H.F. Kaeppler, R.D. Duerst, E.O. Oplinger, R.W. Skadsen, D.M. Peterson
Department of Agronomy, University of Wisconsin, Madison, WI 53706
Production: Wisconsin farmers planted 510,000 acres of oats in 1997, accounting for about 10% of the U.S. oat acreage. Approximately 330,000 acres of Wisconsin oats were harvested for grain and straw in 1997. The majority of the remaining oat acreage was harvested for forage. Oat acreage was about 3% higher in 1997 than 1996. Projected oat acreage for 1998 is between 480,000-500,000 acres, down slightly from 1997. The average oat yield in 1997 was 63 bushels per acre, up 5 bushels per acre over 1996. Cool temperatures and adequate rainfall during the 1997 growing season contributed to the increased yields. Crown rust was prevalent throughout the majority of the oat growing area in Wisconsin, contributing to lower yields in rust susceptible oat varieties. Stem rust was detected, but severity was low resulting in low overall impact on yield.
Varieties: Acreage of oats grown by Certified Seed producers in 1997 indicate that Gem, Dane, and Belle will be the leading varieties grown in 1998. The newest of the three varieties, Gem, was released to Certified Seed growers in 1996 and was grown by commercial producers for the first time in 1997. Gem is a high yielding, midseason variety resistant to crown rust races present in Wisconsin.
A major increase of Wisconsin test selection X6165-5 was produced in 1997 and will again be increased in 1998. Line X6165-6 is high yielding, late maturing and highly resistant to crown rust under Wisconsin growing conditions.

Genetic Engineering of Oat:  Dr. Geeta Menon, a postdoctoral research associate, has been conducting research on the optimization of novel selection systems for transgenic oat and the transformation of oat with genes encoding antifungal proteins. An efficient system for selection of transgenic oat cultures using only visual selection for expression of the green fluorescent protein (GFP) gene has been developed and is being routinely utilized to generate fertile, transgenic plants. Transgene integration was confirmed using Southern blot and PCR procedures. GFP expression was determined visually. Progeny of transgenic plants analyzed to date display high level expression of the GFP gene segregating in a normal, 3:1 (expressing:nonexpressing), Mendelian ratio for a dominant, heterozygous gene. In collaborative research with Dr. Dave Somers, University of Minnesota, fertile transgenic plants of elite oat varieties such as Belle and Dane were generated using model marker genes. Efforts are now underway to transform elite varieties with agronomically useful transgenes. Fertile, transgenic plants containing a transgene encoding a thaumatin-like, PR-5, protein have been generated and are undergoing expression and inheritance analysis. Transgenic lines expressing the antifungal gene will be tested for enhanced resistance to crown rust in seedling and adult plant assays in collaboration with Dr. Kurt Leonard, USDA-ARS Cereal Disease Research Unit, St. Paul, MN. Plantlets containing a second, unrelated antifungal transgene are being regenerated at this time and will soon be moved to rooting medium.
Mapping Crown Rust Resistance Genes Using Molecular Markers: Mr. Shuquan Zhu, working on his Ph.D. in Plant Breeding and Plant Genetics, is conducting research with the goal of mapping crown rust resistance genes in oat using molecular markers (RFLP's, AFLP's). A population segregating for crown rust resistance, introgressed from diploid wild oat (Avena strigosa) into a cultivated, hexaploid oat background, was created by crossing crown rust susceptible oat variety 'Ogle' with the crown rust resistant line MAM17-5. Results from genetic inheritance studies conducted on this population by former Ph.D. student Miglena Dilkova (under the direction of Dr. R.A. Forsberg) indicated that major genes for resistance to crown rust were segregating in this population. The population was reconstructed and notes taken on rust reactions of field grown F2 plants in a heavy rust year (1996). Field grown F3 lines were also observed under heavy rust pressure in 1997, to confirm F2 classification. Lines were advanced via single seed decent to the F6 generation in the Fall 1997 and Winter 1998 greenhouse growouts. F6 headrows will be grown in the field in 1998 for observation, scoring, and seed increase for use in replicated trials in 1999-2000. Seed is also being increased in Aberdeen, ID by collaborator Dr. Darrell Wesenberg, under lower disease and rust pressure. F7 lines will be tested and scored for rust resistance using seedling assays by collaborator Dr. Kurt Leonard, at the USDA-ARS Cereal Disease Laboratory, St. Paul, MN. Screening blots are being conducted to identify RFLP probes which are polymorphic between the parent lines. Genomic DNA will be isolated from greenhouse-grown plants of the lines in the population during the summer and fall of 1998.


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