Effects Of Light Conversion Films On Photosynthetic Characteristics,Fruit Yield And Quality Of Tomato

Light is a key environmental factor affecting plant growth,which can not only provide energy for photosynthesis,but also act as an environmental signal to affect all stages of plant growth and development.In addition to light intensity and photoperiod,light quality has a significant regulatory effect on plant growth and development,morphogenesis and physiological metabolism.Studies have shown that some other visible light qualities in natural spectrum can be converted into more efficient ones for plant photosynthesis by using the light conversion films.At present,research on the light conversion film attracts lots of attention,and it has become an important development direction of functionalization technology foragricultural films.Therefore,in this study,tomato variety of ’Jinpengrongyao’was used as the plant material,and regular film without light conversion agent was used as the control to study the effects of plastic greenhouse films added different light conversion agents on the light environment as well as photosynthetic characteristics,fruit yield and quality of tomato under solar greenhouse.The main results are as follows:1.Compared with the regular film without light conversion agent(CK),covering the light conversion films could effectively improve the ratio of light qualities.Moreover,films added by light conversion agents of green to red light(GTR)and violet to red light(VTR)could significantly reduce the transmittance of green or violet light,but increased the transmittance of red light.The double light conversion film with violet and green to red light,violet to blue light,C-RBI-I)simultaneously reduced the transmittance of violet and green light,but increased the transmittance of red and blue light.The photosynthetic pigment content of tomato leaves was significantly increased under light conversion films compared with CK,and compared with other light conversion films,the C-RBI-I film induced stomatal opening and significantly improved the leaf structure.Furthermore,the plant height,stem diameter,leaf number,root vigor and dry matter accumulation of the tomato under C-RBI-I film were increased significantly.The fruits matured earlier and the fruit quality was significantly improved under this film.Meanwhile,compared with CK,GTR and VTR,the yield was increased by 13.19%,12.02% and 10.29%,respectively.These indicated that covering double light conversion film with C-RBI-I was more conducive to the growth and development of tomato.2.On the basis of the above results,further research was investigated and found that compared with the C-RBI-I film,covering films with No.2 double light conversion agent(violet and green light to red light,purple light to blue and far red light,of which the emission wavelength of the violet to blue light-converting agent is 450 nm,C-RBI-II)and No.3 double light conversion agent(violet and green light to red light,purple light to blue and far red light,of which the emission wavelength of the violet to blue light-converting agent is 470 nm,C-RBI-III)could improve the transmittance of red and far-red light.Compared with C-RBI-I film,covering C-RBI-II and C-RBI-III films could enhance the plant root vigor and Pn,and the fruit yield and quality was also optimized.Among them,covering C-RBI-III film has the most significant effect on increasing yield.In addition,covering C-RBI-III film could significantly increase the activities of key enzymes involved in the sucrose metabolism,including SS,SPS,AI and lycopene synthesis pathway,including PSY,PDS,ZDS,GGPPS,and promoted the accumulation of soluble sugar and lycopene,thereby improved the fruit quality of tomato.