Research On Light Response Characteristics Of Dynamic Photosynthetic Of Tomato Leaf

Tomato is a very important vegetable in eggplant and is also one of main crops in vegetable growing industry in our province currently. Make use of facilities cultivation to solve vegetables supply in off-season become one of the important measures ,with consumption levels and increased demand for pollution-free vegetables. But facility culture will inevitably lead to microclimate environment factor(light intensity,temperature, humidity and CO2 concentration) of the growth of plant vegetables happen significant changes,and is even more so for greenhouse tomato production who need more light and temperature. However, most of the research about tomatoes on seed physiology and growth physiological, flowering strong physiological, seedling physiology, grafting physiology, mineral nutrition physiological and so on, which also involves some photosynthetic characteristics test reports of tomatoes, mostly environmental factors on the influence of the steady-state photosynthetic response characteristics,has an important guiding significance for matured and facilities of tomato production.We all know microclimate factor can present continuity or sudden change,then photosynthetic system of plant leaf will follow response which has significantly impact of photosynthesis in plants, whether matured within or facilities.In this paper,we using CIRAS - 2 photosynthetic test system and QE65000 fiber spectrometer tests dynamic response of the various parameters of tomatoes photosynthetic system,with 'Paul tower' tomato of Swiss syngenta as test materials,and analyzes the influence of tomato leaf photosynthesis under dynamic light environment, explores the reasons that limit photosynthesis under dynamic light environment . The main results are as follows:1.Pn increases most,Ci reduces most and Gs increases most when light intensity step increase and light intensity starting is the same which is 200μmol?m-2?s-1, light intensity ending is 1000μmol?m-2?s-1; Pn increases most,Ci reduces most and Gs increases most when light intensity ending is the same which is 1000μmol?m-2?s-1, light intensity starting is 200μmol?m-2?s-1. 2.The early response slope of Pn and CE and Ls is the maximum when light intensity step increase and light intensity starting is the same which is 200μmol?m-2?s-1, light intensity ending is 1000μmol?m-2?s-1or when light intensity ending is the same which is 1000μmol?m-2?s-1, light intensity starting is 200μmol?m-2?s-1.3. When light intensity step increasing, chlorophyll fluorescence measured simultaneously ,the dynamic process of F680 and F735 showed that step-order gradient of light intensity the greater, F680 and F735 larger,the Y(II)'larger, and there will be a certain degree of flutter phenomenon,when in-order difference of 600μmol ? m-2 ? s-1, 800μmol ? m-2 ? s-1.4. Pn reduces least,Ci reduces least and Gs increases most when light intensity anti-step dropping and light intensity starting is the same which is 1000μmol?m-2?s-1, light intensity ending is 800μmol?m-2?s-1and light intensity ending is the same which is 200μmol?m-2?s-1, light intensity starting is 400μmol?m-2?s-1.5. The early response slope of Pn is the maximum and CE and Ls is the minimum when light intensity anti-step drop and light intensity starting is the same which is 1000μmol?m-2?s-1, light intensity ending is 200μmol?m-2?s-1or when light intensity ending is the same which is 200μmol?m-2?s-1, light intensity starting is 1000μmol?m-2?s-1.6. When light intensity anti-step dropping, chlorophyll fluorescence measured simultaneously ,the dynamic process of F680 and F735 showed that step-order gradient of light intensity the greater, F680 and F735 fall more,the Y(II)'fall more,and no chattering phenomenon.7.Under the same light intensity pulse which is 1000μmol?m-2?s-1,the peak of Pn of each treatment is almost the same,but the peak is most obvious,when the initial light intensity is 200μmol?m-2?s-1, lasts for 60 seconds.It show that pulse light intensity and initialight intensity are more difference, the duration of the pulse of light is longer, the more adequate photosynthesis.However, chlorophyll fluorescence measured simultaneously ,the dynamic process of F680 and F735 showed that Y(II)'is the largest when the initial light intensity is 200μmol ? m-2 ? s-1 and light intensity pulse lasts for 10 seconds.8. The peak of Pn is most obvious under the same initial light intensity which is 200μmol?m-2?s-1, pulse light intensity is 1000μmol?m-2?s-1, lasts for 60 seconds. Chlorophyll fluorescence measured simultaneously ,the dynamic process of F680 and F735 showed that Y(II)'is the largest when the pulse light intensity is 1000μmol ? m-2 ? s-1 and light intensity pulse lasts for 10 seconds.9. Pn increases most and the early response slope of Pn is the maximum when stimulating light intensity is 1000μmol?m-2?s-1 under the same time darkness; However,the peak of Pn is smaller,the increment of Pn is more when the more time darkness under the same stimulating light. It show that the longer the dark, the greater impact on photosynthesis.