Study On The Effect Of Light Quality On The Quality Of Pear Fruit

In this paper,the effect of light quality on pear fruit quality was studied by analyzing the content of stone cells and lignin in Pear Fruit under different colord fruit bags made of different color filters and the content of lignin in callus under different LED light,and the gene family of-4-hydroxylase(C4H)of cinnamic acid was analyzed,in order to choose a better fruit bag for pear production to improve pear quality.The 'Dangshansuli' pear fruits were treated with different colored fruit bags(eg.green,purple,red,orange and blue),which were made of different color filters.In order to prevent the weathering effect,a layer of transparent fruit bag was added to the outer layer of the fruit bag,and the transparent fruit bag was treated as a control bag.The content of stone cells,lignin and mineral elements in the growth and development of pear fruit,as well as the content of sugar,acid and soluble solids in the ripening period of the fruit were tested.The callus was induced and subcultured in the young fruit of the pear,and irradiated by light with different wavelengths.The content of lignin and the expression of C4H,a key enzyme in the synthesis process of lignin,was studied in the callus under different light,.controlled by the white fluorescent.At the same time,combined with the bioinformatics analysis of Rosaceae species,the relative expression levels of genes that affect the synthesis of the key enzyme C4H in the process of lignin synthesis during fruit development were studied.Through further experimental verification,the key genes were cloned and the subcellular location was verified.The location results were consistent with predictions.The main results of the experiment are as follows:1.The material and structure of the different color filter films are the same,but the differences of the micro environment in them are very significant.All the bags can pass through the longer wavelengths better,while the short wavelength light transmittance is little,but the red and orange filter films have higher transmittance of red and orange light than the other color filter films,the purple filter films have a higher transmittance of blue light.The light intensity,temperature and relative humidity in all fruit bags are basically the same,but the transparency and moisture retention of the orange fruit bag are the best,the blue fruit bag has the worst light transmittance,the green fruit bag has the best insulation performance and the purple fruit bag has the worst moisture retention.2.The 'Dangshansuli' pear fruits were treated with different colored fruit bags,The fruits treated with green bags had the minimum stone cell and lignin content,and obtained the highest ratio of fresh weight to dry weight.In addition,the soluble solids were decreased compared with the control,respectively,and the content of K and Zn increased significantly;For the fruits treated with purple bags,the soluble solids content has improved compared with the control,which is the highest of all the treatments,but the fruit shape index has decreased,which is the smallest of all the treatments.In addition,the ratio of fresh weight to dry weight increased compared with the control,but the stone cell content,lignin content,total acid content and fruit hardness reduced.Meanwhile,the content of Fe,Ca,K and Zn significantly increased compared with control;The weight and soluble sugar content of the fruits treated with red bag reduced compared with the control,whereas the content of Fe and Zn increased significantly;The soluble sugar content and the hardness of fruits treated with orange bags decreased compared with control,respectively,which were the lowest of all the treatments.The content of stone cell and lignin increased,and the contents of B,Ca and Zn also increased significantly compared with the control;The weight and soluble solids content of the fruits treated with blue bags decreased compared with control,both of which were the minimum of all the treatments,and the fruit hardness of the fruit was the largest,the content of Ca increased,which was found significantly higher than that of control.Comprehensively,the purple bags can reduce the content of stone cell,and increase the soluble sugar content of pear fruits,furthermore,the contents of mineral elements and the fruit hardness is much lower than other treatments,the single fruit weight and fruit shape index are more ideal,thus the purple bags can be used to improve the pear fruit quality.3.The rate of callus induction under different environmental conditions and plant materials was different.The callus induced ratio in culture medium with different hormones were observed in this experiment.At the same time,the callus were cultured in LED culture box with different light quality,the changes of lignin content in the callus were observed.When use the fruit 20 days after full blossom and the culture medium mixed with MS 4.74g,sucrose 30g,agar 8g,2,4-D 2.5ml,6-BA 1ml in the distilled water of 1L,the induction rate of callus was the highest,reaching 99.2%.Except of UV-A light,The lignin content in callus under different light quality cultured increased while the wavelength of light is longer.4.Through the bioinformatics analysis of Rosaceae species,the family members of C4H family in pear,apple,strawberry,plum,black raspberry and peach were 3,2,2,1,2,2 respectively.And we study the relative expression levels of the three homologous genes in'Dangshan Suli',which named PbrC4Hl,PbrC4H2,and PbrC4H3,respectively.5.The full-length CDS of PbrC4Hl gene was successfully cloned and obtained.By constructing the PbrC4H1-GFP transient expression vector,the gene was transformed into the tobacco epidermal cell of leaves and Arabidopsis protoplasts.Through the observation by microscopy,the results showed that PbrC4H1 was localized on the cell membrane.