Genetic segregation of sugar and acid contents in the fruits of F1 progenies derived from Jinhuang× Renong No. 1 of mango

Abstract:【Objective】Mango (Mangifera indica L.) is an important tropical and subtropical fruit and one of the fifth famous fruits in the world. Cross breeding is an important method for breeding new mango cultivars. At present, some cultivars have been bred through hybridization breeding. However, less attention has been paid to the genetic trend of fruit quality traits in mango hybrid progenies. It is necessary to explore the inheritance of internal quality traits in the fruits of mango hybrid population. Therefore, this experiment was carried out to uncover the inheritance of fruit quality traits including sugar, acid, carotenoids and total flavonoids, in order to provide a scientific basis for the selection of parents in cross breeding.【Methods】Forty-seven individuals of F1 population derived from a cross between Jinhuang (female, high-sugar variety) and Renong No.1 (male, low-sugar variety) were used as materials. Mature fruits were collected in 2021, then stored at room temperature, and fully ripen fruits were used for fruit internal quality analysis. Fifteen fruits from each tree were sampled, and divided into three biological replicates for quality traits measurement. The contents of sucrose, fructose, glucose, ascorbic acid, acetic acid, formic acid, citric acid, oxalic acid, tartaric acid and maleic acid of the fruitswere determined with high performance liquid chromatography (HPLC) method. The contents of carotenoids and total flavonoids were determined by UV spectrophotometer. The genetic variations of the fruit traits were evaluated by coefficient variation (CV), genetic transmitting ability (Ta) and heterobeltiosis, and frequency distribution map was used to investigate the inheritance tendency of the progenies. The data were processed using Microsoft Excel 2016.【Results】The sucrose, fructose and glucose were the main sugar components, the ascorbic acid, malic acid, acetic acid and citric acid were the main organic acid components in the fruits of the parents and their F1 offsprings. The individuals of the F1 populations exhibited a wide phenotypic variation in the sugar (sucrose fructose, glucose and total sugar), acids (ascorbic acid, malic acid, acetic acid, citric acid, formic acid, oxalic acid, tartaric acid and total acids), carotenoids and total flavonoids. The average coefficients of variation of the sugar and acid contents were over 32.88% and 140.53% respectively, and the range of acid contents was higher than that of sugar contents, indicating that there was a bigger selecting potential for the acid content. The coefficients of variation of the carotenoids and total flavonoids were 51.68% and 38.2% respectively, indicating that carotenoids had greater selection potential. Additionally, the genetic transmitting ability (Ta) of the sugars, acids, carotenoids and total flavonoids ranged from 9.73% to 222.52% (ascorbic acid), indicating that the variations of these traits mainly determined by the inheritance. The total sugar contents of progenies were higher than mid-parental value, and the super parent rate was over 38.30%, displaying obvious heterosis. However, the total acid contents inclined to low acid parent value, and the superlow parent rate was over 57.45%, showing a tendency of depression. There were more individual plants with higher content of carotenoids compared with the parents, and its super parent rate was 65.96%. The average flavonoids content of progenies was lower than that of the parents, and the low parent rate was 53.19%. The distributions of the total sugar, carotenoids and total flavonoids in the F1 progenies were close to the normal distribution, indicating that these three traits were quantitative traits controlled by multiple genes. Nevertheless, the acid content of the hybrid offsprings displayed skewed distribution, implying that the acid contents might be controlled by one or more major genes.【Conclusion】 The sugar, carotenoids and total flavonoids were quantitative traits controlled by multiple genes, whereas the organic acids were quantitative traits controlled by one or more major genes. The contents of sugar and acid in the fruits of mango hybrid progenies were closer to the parent with high-sugar and low-acid content, and were prone to be affected by the female parent, the inheritance of the carotenoids was inclined to the high value parent, and was greatly influenced by the male parent. The inheritance of the total flavonoids tended to be similar to the low-value parent, and was prone to be influenced by the female parent.