Presentation on theme: "Increasing grain yield and improving BYDV tolerance in oat: Past, Present and Future Frederic L. Kolb 1 and Jean-Luc Jannink 2 1 Dep. of Crop Sci., Univ."— Presentation transcript:
Increasing grain yield and improving BYDV tolerance in oat: Past, Present and Future Frederic L. Kolb 1 and Jean-Luc Jannink 2 1 Dep. of Crop Sci., Univ. of Illinois, 2 USDA-ARS, Cornell Univ.
Outline Discuss breeding for increased yield and BYDV tolerance using the Univ. of Illinois program as an example Discuss trends in yield and BYDV tolerance from the UOPN
Outline Discuss a snapshot of germplasm exchange in North American oat on the basis of pedigree relatedness analysis Initiate discussion of changes to the UOPN to focus germplasm exchange using marker information Can oat breeding gains compete with other crops?
Introduction Grain yield and BYDV tolerance are important quantitatively inherited traits in oat Important breeding objectives
Barley Yellow Dwarf (BYD) Most important viral disease of oat Causes economically significant yield losses worldwide Host plant resistance is the best method for control of BYD
Barley yellow dwarf viruses (BYDVs) Five or more species have been described Phloem-restricted viruses Vectored by aphids Wide range of host species Symptoms - leaf chlorosis and reddening, stunting, blasting, and reduced root growth
Blasting due to BYDV
Reduced root growth due to BYDV
Trends in BYDV tolerance of breeding lines in Uniform Nurseries
Progress in BYDV tolerance (1966 – 2007) UEOPN ~ 5.4 to 5.0 UMOPN~ 6.2 to 4.6 Best lines tended to be in the 2-3 range The average number of IL lines in the top five for BYDV tolerance: 2.5 for UEOPN and 2.2 for UMOPN.
2008 UMOPN Plots – Urbana, IL Clintland 64 – BYDV susceptibleIL BYDV tolerant breeding line
University of Illinois procedures for evaluation of BYDV tolerance Two or three replications of hills planted with 15 seeds / hill Inoculated with aphids carrying BYDV-PAV at Feekes GS 2 Symptoms rated at Feekes 10.6 Rating based on chlorosis, stunting, and blasting Scale 0 = no symptoms, 9 = severe
Collecting Aphids from cultures
BYDV Evaluation Hills
Selection for BYDV Tolerance Selection to date has relied on phenotypic evaluation. Molecular markers tried but the small number of markers has been a problem. The availability of DArT markers and association mapping hold promise for the future.
Essentially a long-term open recurrent selection breeding program with selection for elite lines embedded within each cycle. University of Illinois Breeding Procedures
“North American oat breeding is a big recurrent selection program with slow mixing: a communal effort.” - Brian Rossnagel
Use modified single seed descent to advance generations rapidly in the greenhouse and cycle new parents into the program quickly. Cross (Feb ’08) to selection of panicles from F 4 bulks in ~ 18 months (July ’09) University of Illinois Breeding Procedures
Trends in Yield of Breeding Lines in Uniform Nurseries
Average Yields of Uniform Nurseries (1966 – 2007) UEOPN ~ 62 bu/A to 118 bu/A = ~ 2222 kg/ha to 4229 kg/ha - Increase of 1.3 bu/A/yr (48 kg/ha/yr) UMOPN ~ 70 bu/A to 119 bu/A = ~ 2509 kg/ha to 4265 kg/ha - Increase of 1.2 bu/A/yr (43 kg/ha/yr)
Objectives of the Uniform Oat Performance Nurseries Test lines for broader adaptation Friendly competition! Who’s line will be the best in 2008? Identify lines from other programs with potential value as parents in my program
Moving from exchange of genotypes to exchange of “genomic regions” Uniform nurseries have provided an important mechanism for oat breeders to exchange genotypes. With high density markers and association mapping it may be possible to refine the exchange to introgression of “genomic regions that perform well locally.”
Pedigree Relatedness Pedigrees are more difficult to curate than marker data => Relatedness in what follows is based on marker data from the new DArT resource
Relatedness between Programs
Saskatchewan and Minnesota CDC Sol-Fi CDC ProFi Sesqui Leonard Wabasha & a sib line
Winnipeg and Indiana Still not completely unrelated!
Value of “exotic” genomic regions Lines from other programs will often be poorly adapted in your target environments However, poorly adapted germplasm often carries favorable alleles –Tanksley, S.D. et al Advanced backcross QTL analysis … Theor. Appl. Genet. 92:
Identification Requirements “External genomic regions performing well locally” Segregating in the elite UOPN germplasm Evaluated locally in your own target environments UOPN lines genotyped at high density
Modifications to the UOPN In the near future UOPN entries could be genotyped at relatively high density for a modest fee per entry (~ $50 ) What modifications in the phenotyping and line purification could leverage the most out of this new data?
Can oat breeding gains compete with other crops? The short answer – NO. Why? –Resources for research on a species impact the rate of progress. –Oat is at a huge disadvantage. Maize – C4 metabolism and multibillion dollar industry
Summary We have made progress! – Varieties with excellent tolerance to BYDV and enhanced yield potential have been developed. New tools including DArT markers, additional SSR markers, and association mapping hold promise for enhancing selection in the future.
Acknowledgments Quaker Foods and Beverages: A Division of Pepisco USDA-ARS The University of Illinois USDA-NRI-CSREES Grant Personnel: Norman Smith Eric Brucker