| China is one of the main tomato producing and consuming countries in the world.With the continuous development and progress of our society,people have higher requirements for greenhouse tomato cultivation and management technology.The growth model is an important tool to study the mechanism of crop growth and development,and it is also an important theoretical basis for the greenhouse management technology.Therefore,this paper studies the weakness of the source-sink theory,analyzes the spatial and temporal distribution rule of sucrose in the greenhouse tomato transport system,and established a set of methods and techniques for the determination of sucrose content,the characterization of source and sink strength,and the management of greenhouse tomato plant type.It has effectively supplemented source-sink theory and promoted the development of tomato management technology in greenhouse.This experiment was carried out in the solar greenhouse of Jiangsu University from February 2,2017 to July 14,2017.The greenhouse tomato was used as the experimental crop(the variety is fenhong 906).During the test,experiment were divided into four groups,one group was irrigated water as control(T0),and the other three groups was irrigated 1/2 times the normal nutrient solution concentration(T1),normal nutrient solution concentration(T2)and 1.5 times the normal nutrient solution concentration(T3)respectively.In this study,using Hyperspectral technology,a test model of sucrose in the greenhouse tomato was established,and then the sucrose content in the different internodes,petiole and fruit stalk of tomato was obtained by this model.The results are as follows:(1)The sucrose solution with different mass fraction was prepared by analyzing pure sucrose and scanned in a spectrometer.By analyzing the relationship between the content of sucrose and the reflection intensity at all wavelengths,the characteristic wavelength was determined to be 931nm,then the reflection intensity at specific wavelengths was the independent variable,the concentration of sucrose was used as the dependent variable and the determination equation of sucrose content was establishedThe grinding extract of greenhouse tomato stalk,petiole and fruit stalk was scanned in a spectrometer.After processing the data,the reflection intensity under931nm was taken into the determination equation of sucrose content,and the correction coefficient of the content of sucrose in each organ were determined to determine according to the measured values obtained by high performance liquid chromatography.The results show that the correlation coefficient between the content of sucrose in the solution and the reflection intensity under 931nm reaches 0.977,and the R~2 of the sucrose detection equation is 0.95.The model simulation results can meet the requirements of the test completely.(2)This study was conducted in the sunlight greenhouse of Jiangsu University from April 1,2017 to July 4,2017.The variety is pink 906.In this paper,the contents of sucrose in different internodes and petioles and at different times in one day were measured,and the spatial and temporal distribution of sucrose content in the greenhouse tomato was studied.The results showed that the diurnal variation trend of sucrose content in the stem was approximately the same in most treatments,and the sucrose content in the stem was low in the middle for most of the day.In the petiole,the diurnal variation trend of sucrose content in the petiole of T1 and T2 groups was basically the same,that was all up first and then reducing and the difference is only at the time of the highest point.The content difference within the petiole was different.In addition,the daily variation of sucrose content in petiole of T3 group is quite different,and in space,the middle and low ends are high.During the flowering stage,the daily variation trend of sucrose content in petiole was almost the same,and the distribution in petioles was more uniform.In addition,there were certain differences in the distribution and distribution of sucrose in tomato carrying tissues under different growth stages and treatments.(3)In this study,the source strength based on sucrose was first proposed,and sucrose yield simulation model of single leaf assimilates based on sucrose content in the petiole and the leaf area simulation model based on growth degree day(GDD)were established according to the experimental data,and the model of the yield simulation model of the single plant assimilate was established.Finally,three models are tested by using the experimental data which are different from the modeling data.The results showed that the determination coefficient R~2 and the statistical regression standard error RMSE between the simulation results of the single leaf assimilate yield simulation model and the 1:1 line were 0.9 and 0.044 mg/(g·cm~2)respectively.The simulation results of the leaf area simulation model and the R~2 and RMSE between the 1:1 lines were 0.99 and 293.16cm~2 respectively,and the simulation model of the single plant assimilate yield was simulated.The results showed that the R~2 and RMSE between the results and the 1:1 line were 0.9 and 93mg respectively,which showed that the sucrose yield simulation model based on the sucrose content in the petiole had a better simulation effect.(4)This study first proposed a method of characterizing sink strength based on content of sucrose in fruit stalk,and then compared the morphological and fruit stalk parameters of greenhouse tomato under different treatment,analyzed the relationship between the daily change of sucrose content in the fruit stalk with the parameters of the fruit stalk and the diameter of the fruit,and explored the influence of the number of fruit setting days to sucrose content of the fruit stalk and fruit sink strength,and then a method of characterizing sink strength based on content of sucrose in fruit stalk was studied.The results showed that fruit sink strength increased first and then decreased with the change of days after fruit setting.The unloading path of sucrose had a very important influence on the fruit development,and the content of sucrose in the fruit stalk was closely related to the activity of the inner enzyme.(5)In view of the limitations of former the old leaf determination and fruit thinning methods,the old leaf determination method based on the sucrose content in the petiole and the fruit thinning method based on the sucrose content in the fruit stalk were proposed.The mechanism of the leaf senescence and the development of the fruit was quantified,and the technology of plant type management was improved.The results showed that compared with the traditional greenhouse management technology,the growth rate of yield and quality fruit reached 5%and 17.8%respectively,and the yield and quality of greenhouse tomatoes were improved. |
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