Study On Content Changes Of Pigments During Fruit Development In Blood-flesh Peach And Its Heredity And Preliminary QTLs Analysis

Anthocyanins, a flavonoid subclass, are the main pigments in fruits and an important bioactive compound. Blood-flesh peach is very rarely and valuable, is a kind of the red flesh variety of germplasm resources. The blood-flesh, white flesh and yellow flesh of peach cultivars were taken as materials for studying the flesh color and the content changes of pigments, sugar and acid in the mesocarp during fruit development. Then, the anthocyanins, sugars and acids of 2 crossed combinations of hybrid F1 in Okubo×Tianjinshuimi and Shuguang×Tianjinshuimi were used for studying their inheritance trends. The results were as follows:Firstly, The results of this study suggested the contents of anthocyanins were notability difference between blood-flesh and no-blood-flesh of peach, and within blood-flesh cultivars. The result also showed that the anthocyanins contents of Tianjinshuimi were higher during the young fruit time, then decreased, until slowly to rise again in 45d DAFB (days after full bloom), and rapid increase after 86d DAFB. Secondly, the result showed that the inheritance of anthocyanins is a continuous partial distribution, and the progeny content of anthocyanins was more than that of parents, and tended to the more parents. Anthocyanin content is quantitative traits and controlled by a few main genes.Thridly, the color depth in the mesocarp was found to be an expression resulting from the effects of content of anthocyanins and titratable acid. The higher anthocyanin and titratable acid content, the reder the flesh. The rich sugar in flesh sufficient to ensure that anthocyanin synthesis, was not mainly affected anthocyanin contents and color of fruit flesh.Finally, two molecular linkage maps were constructed by SSR marker and SRAP marker, and a map covered a total length of 1536.9 cM with an average distance of 26.96 cM and another covered a total length of 1797.9 cM with an average distance of 17.12 cM. Four QTLs related to anthocyanins, soluble solids, soluble sugars and titriatable acids contents in the flesh were detected by using compostite interval maping. In Okubo×Tianjinshuimi, one QTL for anthocyanin content explained 11% of observed phenotypic variation, and one QTL for titriatable acid content explained 29% of observed phenotypic variation. In Okubo×Tianjinshuimi, one QTL for soluble solid content explained 23.07% of observed phenotypic variation, and one QTL for soluble sugar content explained 43.12% of observed phenotypic variation.