NON-TECHNICAL SUMMARY: The US has been a net importer of oat grain since 1982. At the same time there are a number of crop production problems in the Upper Midwest that are exacerbated by very short rotations. Oat is a very good break crop for causal pests and thus it may be possible to address both problems by including oat more often in the cropping systems. The ultimate purpose of this project is to develop oat cultivars that will fit better in more ecologically sound cropping systems and that have enhanced-value grain.

OBJECTIVES: 1)Develop oat cultivars with improved milling yield and with durable pest resistance and/or with greater tolerance to reduced tillage establishment; 2)Continue development of recurrent selection protocols; 3)Identify and verify useful molecular markers especially for partial crown rust resistance and for frequency of tertiary kernels

APPROACH: Development of new cultivars is a cooperative effort that spans from Minnesota to Australia. Specific selection criteria will emphasize milling yield and durable disease resistance. Grain yield, lodging resistance, BYDV tolerance and increased competitiveness with grassy weeds will also receive attention. Crosses will be made between cultivars and other elite genotypes and also with parents from our recurrent selection populations. F1 plants will be grown in the greenhouse or at Aberdeen ID. Beginning in the F2 and on to F5-6 generations, the progenies will be alternately grown in MN and in New Zealand. The MN grow outs will be inoculated with crown rust at heading and the NZ plots will be naturally exposed to rust and BYDV. Surviving lines will be entered into Preliminary Yield Trials, then Advanced, then State Variety and then Regional Nurseries. For selection for weed competitiveness, yield trials at Morris MN will be divided into Foxtail infested and Foxtail managed replicates, at least two of each. Relative grain yields and Foxtail production (infested vs. managed) values will be used to identify strong and weak competitor/suppressor genotypes. Intercrosses within each group will be made to intensify the level of trait expression. We will acquire a no-till experimental plot drill to seed some of our yield trials. Initial evaluations will focus on comparative emergence and seedling vigor. Germplasm development will be mainly two efforts with 3-way crosses and their segregating populations. For one group the core cross will be Winter x Spring types and that F1 will be crossed to a "locally adapted" line, especially from programs that do not have adequate resources to do their own crossing. The second group will be crosses among partial rust resistant lines from Purdue, from UFRGS in Brazil, and from MN. We will maintain a balanced input from the three programs to ensure retaining desired loci from each. The recurrent selection efforts will be continued in two ways. First, the selection primarily for grain in the Closed Crossing populations will be continued into the 9th cycle, probably testing in F4 instead of F6 to reduce the cycle time from 3 to 2 years. This material will also be subjected to a natural crown rust infection at Rosemount, MN to select for higher levels of partial resistance. These two approaches will then be compared for combined levels of the two traits. The second effort will continue the double and 3-way crosses from the Opened Crossing system. Selection emphasis will be on the composite value of several traits of interest, including grain quality that has deteriorated because of single (yield) trait selection. Identification, verification and utilization of molecular markers will be focused on two traits, partial crown rust resistance and frequency of tertiary kernels. Most of this effort will be devoted to determining if markers identified in the KxO mapping population are also appropriately present in breeding materials and in recurrent selection populations. If present, MAS will be utilized in breeding efforts when it is cost effective to do so.

KEYWORDS: recurrent selection; oats; cultivars; plant disease resistance; weeds; competition; plant breeding; plant genetics; crown rust; crop yields

PROGRESS: 2006/01 TO 2006/12
Mn02234, Sesqui x OA982-6, was approved by the MN AES for final increase, and projected release in early 2008. This line has equaled or bettered every entry in the multiple year summaries of our Minnesota Variety Trials beginning with 2003. The only entry to exceed it statistically for grain yield in any multiple year comparison is Stallion, a new release from South Dakota. When compared to Stallion for all other measured traits, Mn02234 exceeds Stallion for lodging resistance, test weight, groat percent, crown rust and smut resistance. It is inferior for only Barley Yellow Dwarf Virus (BYDV) ratings, in addition to grain yield. Thus, for available cultivars, and considering all traits evaluated, Mn02234 is the best entry tested. Moreover, its crown rust reaction appears to be such that is might be more durable than that of many of our other lines with more than single major gene resistance. For other grain quality traits, Mn02234 has lower than average fat content, somewhat above average beta-glucan (fiber) content and is relatively easy to dehull with few broken groats. The Oat Milling Industry has expressed interest in the possible production of Mn02234 in western Canada, a first in recent memory for a Minnesota line. In addition to Mn02234, we also have eight other advanced lines being purified and/or increased for possible future release. Except for one of these, there are less data available because of less history in the program. This summer, a second major effort has been launched to produce a much more genetically diverse base of crown rust resistance with the goal of more durable resistance. Forty lines from diverse origins were included in this past fall's greenhouse crossing block after evaluation at three eastern Canadian field locations, St. Paul campus fields, and in the field in Parana, Argentina. These lines were also evaluated as seedlings by inoculation with individual Midwestern United States field crown-rust isolates collected in summer 2005. The latter data were analyzed to determine the level of contrast/similarity of the reactions among the pairs of potential combinations and those combinations with the most contrasting reactions were emphasized. A total of 640 F1 seeds from 89 crosses involving 35 parents was produced. The thesis research of M. Gaggero indicted that BYDV scores of naturally infected oat plants in St. Paul, Minn. did not correlate well with artificially inoculated ones in Urbana, Ill. There were differences among crosses between closely related parents and there was some suggestion of material effects when Sesqui was a parent. In general, heritability estimates for BYDV scores were low. Further, previously reported AFLP markers for BYDV tolerance could not be validated, but two new markers associated with BYDV reaction were detected.

IMPACT: 2006/01 TO 2006/12
With the anticipated release of Mn02234 in 2008, we will have achieved an intended broadening of primary breeding objectives beyond grain yield by successfully including several grain quality factors, both compositionally and physical, plus some much needed, more durable crown rust resistance.

PUBLICATIONS (not previously reported): 2006/01 TO 2006/12
1. Stuthman, D.D., K.J. Leonard, J. Miller-Garvin. 2007. Breeding Crops for Durable Resistances. In: Advances in Agronomy. D.L. Sparks (ed.) Submitted December 1, 2006, as invited major review.
2. Stuthman, D.D. and J.J. Jannink. 2006. Alternatives to Single Major Gene Crown Rust Resistance. American Oat Workers Conference Proceedings July 23 - 26, Fargo, ND. http://wheat.pw.usda.gov/ggpages/oatnewsletter/v50/AOWC/
3. Gaggero, M. 2006. Early Generation and Molecular Assisted Selection for Barley Yellow Dwarf Virus Tolerance in Elite Oat Populations. M.S. Thesis. University of Minnesota, St. Paul.

PROJECT CONTACT:

Name: Stuthman, D. D.
Phone: 612-625-3709
Fax: 612-625-1268
Email: stuth001@umn.edu
URL: http://www.agro.agri.umn.edu/faculty/dds.htm