Application Effect Of "Crop Spring" Amino Acid Fertilizer In Production Of Strawberry Under Plastic Tunnel

For photosynthesis,light is the original driving force of the whole process.Light capture and transfer directly affects the photosynthetic efficiency.Too much light will also lead to the reduction of photochemical efficiency due to photoinhibition.Only when photochemical reaction matches with carbon assimilation reaction,plant photosynthesis can achieve the optimal state."Crop Spring" is a new amino acid fertilizer,in which 5-aminolevulinic acid(ALA)produced by the microorganism fermentation is the main active ingredient.Except ALA,"Crop Spring" also contains a variety of nutrient elements which are necessary for plant growth and development.It is proved to be efficient,non-toxic,non-polluting and environmentally friendly.It is well-documented thatexogenous ALA could not only significantly enhance plant photosynthesis,growth and development and thus promote plant productivity but also dramatically enhance stress resistance of many plant species,suggesting its great application potential in agriculture and forestry.However,theapplication of low concentration of ALA in plant production has seldom been studied.Therefore,in order to provide theoretical basis for ALA application in the production of strawberry,in this study,using the 'red cheek' strawberry as materials,we investigated the effect of different concentrations of "Crop Spring" on leaf fast chlorophyll fluorescence and fruit yield and quality.The main results are as follows:1.During the growing season of strawberry,root application of "Crop Spring" at diluted concentrations of 4000,2000 and 1000 times increased leaf chlorophyll content and improved fruit yield and quality.The test results of the M-PEA-2 multifunctional plant efficiency analyzer showed that "Crop Spring" significantly increased strawberry leaf chlorophyll fluorescence intensity of I-Pphase improved the activity of PSII reaction center,the energy conversion(ABS/CS,TR0/CS,ET0/CS)and the photosynthetic performance index(PIABS,PICS and PItotal).These results indicate that root application of "Crop Spring" fertilizer during the growing season of strawberry can obviously promote strawberry leaf photosynthetic electron transport and energy conversion,and therefore significantly improve leaf photosynthetic efficiency and improve fruit yield and quality.2.To explore the mechanism underlying the regulation of ALA on leaf fast chlorophyll fluorescence,we investigated the effects of electron transport inhibitors on ALA5s effect.Results showed that "Crop Spring" improved the photosynthetic energy conversion activity in both donor side and acceptor side of the PSII reaction center,reduced heat energy dissipation and electron transfer pressure of PSI reaction center.The correlation analysis showed that,"Crop Spring" primarily affected the J-I-P phase of fast chlorophyll fluorescence induction dynamics,suggesting that ALA might regulate the PQ library and far electron transfer.Diuron(DCMU),quinone by thyme(DBMIB)and methyl viologen(MV)blocked the electron transfer from PSII to PSI,but "Crop Spring" fertilizer relieved the inhibitive effects of DCMU,DBMIB and MV,indicating that "Crop Spring" affects the electron transfer near PSI.3.The feasibility of mixed application of "Crop Spring" and "Scala",a major pharmaceutical for the prevention of strawberry gray mold,was investigated by comparative studies on their effects on leaf fast chlorophyll fluorescence and fruit yield and quality.Results showed,compared with the controls,all treatments,including "Crop Spring","Scala",and combination of "Crop Spring" and "Scala",promoted yield of strawberry.And,the effect of combined application of "Crop Spring" and "Scala" was the most obvious.In terms of fruit quality,all treatments improved the contents of soluble sugar,soluble protein and anthocyanin and Vc,and decreased titratable acid content in fruit.No significant difference was found between the fruit quality of the combined treatment and "Crop Spring" alone treatment.Besides,all treatment significantly increased the strawberry leaf photosynthetic performance index,reduced the Vj and M0,demonstrating that all treatments can obviously promote the leaf photosynthetic electron transfer and energy conversion.Likewise,no significant difference was found between the combined treatment and "Crop Spring" alone treatment.These results indicate that "Crop Spring" can be applicated together with "Scala" disinfectantin the production of strawberry.In summary,"Crop Spring" could significantly improve strawberry leaf photosynthetic performance and promote fruit yield and quality.Moreover,the combined application of uCrop Spring" and disinfectant "Scala" did not influence the effect of "Crop Spring".The information of the present study provides theoretical basis for ALA application in the production of strawberry.