Comparison and Genetic Variation Analysis of Important Fruit Traits in Jujube F1 Hybrids by Different Male Parents

The research on the genetic predisposition of key quality traits of fruit in jujube hybrid populations is a fundamental and crucial aspect in the field of jujube genetic breeding. In this study, the jujube hybridization experiments were conducted with the same female parent and different male parents since 2015, and a total of 238 strains were created in two F1 hybrid populations. The genetic variation of fruit external traits and intrinsic quality was analyzed and compared after the hybrid offspring results were stable in 2022. This study can provide a theoretical basis for selecting hybrid-breeding parents, predicting offspring traits, and innovating excellent germplasm resources by investigating the impact of different male parental configurations on the genetic variation of fruit traits in jujube hybrid offspring and identifying superior germplasm resources. The results showed that the inheritance of fruit shape, fruit size, and fruit-intrinsic nutrition-quality traits were quantitative traits controlled by multiple genes, and the offspring populations conformed to normal distribution or partial normal distribution. The six traits of fruit shape in offspring populations exhibited a segregation from their parents. The coefficients of variation of fruit size and intrinsic nutrition quality values ranged from 6.94% to 35.34%. Five intrinsic nutrition-quality traits exhibited significant separation at the super-parental level. This result indicated a rich genetic diversity in offspring traits in two hybrids offsprings. The fruit shape, fruit size, and titratable acidity of jujube hybrid offspring were mainly influenced by the male parent. It was found that the correlation between the single-fruit weight, length, and diameter, as well as the correlation between the fruit length and fruit transverse diameter, was very stable and significantly positive through the correlation analysis. More attention should be paid to fruit length when studying fruit shape, as a significant correlation was found between fruit length and fruit shape index. Finally, 10 superior hybrids were founded and selected as breeding materials for further breeding. Therefore, this study provides a theoretical basis for the early selection of hybrid breeding and the development and application of jujube germplasm resources.