Combining abilities and elite germplasm enhancement across US public sorghum breeding programs

Authors: FONSECA, JALES M - Texas A&M University; PERUMAL, RAMASAMY - Kansas State University; KLEIN, PATRICIA - Texas A&M University; Klein, Robert - Bob; ROONEY, WILLIAM - Texas A&M University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/30/2021
Publication Date: 10/30/2021
Citation: Fonseca, J.O., Perumal, R., Klein, P.E., Klein, R.R., Rooney, W.L. 2021. Combining abilities and elite germplasm enhancement across US public sorghum breeding programs. Crop Science. 61:4098-4111. https://doi.org/10.1002/csc2.20624.
DOI: https://doi.org/10.1002/csc2.20624

Interpretive Summary: The yield potential in grain sorghum hybrids has increased at a slower rate than other cereal crops including its close relative maize. While there are many reasons for this lag, sorghum's hybrid performance issue may be addressed in part through the exchange of elite germplasm between geographically distinct public breeding programs. In this study, we produced and tested hybrids from elite female and male lines originating from Texas A&M University and from Kansas State University. The results demonstrated the potential benefit from crossing elite inbred parents derived from distinct breeding programs to increase genetic variation and enhance agronomic performance. Further, these crosses could foster collaborative efforts between other public institutions to enhance the rate of genetic gain in crops with limited public and private resources.

Technical Abstract: For mature breeding programs, maintaining genetic variation in elite germplasm requires a continual assessment of the most efficient methods to maximize functional genetic variation while improving productivity. This research assessed the relative value (defined as population means and variances) derived from elite germplasm exchange between distinct public breeding programs. Ten elite A- and R-lines from Texas A&M University and Kansas State University sorghum breeding programs were crossed in a factorial design to generate 100 hybrids. Hybrid combinations were grouped to represent hybrids within and across programs. Grain yield, plant height, and days to anthesis were measured in ten environments over two years. Combining abilities and their interactions with the environment were assessed. Combined analysis detected significant effects for all traits, but genetic effects for grain yield were not consistently significant within each group of hybrid combinations. Hybrids derived from only Texas inbreds had limited genetic variation for grain yield but the highest mean of all four groups; hybrids derived from only Kansas inbreds produced moderate genetic variation but lower grain yield potential. Maximum genetic variation for grain yield and plant height occurred when Kansas A-lines were crossed to Texas R-lines, whereas hybrids between Texas A-lines and Kansas R-lines maximized variation for days to antheses. Results demonstrated the potential benefit from crossing elite inbred parents derived from distinct breeding programs to increase genetic variation and enhance agronomic performance. Further, these crosses could foster collaborative efforts between public institutions to enhance the rate of genetic gain in crops with limited public and private resources.