Effects Of LED Illumination On Characteristics Of Arabidopsis Thaliana's Growth

With the rapid development of facility agriculture,the agricultural production will completely get rid of the constraints of natural environment,which has a broad prospect.As the fourth generation of new semiconductor light source,LED has a lot of advantages,such as controllable spectrum,long life,high light efficiency,low heat,fast response etc.,which show its broad application prospect in facility agriculture.In this paper,according to the characteristics of the LED light source,we choose the red(?=660nm)and blue light(?=446nm),which are close to the light absorption peak of Chlorophyll a and b and green light(?=660nm)as the light sources,and Arabidopsis thaliana as the research material.Three Arabidopsis thaliana growth experiments were designed to study the changes of the contents of Chlorophyll a,Chlorophyll b,Chlorophyll fluorescence parameters and morphological index etc.of Arabidopsis thaliana grown under different spectrum conditions.Four main results were obtained in this thesis.1.Before the experiment,a set of LED plant chamber 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.In the first Arabidopsis thaliana growth experiment,a series of different ratios of red,green,and blue light as light sources were set for Arabidopsis thaliana,tracking and recording the various changes of Arabidopsis thaliana in the whole lifespan from seeding,photomorphogenesis,flowering and fruit to dying.Finally,according to the collected data for analyzing and processing.It concluded that different lights had different effects on the growth and development of A.thaliana in different stages or at the same stage.This experiment proved that green light has a unique role in regulating the growth and development of A.thaliana that can mediate the effects caused by red or blue light alone.This indicates that green light could either promote or illuminate plant growth and development depending on which light it is mixed with.3.In the second Arabidopsis thaliana growth experiment,the seeds which were selected from the first experiment as the experiment material,the ratios of R:B=4:6 and R:B=2:8 were set separately as the light sources to illuminate the Arabidopsis thaliana,and then tacking and recording the various changes of Arabidopsis thaliana from seeding,photomorphogenesis,flowering and fruit to dying.Finally,according to the collected data for analyzing and processing,it concluded that the light condition of parental Arabidopsis thalian could cause different effects on the growth and development of Arabidopsis thalian's offspring during different stages in the whole lifespan,at the same time,the offspring's light condition has a consanguineous relation to the Arabidopsis thalian's growth and development.4.In the third Arabidopsis thaliana growth experiment,the seeds from the second experiment' CK group were selected as material.The orthogonal experiment which had 3 factors and 3 levels was used in this experiment,and selected the L9(34)as the basis of designing.Then tracking and recording the various changes of Arabidopsis thaliana from seeding,photomorphogenesis,flowering and fruit to dying,and analyzing and processing data by the matrix analysis method and MathCAD software.Finally,the best experiment plan under different requirements as(1)the contents of chlorophyll and carotenoid,(2)chlorophyll fluorescence parameter,(3)morphological index,and(4)the whole lifespan,and found that in the three factors(light quality,light quantity,photoperiod),light quality was the most important factor and had the strongest effects on the Arabidopsis thaliana's growth and development.