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Genetic engineering is becoming a useful tool in the improvement of plants and plant-based raw materials. Varieties with value-added traits are developed for nonfood use in industrial and medical production, and different production lines must be kept separate. For good management practices, knowledge of relevant gene flow parameters is required. In the present study, pollen-mediated dispersal of transgenes via cross-fertilization was examined. A transgenic barley (Hordeum vulgare L.) line carrying a marker gene coding for neomycin phosphotransferase II (nptII) was used as a pollen donor. For maximum resolution, a cytoplasmically male-sterile barley line was utilized as recipient and the flow of nptII transgene was monitored at distances of 1, 2, 3, 6, 12, 25, 50, and 100 m from the donor plots of 225 and 2000 m(2). Male-fertile plots at a distance of 1 m were included to measure the transgene flow in normal barley. The number of seeds obtained from male-sterile heads diminished rapidly with distance and only a few seeds were found at distances of 50 and 100 m. Molecular genetic analysis (polymerase chain reaction-PCR) revealed that all seeds obtained from male-sterile heads at a distance of 1 m were transgenic, as anticipated. However, only 3% of the distant seeds (50 m) actually carried the transgene, whereas most of them resulted from fertilization with nontransgenic background pollen. This background pollen was mainly due to pollen leakage in some male-sterile heads. In normal male-fertile barley, the cross-fertilization frequency with transgenic pollen varied from 0 to 7% at a distance of 1 m, depending on weather conditions on the heading day. We conclude that, because of competing self-produced and nontransgenic background pollen, the possibility of cross-pollination is very low between a transgenic barley field and an adjacent field cultivated with normal barley. However, adequate isolation distances and best management practices are needed for cultivation of transgenic barley.

The processing quality of cereals can be modified by altering the structural grain constituents or the enzyme activities that mobilize storage reserves of the seeds. In order to complement the malt enzyme spectrum, a gene encoding for a thermotolerant fungal endo-(1,4)-ß-glucanase was introduced into two barley cultivars, Kymppi and Golden Promise. The gene was expressed in the seeds during germination, thus providing a thermotolerant enzyme that is active under mashing conditions. The amount of thermotolerant ß-glucanase produced by the seeds (ca. 0.025% soluble seed protein) has been shown to be sufficient to reduce wort viscosity by decreasing the soluble ß-glucan content. For the safe commercial cultivation of transgenic plants risk assessment of their cultivation is needed. In our study experimental estimates of the transgene flow from transgenic barley by pollen dispersal were produced. Field trials were conducted during the summers of 1996 and 1997. A transgenic barley line homozygous for the gene encoding for neomycin phosphotransferase was used as a source of pollen and male-sterile barley lines as recipients. In order to be able to transform the cross-fertilization frequencies to corresponding values of normal male-fertile barley, plots of normal barley were also included in the experimental plan. On the basis of our study, cross-fertilization in male-sterile recipient barley is possible with very low frequency up to 50 meters from the donor area. However, the frequency dramatically decreases with distance and due to self-pollination the possibility of cross-fertilization remains very low in normal cultivated barley.

The objective of this study was to evaluate the effect of D, C, and B hordein polypeptides on malting quality of 19 spring barley (Hordeum vulgare L.) cultivars. Results from the study indicated that B hordein polypeptide combinations had some effect on malting quality through regulating diastatic power. Comparison of the relative amounts of hordein extracted in the presence and absence of reducing agent was made to determine the effect of disulphide bonds on malting quality. In the absence of reducing agent in the extraction solvent, a high concentration of B hordein was correlated with an increase in extract yield. Conversely, in the presence of reducing agent, an increase in B hordein concentration increased the Kolbach Index. A higher D hordein to B hordein ratio, when the former contained a high concentration of disulphide bonds, decreased malting quality to a greater extent than when fewer disulphide bonds were present. When environmental conditions favoured high N uptake efficiency, a larger proportion of D hordein disulphide bonds was synthesized, leading to decreased malting quality. It is speculated that cultivars with lower grain N yield and a lower D:B ratio yield good quality malt.

Transgenic barley plants (Hordeum vulgare L. cv. Kymppi) were obtained by particle bombardment of various tissues. Immature embryos and microspore-derived cultures were bombarded with gold particles coated with plasmid DNA carrying the gene coding for neomycin phosphotransferase II (NPTII), together with plasmid DNA containing the gene for β-glucuronidase (GUS).

Transgenic barley plants (Hordeum vulgare L. cv. Kymppi) were obtained by particle bombardment of various tissues. Immature embryos and microspore-derived cultures were bombarded with gold particles coated with plasmid DNA carrying the gene coding for neomycin phosphotransferase II (NPTII), together with plasmid DNA containing the gene for β-glucuronidase (GUS).Bombarded immature embryos were grown to plants without selection and NPTII activity was screened in small plantlets. One plant proved to be transgenic (T0). This chimeric plant passed the transferred nptII gene to its T1 progeny. The presence of the nptII gene was demonstrated by the PCR technique and enzyme activity was analyzed by an NPTII gel assay. Four T0 spikes and 15 T1 offspring were transgenic. The integration and inheritance was confirmed by Southern blot hybridization. Transgenic T2 and T3 plants were produced by isolating embryos from green grains of transgenic T1 and T2 plants, respectively and growing them to plants. After selfing, the ratio of transgenic to non-transgenic T2 offspring was shown to follow the rule of Mendelian inheritance. The general performance of transgenic plants was normal and no reduction in fertility was observed.Microspore-derived cultures were bombarded one and four weeks after microspore isolation. After bombardment, cultures were grown either with or without antibiotic selection (geneticin R or kanamycin). When cultures were grown without selection and regenerated plants were transferred to kanamycin selection in rooting phase, one out of a total of about 1500 plants survived. This plant both carried and expressed the transferred nptII gene. The integration was confirmed by Southern blot hybridization. This plant was not fertile.