Influence of screening directions and puroindoline alleles on the heritability of small-scale bread-quality tests

Abstract

Important methods applied for the breeding of bread-quality wheat (Triticum æstivum L.) consist of small-scale bread-quality tests for the determination of the grain protein content, SDS-sedimentation volume and single-kernel characterization system (SKCS) grain hardness. The effect of the screening direction (upward vs. downward) and puroindoline alleles on the heritability of small-scale breadquality was investigated for the "Hokushin/KS 831957//Kitami 72/Satsukei 226" (Pinb-D1a/D1b//D1a/D1b), and "Tohoku 195/Satsukei 226//Kitami 72/KS 831957" (Pinb-D1b/D1b//D1a/D1b) lines and F3 and F4 populations derived from them. The SKCS hardness and SDS-sedimentation volume showed a relatively higher heritability (0.71-0.89), whereas the grain protein content showed a lower heritability (0.27-0.38). The SDS-sedimentation volume showed a higher heritability in downward screening (0.88-0.91) than in upward screening (0.66-0.67), while SKCS hardness showed a similar heritability in both directions. Although the SKCS hardness, and the grain protein content showed a higher heritability when Pinb-D1a/D1b//D1a/D1b was crossed, the heritability of the SDS-sedimentation volume was not affected. Overall, screening for the SDS-sedimentation volume was found to be useful for eliminating low-grade bread-quality lines, regardless of the puroindoline alleles. Efficient bread-quality wheat breeding could thus be achieved by concurrent screening for SDS-sedimentation volume and SKCS hardness, due to the higher heritability and relatively lower correlation coefficient of these parameters.