Gluten index compared with SDS-sedimentation volume for early generation selection for gluten strength in durum wheat

Clarke, F. R., Clarke, J. M., Ames, N. A., Knox, R. E. and Ross, J. R. 2010. Gluten index compared with SDS-sedimentation volume for early generation selection for gluten strength in durum wheat. Call. J. Plant Sci. 90: 1-11. Gluten strength is an important end-use quality factor in durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.], affecting pasta manufacture and cooking quality. The objective of this research was to determine the inheritance and heritability of gluten index in comparison with the widely used SDS-sedimentation (sodium dodecyl sulphate) technique for selection for gluten strength. Seven durum populations were grown in replicated, multi-location, multi-year field trials in Saskatchewan, Canada, during the period 1995 to 2002. Gluten index and SDS-sedimentation volume were determined on all plots after harvest. Both traits were affected by genotype, and to a lesser extent by year or location. Genotype environmental interactions were generally minor. The majority of genotypes in each population had similar relative ranking for gluten index and SDS-sedimentation volume in each environment. Both traits were highly heritable, ranging from 0.80 to 0.97, and both were complexly inherited with estimates of effective factors ranging from 3 to 21. Gluten index and SDS-sedimentation volume were highly correlated, indicating that they are measuring similar aspects of gluten strength. SIDS-sedimentation volume was positively associated with protein concentration (r(2)=0.52), but gluten index was not. Therefore, gluten index would be more desirable than SDS-sedimentation Volume for use in selection where there are within-trial protein concentration trends.