ARS | Publication request: GENETIC DIVERSITY OF PUBLIC INBREDS OF SORGHUM DETERMINED BY MAPPED AFLP AND SSR MARKERS

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 2, 2004
Publication Date: June 1, 2004
Citation: Menz, M.A., Klein, R.R., Unruh, N.C., Rooney, W.L., Klein, P.E., Mullet, J.E. 2004. Genetic diversity of public inbreds of sorghum determined by mapped AFLP and SSR markers. Crop Science. 44:1236-1244.

Interpretive Summary: Plant genetics is a field of scientific research whose main purpose is to understand at the most complex and minute detail (the genetic level) just how plants live and function. With such understanding, better plant varieties can be developed to greatly improve the production of human foods and animal feed worldwide. We have conducted research on sorghum (a type of grass whose seed is used as a human food and animal feed), using very sophisticated and complex techniques of molecular biology. Results from our work will be very useful in aiding other scientists (plant breeders, etc.) to develop better plant varieties. Our work makes it easier to determine how plant breeders and nature have selected plants based on genetic information that the plant contains and how this selection has reduced the genetic variability of modern crop plants. The concepts we have presented will also be useful to other scientists working in other important grasses which include corn and wheat.

Technical Abstract: The amount of genetic diversity in public inbreds of sorghum is unknown yet detailed knowledge of the diversity among existing public lines could improve the effectiveness of programs developing lines for use in hybrid development programs. With the development of saturated genetic maps and high-throughput marker systems, it is now feasible to deatail the genetic diversity for a defined chromosomal region by constructing high-resolution marker haplotypes for any number of selected genotypes. Microsatellites and pedigree data were utilized to determine the genetic diversity in a group of sterility maintainer and fertility restorer public inbreds and compare the estimates of genetic diversity to a group of exotic lines from the World Collection. Marker haplotypes were also constructed for the chromosomes of BTx623 and RTx430, two inbreds of sorghum with excellent combining ability. The objectives of these studies were to obtain knowledge of the level of genetic diversity in R- and B-lines and determine whether this genetic diversity is being effectively utilized in hybrid production, and to constuct high-resolution marker haplotypes of the genome of sorghum and characterize the allelic diversity between sorghum inbreds at the sub-genomic level.