Genetic Mechanisms that Allow Hybrids to Perform Better than their Parents

An agronomist from Iowa State University has uncovered the genetic mechanisms in sorghum plants that allow heterosis, a process where hybrids perform better than their parents. The precise genetic process behind heterosis is only partially understood, so agronomy Professor Jianming Yu and his colleagues worked to pin down how heterosis works on plant height in sorghum plants.

The study focused on repulsion phase linkage, or the link between a dominant allele of one gene with the recessive allele of another gene. To explain where the extra height comes from, Yu explained that the genes of inbred plants sometimes cancel each other out. Combining the right varieties means those genes are no longer canceling each other out, unleashing the potential for desirable traits to manifest in the hybrid.

He also said that multiple genes govern a sorghum plant's total height. For instance, some genes may only influence the base of the plant, while other genes affect the entire plant. Untangling all those connections also points to how hybrids may outperform both parent varieties, he said.

For more, read the news article at the Iowa State University News Service.