Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/1995
Publication Date: N/A
Interpretive Summary: The development of new varieties of barley for use by the malting and brewing industry is complicated by the precise standards for grain quality that must be met. In addition to meeting quality standards, new malting barley varieties must also be able to be grown profitably by the barley producers. Thus, breeding techniques that can make small, stepwise improvements in either quality or production characteristics to currently used varieties are desirable. Techniques such as genetic transformation theoretically can be used to make these small, stepwise changes through the introduction of single, specific genes. However, genetic transformation of barley currently requires that barley cells be grown in tissue culture, and these cells must at some point be induced to form plants. This process may generate changes in many characteristics; thus, such changes could prevent or impair the ability of breeders to change single traits by using genetic engineering. Practically, the actual consequence of such changes will depend on how many traits are affected, and how severely the traits are changed. The research in this report was conducted to determine whether or not tissue culture causes variation in barley, to determine the effect of this variation in malting quality, and to determine how severe the consequences of such variation might be.
Technical Abstract: The occurrence of somaclonal (tissue culture-derived) variation in plants regenerated from tissue culture will influence the efficiency with which techniques such as genetic transformation can be used in the development of new barley cultivars. To assess the affect of somaclonal variation on malting quality, twelve families of tissue culture-derived lines from three barley cultivars were analyzed using standard micromalting techniques. Each family was derived from a single regenerated plant that, in turn, was derived from an immature embryo callus culture. Five to six plants from each family were selected in the R2 generation based on phenotypic similarity to their uncultured parental controls, and advanced to the R4 and R5 generations for replicated field tests. The malting quality of the majority of these lines was altered by passage through tissue culture, and most alterations were undesirable. These results suggest that efforts should be made to delineate in vitro (tissue culture) conditions that are less mutagenic to cultured barley cells.