Molecular Markers Associated with Differences in Bread-making Quality in a Cross Between Bread Wheat Cultivars with the Same High Mr Glutenins

Journal rif Cereal Science 27 Molecular Markers Associated with Differences in Bread-making Quality in a Cross Between Bread Wheat Cultivars with the Same High Mr Glutenins M. M. Manifesto*, S. Feingold*, H. E. Hopp*, A. R. Sc;:hlattert and J. Dubcoysky+ *Instituto de Biotecnologla ClCV-INTA and t/nstituto de Recursos Biol6gicos ClRN-INTA, 1712 Castelar, Buenos Aires, Argentino, =tDeportment of Agronomy and Range Science, University of California, Davis, CA, 95616, US.A Received 10 April 1997 ABSTRACT The association between molecular markers and bread-making quality (BMQ) was investigated in a cross between two wheat cultivars with the same high J,1,-glutenin subunits but significantly different BMQ A segregant F1 population was generated after crossing Klein 32 and Chinese Spring, and the BMQ of each F1-derived F3 family was estimated using sodium dodecyl sulfate (SDS) sedimentation and mixograms. The same families were characterized for II polymorphic loci using restriction fragment length polymorph isms (RFLP) and single sequence repeats (SSR). These loci were specifically selected for their complete or close linkage to storage protein gene families. No significant differences in BMQ were detected at XClu-Bl and XClu-Alloci using RFLP markers. Highly significant (P<0'01) differences in all BMQparameters were detected for XCli-Bl and XClu-B310ci on chromosome arm I BS. The increase in the number of Klein 32 alleles at these loci determined a linear increase in sedimentation and mixogram values. It was not possible to differentiate the effect of XClil from that of XClu3 because of the close linkage between these two loci. These two loci, considered together, explained from II to 15% of the ~ariation in BMQ observed in this cross. The inclusion of the protein content of each sample as a covariable in the model increased thr proportion of variation in SDS sedimentation explained by the analysis up to 46'Yo and the precision of the statistic analysis up to 180%. Mixing paramrters showed a lowrr correlation with protein content than SDS sedimentation parameters, and the increase in precision obtained by the use of the protein content as a covariab1e was non-significant. © 1998 Academic Press Limill'd keywords: wheat, breadmaking quality, low molecular weight glutenins, gliadins, SSR, RFLP. INTRODUCTION ABBREVIATIONS USED: ANOY A = analysis of variance; ANCOYA = analysis of covariance; BMQ = bread- making quality; CIMMYT = Centro Internacional de Mejoramiento de Maiz y Trigo; HMr-GS = high rel- ative mobility glutenin subunits; LMr-GS = low relative mobility glutenin subunits; RFLP = restriction fragment length polymorph isms; SDS-PAGE=sodium dodecyl sulfate~polyacrylamide gel electrophoresis; SSR = single sequence repeats. Correspondin,f!, author:]. Dubcovslry. 0733 5210/981030217 + II $25.00/0/jc970 168 The quantity and composition of seed storage proteins affect bread-making quality (BMQ). The quantity of protein in the grain is mainly affected by differences in growing conditions, particularly the availability of nitrogen. A reduction in the level of protein in the seed of a cultivar is often associated with a decrease in BMQindependently of the protein composition I. However, for a given protein content the composition of seed storage © 1998 Academic Press Limited