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United States Department of Agriculture

Agricultural Research Service


Location: Crop Germplasm Research

2008 Annual Report

1a. Objectives (from AD-416)
Objective 1: Develop and evaluate improved grass germplasm for the southern U.S. that is more productive, biologically diverse, tolerant of biotic and abiotic stresses, improved in quality, and easier to establish and maintain in pastures and rural landscapes. Sub-objective 1.A: Develop and evaluate kleingrass (Panicum coloratum) germplasm with improved forage yield, seedling vigor, and persistence. Sub-objective 1.B: Produce intraspecific Paspalum hybrids between different dallisgrass biotypes to develop improved forage types. Sub-objective 1.C: Identify superior Texas bluegrass (Poa arachnifera) genotypes that are rust resistant and adapted to the humid southeastern U.S. to develop a synthetic population from these genotypes. Objective 2: Use genomic techniques to develop and identify molecular markers associated with traits of interest in forage and turf grasses. Sub-objective 2.A: Identify molecular markers to further saturate the genomic region controlling apomixis and survey candidate genes for seed sterility in buffelgrass (Pennisetum ciliare). Sub-objective 2.B: Develop a genetic map of dallisgrass (Paspalum dilatatum) to identify markers linked to apomixis, disease and insect resistance, and other traits of interest. Objective 3: Develop improved breeding methodologies by determining the cytology, reproductive biology, and genetic diversity of native and introduced germplasm for the production of improved forage and turf grasses. Sub-objective 3.A: Determine the method of pollination, chromosome number, ploidy level, and mode of reproduction of species in the genera Panicum, Paspalum, Pennisetum, Sorghum, Chloris, Setaria, Stenotaphrum, Tripsacum, and others to facilitate their genetic improvement. Sub-objective 3.B: Determine the genetic diversity and phylogeny of Paspalum and Pennisetum species using DNA fingerprinting techniques.

1b. Approach (from AD-416)
The long-term objectives of this project are to obtain a better understanding of the cytology, reproductive biology, and genetic diversity of selected forage grasses, and to use this fundamental information in the breeding and development of superior germplasm that will be released as improved cultivars.

3. Progress Report
This is a new project that replaced the bridging project 6202-21000-026-00D and which is continuing and expanding upon the work of the bridging and its precursor (6202-21000-020-00D) projects. In FY 2008, work under this project established the cytology and reproductive behavior of 20 accessions of five different Paspalum species. Data on chromosome number, ploidy level, meiotic behavior, and mode of reproduction is essential in determining how these species/accessions can be used in the project's Paspalum hybridization program. Texas bluegrass (Poa arachnifera) plants that are superior for vegetative spread, sod density, biomass production, and resistance to rust were selected from a space-planted nursery at Rosepine, LA. These plants will be used as the base population to breed a more productive, rust-resistant synthetic bluegrass population that is adapted to the humid southeast. In ongoing kleingrass (Panicum coloratum) work, seed were collected from 12 kleingrass lines in a recurrent selection polycross block consisting of 12 replications, and were bulked by maternal parent. These seed will be used for the next cycle of selection. (NP 215, Component 2, Problem Statements D.1, D.2)

4. Accomplishments

Review Publications
Kuhlman, L.C., Burson, B.L., Klein, P.E., Klein, R.R., Stelly, D.M., Price, H.J., Rooney, W.L. 2008. Genetic recombination in Sorghum bicolor x S. macrospermum interspecific hybrids. Genome. 51:749-756.

Last Modified: 10/18/2017
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