Effects Of Different Sugar Increasing Technical Measures On Fruit Quality And Sugar Core Formation In Red Fuji Apples

In recent years,Xinjiang has obvious advantages in industrialization of apples.Among them,Aksu’Red Fuji’apples have a long-standing reputation.Aksu’Red Fuji’apples have the advantages of large fruit size,good quality and long storage period,and their sugars accumulate in the core part.In this experiment,the’Red Fuji’apple from Wensu County,Aksu was used as the test material,processed through different sugar increasing technical measures,and picked in batches at the ripening stage of the fruit to determine the relevant indicators of sugar core formation and sugar accumulation,to clarify the relationship between the accumulation of sugar in apple fruit and the formation of"sugar heart",to analyze the key factors affecting the formation of"sugar heart"in apples,and to analyze the fruit quality,comprehensive analysis and comparison of the effects of different sugar-increasing technical measures on apple fruit quality and sugar core formation.to provide a certain theoretical basis for clarifying the formation factors of the’Red Fuji’apple candy heart,and then to provide a certain theoretical basis for promoting the high-quality and high-yield cultivation of the"Bingtangxin"apple in production.The results of the study are as follows:（1）The three different technical measures all increased the fruit weight,VC content,solid-acid ratio,soluble solid content,and improved fruit quality to varying degrees at the maturity stage of the fruit.All kinds of measures had obvious improvement effect on apple fruit quality,and the treatment with 200 mg/L GA₃had the best effect.（2）The three different sugar-increasing technical measures can significantly increase the sucrose content and sorbitol content of fruit at maturity,and the effects of Bihu treatment,200 mg/L GA₃treatment and 30cm spacing fruit thinning treatment are more significant;Bihu treatment and 30 cm Spacing and fruit thinning treatment can significantly increase the soluble sugar content and fructose content of fruit at maturity;different foliar fertilizer treatments and different concentrations of gibberellin can significantly increase the glucose content and sugar-acid ratio of apple fruit at maturity;In conclusion,the three different sugar-increasing technical measures all improved the sugar accumulation during fruit ripening to varying degrees.（3）Different foliar fertilizer treatments and different spacing fruit thinning treatments can significantly increase the activities of sucrose phosphate synthase（SPS）,sucrose synthase（SS）,acid invertase（AI）and neutral invertase（NI）at fruit ripening stage.On the whole,the effect of Bihu treatment and 30 cm spacing fruit thinning treatment was more significant;Bihu treatment,100 mg/L GA₃treatment and 30 cm spacing fruit thinning treatment could significantly increase the sorbitol dehydrogenase（SDH）activity in fruit ripening stage;Different concentrations of gibberellin can significantly increase the SS activity of apple fruit at maturity;200 mg/L GA₃treatment can significantly increase the SPS activity of apple fruit at maturity;In summary,the three different sugar-increasing technical measures all improved the activities of enzymes related to sugar metabolism during fruit ripening to varying degrees.（4）Different foliar fertilizer treatments can significantly increase the sugar heart rate of apple fruit,and the treatment effect of Bihu is more significant;Bihu treatment can significantly improve the sugar heart index of apple fruit at maturity;200 mg/L GA₃treatment,20 cm spacing The fruit treatment had a certain effect on improving the sugar heart rate and sugar heart index in the ripening stage of the fruit,but the effect was not significant.（5）The results of correlation analysis between sugar accumulation and sugar core formation in apple fruit showed that four enzymes,SPS,SS,AI and NI,were the key enzymes affecting the synthesis of sucrose and sorbitol during fruit ripening and development;two enzymes,AI and NI,are the key enzymes regulating fructose metabolism;sugar heart fruit rate,sugar heart index and soluble solid content,soluble sugar content,sucrose content,sorbitol content,The sugar-to-acid ratio and the activities of the four enzymes SPS,SS,AI and NI were significantly positively correlated（p<0.01）,but not significantly correlated with the glucose content and fructose content.It shows that the formation of"sugar heart"in’Red Fuji’apple is closely related to the accumulation of sugar,especially the accumulation of sucrose and sorbitol.The effect of"sugar heart"fruit rate and"sugar heart"index was greater than that of glucose and fructose content on apple’s"sugar heart"fruit rate and"sugar heart"index.The results of principal component analysis of apple fruit sugar accumulation and sugar core formation showed that three different technical measures had different effects on apple fruit sugar accumulation and sugar core formation,and the Bihu treatment reached the highest score,it showed that Bihu treatment had the best effect on improving the sugar accumulation and the formation of"sugar heart"in apple fruit.Based on the effects of various treatments on fruit quality,sugar accumulation and sugar core formation in the above research results,it is preliminarily speculated that the four enzymes SPS,SS,AI and NI in apple fruits under different sugar increasing technology measures can promote the accumulation of sucrose and sorbitol at the ripening stage.Among them,Bihu treatment has the best effect on improving sugar accumulation and sugar core formation in apple fruit.At the same time,Bihu treatment also significantly improves fruit quality.Therefore,Bihu is recommended as a foliar fertilizer to spray the best effect in actual production.