|Halbert, Susan - UNIVERSITY OF IDAHO|
|Lemaux, Peggy - UNIVERSITY OF CALIFORNIA|
Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 31, 1997
Publication Date: N/A
Interpretive Summary: Genetic engineering techniques hold great promise for increasing the yield, quality, and usefulness of agricultural commodities such as barley. Examples of potential uses of genetically engineered barley include the introduction of genes for improved malting quality, improved insect and disease resistance, and increased nutritional value. Such improvements are eexpected to increase the profitability of barley growers and processors, decrease the cost to consumers, and improve the environment by reducing dependence on synthetic chemicals. For this technology to be successful and efficient, two conditions must be met. First, useful genes must be introduced into a plant. This can be done with barley. Second, the techniques used to introduce the genes into the plant must not harm the plant, or mutate it. In our study, we examined the ability of genetically engineered barley to grow normally in the field. We compared this barley to regular, or non-genetically engineered barley. We found that the genetically engineered barley was harmed by the process used to introduce the genes. The plants did not yield as much grain, or as good a quality grain, as the regular barley. This would probably prevent these plants from being efficiently used by farmers, and plant breeders could have problems using them in hybridization programs. Therefore, we believe that the genetic engineering techniques for barley plants must be improved so that genetic engineering is less harmful to them.
Technical Abstract: Somaclonal variation (SCV) in transgenic plants may slow the incorporation of introduced genes into commercially competitive cultivars. Somaclonal variation in transgenic barley (Hordeum vulgare L.) was assessed in one experiment by comparing agronomic characteristics of 44 segregating transgenic lines in the T2 generation to their non-transformed parent ('Golden Promise'). A second experiment examined the agronomic characteristics of seven transgenic-derived, null (non-transgenic) segregant lines in the T2 and T4 generations. Compared to their uncultured parent Golden Promise, most of these lines were shorter, lower yielding, and had smaller seed, and the variability among individual plants was higher. The frequency and severity of the observed SCV was unexpectedly high, and the transformation procedure appeared to induce greater SCV than tissue culture in the absence of transformation. Attempts to understand the sources of SCV, and to modify transformation procedures to reduce the generation of SCV, should be made. KEY WORDS: Barley (Hordeum vulgare L.), agronomic performance, somaclonal variation, transgenic plants, progeny.