Agronomic Performance of Barley Lines Derived from Tissue Culture

The practical application of in vitro genetic manipulations to plant breeding may be hindered by unselected and potentially undesirable somacional variation. To determine the potential for recovering cultivars from tissue cultures without somaclonai variation, 30 families of tissue culture derived lines from six barley (Hordeum vulgare L.) cultivars were analyzed for agronomic performance. Each family was derived from a single regenerated plant that in turn was derived from an immature embryo callus culture. Four tosix 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 R5 generation. The results of replicated field trials indicated that the agronomic performance for the majority of these lines was altered by passage through tissue culture and that the alterations were generally undesirable. Cultivar‐dependent differences were noted in the frequency and degree of agronomic alterations. Families within cultivars was an important source of variation, but selections within families was not. Successful selection of tissue culture derived barley lines without somocional variation therefore may be cultivar dependent and may require screening large populations of regenerated plants.