The adult Dendrobium officinale Kimura et Migo,which had grown for two years,was selected as the research object.The indexes of Dendrobium officinale Kimura et Migo were observed and measured regularly,and the data were processed by matrix analysis method and the Excel,SPSS,Origin,and MathCAD software.The comprehensive indexes of Dendrobium officinale Kimura et Migo combining growth index,photosynthetic index and quality index were found to be the best in the light environment of R:B=24:96?mol·m2·s-18/16h.3.A three-factor three-level orthogonal test was designed by orthogonal test method.The three levels of light intensity are PPFD=70?mol·m-2·s-1,PPFD=100?mool·m-2·s-1,and PPFD=150?mol·m-2·s-1.The three levels of light quality are R:B=1:9,R:B=3:7,and R:B=5:5,and the three levels photoperiod are L/D=6/18h,L/D=10/14h,and L/D=14/10h,and the L9(34)was selected as the basis of designing.The seedlings of Dendrobium officinale Kimura et Migo,which have been growing for half a year,are selected as research objects.The indexes of Dendrobium officinale Kimura et Migo were observed and measured regularly,and the data were processed by matrix analysis and the software of Excel,SPSS,Origin,and MathCAD.The growth index and photosynthetic index of Dendrobium officinale Kimura et Migo were investigated.To investigate the growth index,photosynthetic index and quality index of Dendrobium officinale Kimura et Migo,we found that the comprehensive indexes of Dendrobium officinale Kimura et Migo were the best under the light environment(R:B=35:35 ?mol·m-2·s-1 10/14 h),and light quality had the most influence on the comprehensive index of Dendrobium officinale Kimura et Migo in this experiment,followed by light intensity and photoperiod.Based on the experiments,we arrived at the following conclusion.The comprehensive index of adult Dendrobium officinale Kimura et Migo is the best under the light environment of(R:B=24:96 ?mol·m-2·s-1 8/16 h)and that of Dendrobium officinale Kimura et Migo at seedling stage is the best under the light environment of(R:B=35:35 ?mol·m-2·s-1 10/14h).The results of this experiment have great significance in shortening the growth cycle of Dendrobium officinale Kimura et Migo and improving the economic benefit of Dendrobium officinale Kimura et Migo.