Inheritance trend of the fruit traits of F1 grape progenies of two crossing combinations with '2-1-3' (Vitis quinquangularis×Vitis vinifera) as the female parent

Abstract: 【Objective】Breeding new grape varieties is very important for promoting grape industry. In order to explore the genetic laws of fruit traits in wine grapes and to improve predictability and breeding efficiency of grape crossbreeding, we researched the genetic tendency and analyzed the inheritance of the fruit traits of 69 hybrid plants generated from hybridizing'2-1-3' (Vitis quinquangularis Rehd.×Vitis vinifera) with 2 wine grape varieties.【Methods】2 crossing combinations hybridization was made using'2-1-3'as female parent in 2007 and 69 F1 progenies were obtained. The hybrid plants bore berries in 2012. The berries were collected from grape vines grown in the vineyards of Pomology Institute, Shanxi Academy of Agricultural Science in Taigu, Shanxi province during August to October in 4 years (2013—2016) . The fruit quality indexes of berry weight, the ratio of peel and pulp, soluble solids (SS) , titratable acid (TA) content, pH value, juice yield in fresh fruits were measured according to the conventional method. The samples were frozen using liquid nitrogen and stored in an ultra-low temperaturefreezer. The contents of phenolic compounds in skin, pulp and seeds of berries were analyzed for 4 years according to colorimetric method. The data were processed by Excel statistical software, and the genetic tendency of fruit characteristics were analyzed by the indexes of coefficient variation (CV) , heritability (Ta) , heterotic rate.【Results】In the crossing combinations of'2-1-3'×'Areni'and'2-1-3'×'Ruby Cabernet', the fruit characteristics of F1 progeny were quantitative traits with continuous distribution, the value of CV in the 21 fruit indexes was 3.18%-142.98%, 6.87%-109.75%, respectively, especially the value of CV of the fruit shape index, pH value and juice yield were below 10%, while the value of CV the Ta was 50.18%-235.89%, 73.77%-146.0%, respectively. The average berry weight of F1 progenies was slightly above the mid-parent value, there were some ultra high individuals, but more than half progeny had mid berry weight between parents' value (56.67%, 73.81% respectively in the crossing combinations of'2-1-3'×'Areni'and'2-1-3'×'Ruby Cabernet') . The SS content of F1 progenies was higher than the mid-parent value, the proportion of progeny which had mid SS content between parents' value in the crossing combination of'2-1-3'×'Areni'was more the half (51.85%) , while the proportion of progeny which has SS content higher than parents in the crossing combination of'2-1-3'×'Ruby Cabernet'was largest (47.62%) . The TA content of F1 progenies was lower than the mid-parent value, and the proportion of progeny which had TA content lower than parents' value was51.85%, 50.0% respectively in the crossing combinations of'2-1-3'×'Areni'and'2-1-3'×'Ruby Cabernet'. The average total anthocyanin content of F1 progenies was lower than that of the parent with low content, and the proportion of progeny which had lower content than parents' value was larger than60%. In the crossing combination of'2-1-3'×'Areni', the mean values of proanthocyanidins content in the skin, total phenols, total flavonoids, and proanthocyanidins content in the pulp of F1 progenies were higher than their mid-parent values, and the proportion of progeny which had higher content than parents' value was 48.15%, 44.44%, 55.56%, 55.56%, respectively; the average value of the other phenolic indicators was lower than their mid-parent values, the proportion of progeny which had the phenolic content between the parents in the seeds was relatively larger, however, the proportion of progeny which has the phenolic content below the parents in the remaining 4 indicators was larger. In the crossing combination of'2-1-3'×'Ruby Cabernet', the content of phenolic compounds in skin, total phenolics, tannins and proanthocyanidin content in pulp of the progeny was lower than the mid-parent value, and the proportion of progeny which had the proanthocyanidin content in pulp between the parents was the largest, however, the proportion of progeny which had the lower content in the other indicators than the parents was the lowest; the average content of the other phenolic compounds in pulp and seeds was higher than the mid-parent value, and the proportion of progeny which had contents between the parents was the largest.【Conclusion】The mean value of berry weight in the two crossing combinations was slightly higher than the mid-parent value, and there had emergence of super-high progeny. The average SS content of F1 progenies was higher than the mid-parent value; in addition to the additive effect of the genes, there was a certain non-additive effect and a certain heterosis. The mean TA content of F1 progenies was lower than the mid-parent value, tending towards the low acid parent. The genetic tendencies of the two crossing combinations in phenolic compounds were somehow different. This may be due to the difference in the combination type and the difference in the genetic tendency of the traits.