Genetic analysis of fruit traits in Actinidia rufa (Siebold and Zuccarini) Planchon ex Miquel × Actinidia chinensis var. chinensis C. F. Liang kiwifruit hybrid population

Genetic analysis of fruit traits in hybrid populations of kiwifruit (Actinidia) can provide a theoretical basis for hybridization breeding. Here, we measured nine traits of fruit quality and shape characteristics of an F₁ population generated through hybridization between a female A. rufa '63101’ parent and male A. chinensis 'Moshan male No. 7’ parent. Results showed that average fruit mass of the F₁ population was lower than that of their parents, indicating a genetic tendency of regressing to small fruit. Average content of soluble solids was higher than the median content in parents, showing a genetic tendency to a higher level. The fruit shape of F₁ showed five segregated traits, 82% of which were the same as the female parent (cylinder). Fruit hairiness of F₁ showed a genetic tendency toward the male parent, with 60% and 40% being piliferous and glabrous, respectively. Skin color was characterized as green, greenish brown, or brown, at a ratio of 1.0∶1.5∶1.0. Shoulder shape at the stalk end was mainly square and outer pericarp color was mainly green, showing genetic tendencies toward the female parent (63% and 86%, respectively). For fruit flavors of the F₁ population, 64% were identical to the parents, 1% were extremely sour, and 9% were highly sweet. These results indicated that the hybrids showed a genetic tendency toward smaller fruit mass and higher soluble solid content. Fruit shape, shoulder shape at stalk, and color of outer pericarp showed genetic tendencies toward the female parent, but fruit hair showed a genetic deviation from the female parent. Fruit flavors showed wide separation, with some strains exceeding the parents. Thus, these progenies exhibit potential superiority.