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Title: Identification of dihaploids in tall fescue utilizing capillary electrophresis

item Kindiger, Bryan

Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2013
Publication Date: N/A
Citation: N/A

Interpretive Summary: Grass forage development has lagged behind the major cereal crops in its degree of molecular marker analysis and approaches for genetic and agronomic improvements. Most selection and breeding of grass forages employ a traditional mass selection approach. Advances are being made in tall fescue development due to the identification and utilization of novel reproductive abnormalities which may be superior to traditional mass selection approaches. One novel, non-traditional selection and breeding approach that utilizes an annual ryegrass line, with novel chromosome loss behavior, has been effectively applied in generating inbred lines of tall fescue. When the tall fescue products generated from the hybridization process are complemented with a molecular marker DNA signature approach, differentiation between outcrossed and inbred lines can be readily identified. Though various means of differentiating individuals at the genetic level exist, a capillary electrophoresis system having a 2-5 bp resolution was shown to provide an efficient and effective level of discrimination. Results of the analysis using inbred and out-crossing tall fescue germplasm has identified that an automated capillary electrophoresis approach will rapidly provide differentiation between the two types of offspring with eight to ten molecular markers. The application of an capillary electrophoresis will facilitate the identification and selection of inbred lines of tall fescue and enhance the potential for development of F1 hybrid tall fescue cultivars or narrow based tall fescue synthetics. This information will be of interest and value to both commercial and public tall fescue breeders.

Technical Abstract: Innovations in tall fescue selection allow for the generation of dihaploid tall fescue lines. During the dihaploid generation process, two products are generated. These are tall fescue hybrids generated from outcrossing and homozygous dihaploid lines resulting from a parthenogenic, chromosome doubling phenomenon. As a means to rapidly differentiate between these two type of products, an automated Advanced Analytical CE capillary electrophoresis system was employed to evaluate various EST-SSR marker profiles. Dihaploid lines generated in a closed pollination area and two well characterized open-pollinated checks were submitted for analysis. The 2-5 bp fragment separation resolution for smaller EST-SSR fragments (100=250bp) was found to provide an acceptable level for discriminating between dihaploid and open-pollinated plant materials. The use of an automated capillary electrophoresis system can be efficiently utilized to enhance selection of tall fescue dihaploids. The analysis also provided valuable information with regard to the viability and receptivity of the embryos to fertilization by cross or open-pollination and the necessity for plant isolation during the dihaploid generation process.