Identification of markers linked to genes for sprouting tolerance (independent of grain color) in hard white winter wheat (HWWW)

Key message Hard red wheats can donate genes to hard white wheats for tolerance to preharvest sprouting, the effects are quantitative in nature, and may be tracked with previously described DNA markers. Abstract Pre-harvest sprouting (PHS) of wheat (Triticum aestivum L.) can negatively impact end-use quality and seed viability at planting. Due to preferences for white over red wheat in international markets, white wheat with PHS tolerance has become increasingly desired for worldwide wheat production. In general, however, red wheat is more tolerant of sprouting than white wheat. The main objective of this study was the identification of PHS tolerance conditioned by genes donated from hard red winter wheat, using markers applicable to the Great Plains hard white wheat gene pool. Three red wheat by white wheat populations, Niobrara/NW99L7068, NE98466/NW99L7068 and Jagalene/ NW99L7068 were developed, and white-seeded progenies were analyzed for PHS tolerance and used to identify markers for the trait. In the three populations, marker loci with significant allelic effects were most commonly located on chromosomes of group 2, 3, 4 and 5, though additional markers were detected across the wheat genome. Chromosome 3A was the only chromosome with significant markers in all three populations. Markers were inconsistent across the three populations, and markers linked to tolerance-inducing loci were identified in both tolerant and susceptible parents. Additive effects of marker loci were common. In the present investigation, a wide range of PHS tolerance was observed, even though all lines were fixed for the recently reported positive TaPHS1 allele. PHS tolerance is controlled by additive major gene effects with minor gene effects where variations of minor gene effects were still unclear

Potential of red wheats to donate genes influencing pre-harvest sprouting of white wheats, independent of grain color

In wheat (Triticum aestivum) global production, pre-harvest sprouting (PHS) plays an important role for all processes including end-use quality. Rain and high humidity encourages PHS in the field. The U.S. domestic and export markets presently have high demand for white wheats, which tend to be more susceptible to PHS than red wheats. To allow the U.S. to reliably export white wheats to world markets, PHS tolerance will be essential. The first objective of this study was to identify red wheats capable of donating genes for PHS tolerance in white wheats, independent of red seed color. A factorial (M × N) mating was conducted using eight red wheats: ‘Niobrara’, ‘Wesley’, ‘Arapahoe’, NE98466, CO960293-2, ‘Jagalene’ NI01812 and ‘Plainsman V’ and six white wheats: ‘Nuplains’, NW99L7068, ‘RioBlanco’, ‘Cayuga’, NW97S218, and ‘Peck’. General combining ability (GCA) for individual parents and specific combining ability (SCA) for specific crosses was used to identify effective donor red wheat parents. GCA and SCA were calculated from a pre-harvest tolerance score (Delta Value) determined in a misting chamber, and from Falling Number measurements of field-grown materials. Jagalene and Niobrara were identified as potential red wheat genetic reservoirs for additional genes of PHS tolerance. Identification of PHS tolerance conditioned by genes donated from hard red winter wheat, using markers applicable to the Great Plains hard white wheat gene pool was the second objective. Three populations, Niobrara/NW99L7068, NE98466/NW99L7068 and Jagalene/NW99L7068, were developed and white-seeded progeny analyzed for PHS tolerance and used to identify markers for the trait. Single gene models showed significant effects due to marker genotype at P\u3c 0.10 in the following cases; three markers in Niobrara/NW99L7068, possibly located on chromosomes 2B, 3A, 3B, 4B, 5A, or 7B; five markers in NE98466/NW99L7068 possibly located on chromosomes 2B, 2D, 3A, 5A, 5B, 6B, 6D, 7A and 7D; five markers in Jagalene/NW99L7068 on chromosomes 1D, 2D, 3A, 5B and 5D. In the two gene models, mean Delta Value scores of all TT classes (two putative PHS tolerant loci) were lower, and, hence, PHS tolerance was higher, than the SS classes (two putative susceptible loci), which is an advantage for improving PHS tolerant lines