General combining abilities and stability analysis to assess the value of grain sorghum hybrids made across public and private sector breeding programs

Grain sorghum [Sorghum bicolor (L.) Moench] is an important crop worldwide, and in the United States, it is typically grown in drought prone environments. Sorghum has a rich history of public sector improvement by programs at Texas A&M University, Kansas State University, and the United States Department of Agriculture Agricultural Research Service among others. The discovery and development of hybrid grain sorghum in the 1950s privatized much of the sorghum breeding industry, but the public sector continues to make contributions to sorghum improvement. There is a need to assess the relative merits of different sorghum programs and their complementation. Within this context, this study evaluated the productivity of grain sorghum hybrids made across and within three public and one private sector breeding program. The parents consisted of 12 elite pollinators and 12 elite seed parents from each program crossed in a partial factorial to create over 1200 hybrids that were grown in 25 sparse trials from South Texas through northern Kansas in 2022 and 2023. The highest yielding hybrids were consistently produced using inbreds from different programs, which indicates that inbred exchange can increase hybrid productivity. In addition, the value of specific adaptation to a target region was made apparent by the increase in performance of programs in their primary selection environments. The study herein demonstrated that hybrids made between private and public breeding programs improved performance, highlighted the value of germplasm exchange between private and public sector programs, and encouraged private sector companies to explore the value of incorporating public material into their program.