Breeding for partial resistance to crown rust: We have developed a population segregating for alleles conferring good yield and agronomic adaptation and partial resistance to crown rust. We are evaluating 200 S1-derived lines in trials at 3 locations in Iowa. At each location, 3 replications are inoculated with Puccinia coronata, and 3 replications are maintained rust-free by spraying a systemic fungicide. We plan to develop a selection index to improve yield and test weight potential under both rust infestation and rust-free conditions and to intermate selected lines this fall. Mr. John Shriver and Dr. Gary Munkvold of the Dep. of Plant Pathology collaborate on this research.
Intercropping oats and annual legume forages: We are testing all possible binary combinations of five small grain cultivars and five annual forage legumes plus monocultures of each cultivar under two management regimes: harvesting small grains for grain or for forage. Results from previous 3 years indicate that intercropping performance varies greatly among oat cultivars, but is not a simple function of plant height or maturity. For some traits, interactions between small grain and forage cultivars have been detected, suggesting that selection for optimum intercrops should be performed simultaneously in the two component species. We are initiating experiments this summer to determine the effects of species and "ecological functional group" diversities on mean productivity and yield stability in intercrops of varying complexity. Does such diversity enhance agricultural stability or performance? In collaboration with Dr. E. Charles Brummer we hope to be able to answer this question. Sara Helland has begun work on a M.S. project to investigate the effect of intraspecific genetic variation in oat on yield and yield stability of cultivar blends.
Breeding for high b-glucan content in oat grain:Dr. K.J. Frey developed a broad-based oat population in which selection for enhanced b-glucan content was conducted for three cycles in cooperation with Dr. D.E. Wesenberg of the USDA-ARS, Aberdeen, ID, and Dr. P.J. White of the Dep. of Food Science at ISU. Mr. Cuauhtemoc Cervantes, a Ph.D. student, is evaluating the effects of selection on b-glucan content, grain yield, and other agronomic trait means and heritabilities. First-year results indicate that b-glucan content was increased significantly with each cycle of selection.
Breeding for broad-adaptation in oat:In cooperation with Dr. Åsmund Bjørnstad of the Agricultural Univ. of Norway, and with Dr. Wesenberg, we have conducted 5 cycles of selection for adaptation to diverse environments in a broad-based oat population developed by Dr. Frey. Results from the first three cycles indicate that selection increased both grain yield averaged over all environments (Iowa, Idaho, and Norway) and within each environment. Broadly-adapted lines from the 3rd cycle of selection were identified, and evidence that selection enhanced the stability of grain yield over environments was obtained. The best lines from this program are being incorporated into oat breeding programs in Iowa and Norway.
Oat lipase: H oi Sio-Wai completed his M.S. thesis on the heritability of lipase activity in oat. Heritability on a sample basis was estimated to be 0.22, but on a line mean basis averaged over six environments was estimated as 0.63. No significant genetic correlation was observed between lipase activity and yield or test weight, suggesting that high or low lipase activity oat cultivars with good agronomic adaptation could be developed. Dr. E.G. Hammond in the Dep. of Food Science, ISU, cooperated on this work, and he has suggested a method to replace current energy-intensive industrial catalysis of the lipase reaction in soap production with oat groats with high lipase activity.
Genome mapping: Dr. V. Portyanko is working in cooperation with Dr. M. Lee of ISU and Dr. D. Hoffman of USDA-ARS, Aberdeen, ID, on a genomic map of a recombinant inbred population derived from the cross of TAM-0-301 winter oat by Ogle spring oat. We have evaluated this population under different vernalization and photoperiod treatments in the growth chamber and under different planting dates and environmental conditions in the field. We hope to develop a framework genetic map for comparative mapping of hexaploid oat to diploid oat and related grass genera and for mapping QTLs affecting agronomic performance under different environmental conditions. Charles Kremer, an M.S. student, is developing a similar map in a diploid Avena recombinant inbred population in order to enhance our understanding of genomic relationships within Avena and between oat and related grass genomes.