Although plant breeders are experts in evaluating and understanding their crop, the worst mistake many breeders make is selecting parents without considering their impact on the hybrid. Excellent parents often produce unsuccessful hybrids; on the other hand, successful varieties can result from parents that performed poorly.
What you observe in the parents is not what you observe in the hybrids.
Neglecting Phenotypic Data
When planning new hybrids, many breeders filter parents based on phenotypic data to create new hybrid combinations. The problem with that is that it neglects the effect of these parents on hybrids. This mysterious effect is called “combining ability.” Instead of searching parents that “perform well in trait X and in trait Y,” you should search for parents where their hybrids “perform well in trait X and trait Y.” The criteria for selecting parents should be based on how they affect their hybrids, and not on their own performance. For this, we need to use all existing data. Each hybrid previously observed has something to teach us about its corresponding parents.
The tricky part is that parents’ impact on hybrids across a range of traits is not easy to deduce and requires cross referencing to previous generations and past observations. The inability to do this not only means losing data that you already spent time and effort collecting, but more importantly, leads you to making the wrong decisions. This is equivalent to selecting based on a gut-feeling and trial-and-error instead of data-driven, educated decisions.
Key Questions
At any point in your breeding program, you should ask: What have I learned about the parents from my past hybrid observations? What is the combining ability of a given parent for a specific trait? What did each parent contribute and to which phenotypes? If you can’t answer these questions, how will you develop better hybrids in the next season? If you cannot learn from your existing data, you are less likely to make a genetic gain and release market breakthrough varieties.
But don’t despair. Specialized plant breeding software, which is designed to capture the true breeding values of your lines, can be a game changer in the success of your breeding program.
