Effects Of Neotype Light Conversion Plastic Films On Light Environment Condition And Growth,Fruit Yield And Quality Of Sweet Pepper Under Greenhouse

Light quality plays an important role in plant growth and physiological metabolism,previous studies have shown that some of the other visible light from the natural spectrum can be converted into light qualities which are more effective for plant photosynthesis.Sweet pepper(Capsicum annuum L.) is one of the important protected vegetables in China,and it has high nutritional value.Our previous studies found the appropriate ratio of light qualities for sweet pepper growth,and covering the suitable light conversion film is beneficial to its growth and development.Based on that,this study used red sweet pepper ‘Kaitelin’ and ‘Kaiteli’ as materials,and then,the effects of films added by different light conversion agents on the light environment and the growth and development as well as fruit yield and quality under Chinese solar greenhouse were studied.1.Compared with control without light conversion agent,films added by conversion agents of violet to red(VTR) and green to red light(GTR) could significantly improve the light transmittance of red,but reduce the transmittance of violet light and green light,respectively.The stem diameter,leaf number,fruit yield and main fruit quality of sweet pepper under VTR film were significantly higher than those of the control and GTR film,and the yield could be increased by 8.06% and 8.64% separately.Covering this film could significantly increase flavanone-3-hydroxylase(F3H),dihydroflavonol reductase(DFR),anthocyanin synthase(ANS),sucrose synthase(SS),sucrose phosphate synthase(SPS),neutral inverting enzyme(NI),acidic inverting enzyme(AI)and β-amylase activity in sweet pepper fruit.These indicated that the VTR film was beneficial to the growth and development of sweet pepper,promoting anthocyanin and sugar metabolism,as well as improve fruit quality.2.Compared with VTR film,greenhouse covered by VTB film could obviously improve the transmittance of blue light,and the double light conversion film with violet-green to red-blue light conversion agent(C-RBI) could improve the transmittance of red and blue light,but reduce the transmittance of violet and green light.Among them,covering C-RBI film could significantly improve the leaf structure of sweet pepper,induce stomatal opening and increase plant photosynthetic efficiency,and the net photosynthetic rate was 27.9% and 6.37% higher than that of VTR and VTB film,respectively.The plant height,internode length,leaf transverse diameter,leaf number,average fruit weight,fruit yield and phenolic content were significantly increased under this film.In summary,the C-RBI film could optimize the light environment in Chinese solar greenhouse,improve the leaf structure of plant,enhance the plant photosynthetic efficiency,and then,improve the fruit yield and quality of sweet pepper.This C-RBI film was beneficial to the growth and development of sweet pepper.