Cross potential selection: a proposal for optimizing crossing combinations in recurrent selection using the usefulness criterion of future inbred lines.

Abstract

In plant breeding programs, rapid production of novel varieties is highly desirable. Genomic selection allows the selection of superior individuals based on genomic estimated breeding values. However, it is worth noting that superior individuals may not always be superior parents. The choice of the crossing pair significantly influences the genotypic value of the resulting progeny. This study has introduced a new crossing strategy, termed cross potential selection, designed to expedite the production of novel varieties of inbred crops. Cross potential selection integrates fast recurrent selection and usefulness criterion to generate novel varieties. It considers the segregation of each crossing pair and computes the expected genotypic values of the top-performing individuals, assuming that the progeny distribution of genotypic values follows a normal distribution. It does not consider genetic diversity and focuses only on producing a novel variety as soon as possible. We simulated a 30-year breeding program in 2 scenarios, low heritability (h2=0.3) and high heritability (h2=0.6), to compare cross potential selection with 2 other selection strategies. Cross potential selection consistently demonstrated the highest genetic gains among the 3 strategies in early cycles. In the 3rd year of the breeding program with a high heritability (h2=0.6), cross potential selection exhibited the highest genetic gains, 138 times that of 300 independent breeding simulations. Regarding long-term improvement, the other selection strategies outperformed cross potential selection. Nevertheless, compared with the other 2 strategies, cross potential selection achieved significant short-term genetic improvements. Cross potential selection is a suitable breeding strategy for the rapid production of varieties within limited time and cost.