The Genetic Identification And Fruit Quality Analysis Of The Variations In Citrus

Citrus is the most important fruit crops in China. At present, there is still lack of late mature cultivars for processing, the supply of fresh edible fruit is concentrated. In this research, we find two mutation to fill in the blanks of the market, provide contributions to improve the citrus varieties in China.In this study, we used AFLP to perform genetic identification with the mutation of late mature Jincheng Orange [Citrus.sinensis.(L.)Osbeck] found in XingShan, and the fresh edible variation of Valencia Sweet Orange [Citrus. sinensis.(L.)Osbeck] cultivars foung in ZiGui. Polymorphisms between the mutation and the original were found out. Quality analysis were also performed,there is little difference in fruit quality between the mutation and the original in Jincheng Orange,the processing quality shows no change; at the same time, the mutation of Valencia Sweet Orange cultivars has potential to be introduced as edible cultivars which shows better edible characters such as seedless, high solid-acid ratio.The main research results are as follows:1. Ploidy identification of the Valencia Sweet Orange cultivars was performed by flow cytometry, and the result shows the mutation was diploid, the same as the original.120 pairs of AFLP primers were used, and there are 16 polymorphism bands we found between the mutation and the original in Jincheng Orange,2 between the variation and the original in Valencia Sweet Orange cultivars. All of the polymorphism bands sequences were measured, and from which the primers designed to amplified in the mutations and the originals. Some primers were able to get amplified successfully which shows the truth of the polymorphism between the mutations and the originals. As the proof of mutant.2. There shows little differences in common quality between the variation of Jincheng Orange. For main processing quality,the juice yield was 38%, the TSS was 11.27%, TA was 1.19%, and the amount of Vc was 52.55mg/100g,which meet the requirements of processing. Analysis of sugar to acid by GC shows little differences between the mutation and the original neither. The mutation of Valencia Sweet Orange cultivars shows larger firut (length8.82cm, & width 8.65cm), seedless, high sugar-acid ratio (14.84). The malic acid (0.71mg/g) and the sucroce (43.71mg/g) of the mutation were higher than the original. The citrus acid (3.02mg/g) was less than the original, which constitute the flavor of the mutation fruit.It has potential to be introduced as fresh edible cultivars.