Combining Ability for Tolerance to Pre-Harvest Sprouting in Common Wheat (Triticum aestivum L.)

Pre-harvest sprouting (PHS) affects wheat (Triticum aestivum L.) yield and end-use product quality leading to massive economic losses. Red wheat cultivars are typically more resistant to PHS than white wheat. The objective of this study was to identify red wheat genotypes capable of donating genes for PHS tolerance to white wheat, independent of red seed coat color. A factorial (M x N) mating was conducted using six white wheat genotypes 'Cayuga', 'Nuplains', NW97S218, NW99L7068, 'Peck', and 'RioBlanco' and eight hard red wheat genotypes 'Arapahoe', CO960293-2, 'Jagalene', NE98466, NI01812, 'Wesley', 'Niobrara', and 'Plainsman V'. General combining ability (GCA) for individual parents and specific combining ability (SCA) for specific crosses were used to identify effective red wheat donors. General combining ability and SCA were calculated from a pre-harvest tolerance score (Lambda) determined after testing heads in a misting chamber and from falling number measurements of field-grown materials. General combining ability among red parents was significant for both Delta and falling number, but not in white parents. General combining ability or SCA by environmental interactions, with the exception of. from GCA in red wheat, were significant. Jagalene and Niobrara were identified as red wheat genetic reservoirs for additional genes of PHS tolerance useful in white wheat breeding. A significant correlation of SCA of falling number and SCA of Delta was detected (r = 0. 38, n = 48, P = 0.007). The falling number assay can be replaced by an assay for Delta to evaluate PHS tolerance in wheat breeding programs in areas in which pre-harvest sprouting is not routinely observed.