Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/1994
Publication Date: N/A
Interpretive Summary: The development of laboratory methods to genetically alter plants promises to produce plants with unique and useful characteristics that cannot be created efficiently by conventional methods of hybridization. However, to utilize these techniques for barley, individual barley cells must be grown and coaxed into forming barley plants. This process, called plant regeneration, may create unwanted mutations (called somaclonal variation) that reduce the health of the regenerated plants and make them unsuitable for commercial agriculture. This study was designed to find out if soma- clonal variation occurred in regenerated barley plants by measuring the performance of 174 barley lines derived from regenerated barley plants of 6 commercial varieties. The results indicated that most regenerated barley plants possessed undesirable somaclonal variation that led to reductions in grain yield and grain quality. However, certain plants of some of the varieties performed as well as plants that had never been grown under laboratory conditions. The conclusions of this study were that laboratory producted mutations--somaclonal variation--occur and that their occurrence must be taken into consideration when utilizing laboratory methods to genetically improve barley.
Technical Abstract: Current methods for the production of genetic variability in vitro expose cultured cells to a potentially mutagenic environment. Selected genetic variability produced by in vitro selection or genetic transformation will be most useful if such variability is not accompanied by unselected and undesirable mutations. To determine the potential for recovering genotypes snot altered by passage through tissue culture, 30 families of tissue culture-derived lines from six barley cultivars were analyzed for agronomic performance. Each family was derived from a single regenerated plant that in turn derived from an immature embryo callus culture. Four to six R2 plants were selected from each family based on phenotypic similarity to the uncultured parental controls. One hundred seventy four R2-derived lines were advanced by bulking to the R4 and R5 generations for replicated testing. The results indicated that the agronomic performance of the majority of these lines was altered by passage through tissue culture, and that the alterations were generally undesirable. Genotypic differences were noted in the frequency and degree of agronomic alterations. Families within genotypes was an important source of variation, but selections within families was not. Successful selection of tissue culture-derived barley lines without somaclonal variation therefore may be genotype- dependent, and may require screening large populations of regenerated plants.