Correlation Between The Quality Of Fuji Apples In Different Hues And Methylation Of Whole Genome After Bag Removal

In recent years,a series of researches on how to cultivate excellent Fuji apples has been a hot research field.It has been the goal pursued by a large number of researchers to cultivate Fuji apples with high-quality fruits and form a large-scale system,so to explore the quality of apples Which internal and external factors affect the disadvantage is particularly important.In this experiment,the ten-year-old "Fuji" was used as the parent material.To understand the changes in the physiological and biochemical indicators,genome-wide DNA methylation pattern distribution and related gene expression of Fuji apples(Striped Fuji and Blushed Fuji)fruits that affect the color of Fuji apples during the period from unbagging to complete coloring.1.Within 11 days after the Fuji apples were unbagged until the peel was completely colored,both external and internal quality changed,the surface finish index showed a downward trend,the peel color changed significantly,sugar acid content,vitamin C content,and volatile aroma substances occurred The change and the peak appear on the 8th to 9th days;by summarizing the physiological and biochemical index results of the Striped Fuji and Blushed Fuji and combining the clustering results and comprehensive analysis,the quality changes of Fuji apples from the time of unbagging to full coloring can be divided into Two stages: S1 quality change period(the first 8days)and S2 quality change period(the last 3 days);At the same time,optimized the evaluation system of Apple.2.MSAP analysis results showed that Fuji apples of different hues amplified a total of 942 methylation sites,and the genome-wide DNA methylation level averaged 31.16%;the methylation levels of type III and type IV were on the 8th to 9th days of bag removal The inflection point is obvious;the analysis of the methylation pattern changes in the two key periods of the quality changes of the Striped Fuji and Blushed Fuji fruits after unbagging.And the change trend is consistent.3.According to the correlation analysis,with the change of the number of days after bag removal,the Striped Fuji is significantly correlated with the type II methylationwithin 11 days of liquidation show that the various traits of Striped red Fuji are superior to Blushed red Fuji.The results of this paper confirmed that DNA methylation played a role in the changes of various fruit quality indicators from the unbagging of Fuji apples to complete coloring,in which demethylation participated in the process of fruit quality and flavor changes after unbagging of Fuji apples;The volatile aroma index that affects fruit quality is also correlated with methylation;the relative expression level of methylase gene is consistent with the change trend of methylation pattern,and the expression level of aroma-related structural genes is correlated with the results of measured volatile aroma changes Consistent;the overall quality of Striped Fuji fruit is better than Blushed Fuji.