PAG-II Plant Genome II Conference

Town & Country Conference Center, San Diego, CA, January, 1994.


PG-II: MOLECULAR MAPPING OF GRAIN QUALITY TRAITS IN WHEAT

MOLECULAR MAPPING OF GRAIN QUALITY TRAITS IN WHEAT.

James A. Anderson 1, Mark E. Sorrells 2, Patrick L. Finney 3, and Steven D. Tanksley 2, 1 Crop and Weed Sciences Department, North Dakota State University, Fargo, ND 58105, 2 Department of Plant Breeding and Biometry, Cornell University, Ithaca, NY, 3 USDA-ARS Soft Wheat Quality Laboratory, Wooster, OH.


The selection of wheat (Triticum aestivum L.) lines with high grain quality is difficult because of a lack of knowledge of its genetic control and the effects of environment and genotype x environment interaction. Breeding progress would be enhanced by the use of selection criteria that can explain a large portion of the genetic variation in grain quality and can be used economically to screen early generation materials. DNA markers linked to loci controlling these traits could be the basis of such a diagnostic assay. Our objective was to investigate the genetics of several grain quality traits in wheat and map them using DNA markers. A population of 78 recombinant inbred (RI) lines derived from the cross of the soft white wheat NY6432-18 and the hard white wheat 'Clark's Cream' was evaluated for preharvest sprouting (PHS) in eleven environments and four other grain quality traits in two environments. Fifty-nine RFLP markers have been mapped in this population. Associations between grain quality traits and RFLP markers were determined by one-way analysis of variance and regression. The variation among RI lines was highly significant for all grain quality traits. Multiple regression models constructed from significant RFLP markers explain the following percentage of the phenotypic variance: PHS, 35%; Flour Protein Concentration, 40%; Alkaline Water Retention Capacity, 28%; Adjusted Flour Yield, 14%; and Kernel Hardness, 9%. Epistatic interactions between significant markers were found for PHS and flour protein concentration. We continue to map additional polymorphisms in this population to identify other genetic factors conditioning grain quality.


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