Featuring the Oregon Wolfe Barley Linkage mapping of single genes determining notable phenotypes of economic value Featuring the Oregon Wolfe Barley nud kap lks2

A quick review of doubled haploids Gametes (male or female) Nud nud (n = 7) F1 = Nud nud (2n = 2x = 14) Induction/regeneration Nud nud Mature plants/grain Haploid plantlets (n = 7) Nud Nud nud nud (2n = 2x = 14) Chromosome doubling (spontaneous/induced)

Hordeum bulbosum DH production in barley Emasculate H. vulgare H. bulbosum pollen The Hordeum bulbosum method to produce doubled haploid barley. P. Devaux: Florimond Desprez, Biotechnology Laboratory, P.O. Box 41, 59242 Cappelle en Pevel,e, France. pierre.devaux@florimond-desprez.fr Pollinate H. vulgare with H. bulbosum Leave ~ 10 days for embryo to develop

Hordeum bulbosum DH production Tissue culture developing embryos Colchicine Produce seed Breeding/genetics forever The Hordeum bulbosum method to produce doubled haploid barley. P. Devaux: Florimond Desprez, Biotechnology Laboratory, P.O. Box 41, 59242 Cappelle en Pevel,e, France. pierre.devaux@florimond-desprez.fr

Anther Culture DH production in barley Harvest donor spikes Apply stress conditions Place anthers on induction medium Sub-culturing for shoots and roots Spontaneous doubling Produce seed Breeding/genetics forever

OWB dominant x OWB recessive F1 Doubled haploids

Heart disease, high cholesterol, obesity Eating barley can help address these challenges - soluble dietary fiber But who wants to eat hulls? - insoluble dietary fiber Options for no hulls Pearling Naked barley

Score the phenotype with samples provided and add to the linkage map Hulled and naked (hulless) Let’s map the gene! Score the phenotype with samples provided and add to the linkage map Taketa, S. et al. 2008. PNAS 105:4062-4067

Hooded varieties are better for forage than awned varieties Awns are painful to livestock (and humans)

Hooded and awned Let’s map the gene! Score the phenotype with samples provided (or online images) and add to the linkage map Muller et al. Nature. 1995: 374: 727-730 McCoy, S.B. 2000. OSU scholars archive

Nud maps fine (expected segregation and map location) But what is going on with Kap? Not expected segregation Not expected map location Don’t look at the next slides until you’ve been through the two readings on Kap Develop your own strategies to map Kap, based on the readings. Now go to the next slides.

A summary of the epistatic interaction The Kap locus: Kap_ confers the hooded phenotype; kapkap = short-awned. The LKs2 locus: Lks2_ confers long awn phenotype; lks2lks2 the short awn phenotype BUT Kap and LKs2 interact: the long awn phenotype is not visible when the dominant allele is present at the Kap locus. KKLL = hooded (no awns) KKll = short awns (no hoods) kkLL = long-awned (no hoods) kkll = short awns (no hoods)

Moving ahead with mapping Based on the epistatic model, Lks2 can be mapped (although there are complications deciding how long is long and how short is short) because you can impute that all hooded types are LL, that all long-awned types are kkLL and that all short-awned types are ll. Kap, however, is still problematic. KKll and kkll genotypes cannot be distinguished based on phenotype. What about based on genotype? hvnox3 is in the map data set: based on the allele scores provided, each of the OWB lines can be assigned a Kap or a kap allele type. Now you can assign genotypes to each OWB DH at the two loci.