[en] Swedish research on induced mutations was initiated on a small scale at Svaloef in 1928 by H. Nilsson-Ehle and A. Gustafsson. In 1953, at the instigation of the Swedish Government, the Group for Theoretical and Applied Mutation Research was established. Its aim was to study basic research problems to influence and improve the methods for breeding cultivated plants. Research activity peaked during the 1950s and 1960s, and has brought a wealth of observations of general biological importance. In barley, the main experimental material, about 10,000 different mutant genes, genetically and agronomically studied, have now been incorporated into the Nordic Gene Bank. Some exist in important barley varieties. Four mutant groups are discussed here: the eceriferum mutants, affecting the wax layer; mutants affecting the development of the lateral florets (hexastichon and intermedium); early mutants; and the group of mutants that provide resistance to barley powdery mildew. Useful mutations in barley include a wide range of economically important characters that influence the morphological as well as the physiological and biochemical properties. 45 refs, 2 tabs

[en] The semi-dwarf type in barley is very heterogeneous, reduced culm length being more or less characteristical of a number of different groups of mutants in barley at the side of the short culm mutants proper. Thus, short culm may occur associated with the mutant characters erectoides (short spikes), praematurum (early), globosum (rounded seeds), upright, and strawstiff. Covariation studies of 111 mutants in the five ert-loci ert-a, -b, -c, -d, and -e showed a positive correlation between culm length and yielding ability. The patterns of distribution differ among the loci; but favourable deviants of semi-dwarf type are indicated for all five loci. For the three main mat-loci mat-a, -b, and -c, no correlation between culm length and yielding ability was shown; mutants in mat-a generally had shorter culm length. Thus, mutants of the praematurum type compared with mutants of the erectoides type may offer more favourable materials for selecting high-yielding semi-dwarf types. Among the 52 short culm mutants, those with extreme reduction of culm length showed, without exception, strong reduction of yield. Among the 23 strawstiff mutants, on the other hand, the majority, even among the shortest ones, exceeded the average yield of the mother variety. In an M₂ material of cv Sv Frida, sodium azide compared with neutrons turned out to be clearly more efficient to produce short culm M₃ lines. In studies of mutations affecting the development of lateral florets in the three two-row cv Sv Bonus, Sv Foma, and Sv Kristina single mutants of intermedium type showed no effect on culm length and maintained the varietal differences. Double int mutants, irrespective of their being derived from cross combinations within a variety or between varieties showed a marked reduction of culm length. Triple mutants, with the additional contribution of a six-row gene from locus hex-v, showed an apparent increase in culm length. A special interaction between the six-row locus on one side and int-loci on the other side is made probable. (author). 4 refs, 4 tabs

[en] Three special cases of induced mutations in barley are discussed in this paper. They are denoted here as the Gunilla, the Pallas and the Mari cases, after the three named varieties to which the original mutants gave rise. The original mutants described represent just a small sample of the induced mutants, many of which have been tested in practice and have been further studied in basic genetics and evolutionary research. The three approved varieties have given rise to further recombination families, which also to some extent have been fused. Two of the mutant cases - Pallas and Mari - were directly useful in practice and officially approved. The third case involved a mutant of special appearance - a ''bushy type'' with an intense blue wax coating and with a supreme lodging resistance. The mutant was used in developing the Gunilla variety, which arose by recombination breeding. This variety has been highly satisfactory in further gene recombination work. A similar situation has prevailed with regard to the Pallas and Mari families arising after gene recombination, too. Up to now, the Gunilla, Pallas and Mari families include a long series of released and officially approved varieties. Several of them represent valuable agricultural contributions with wide areas of cultivation. These three mutants - with their recombination families - led to greatly increased straw stiffness and high grain production. Their phenotypic expression often corresponds to a dwarf or semidwarf description. One of the mutants - the Mari genotype - represents a group of genes and alleles which give rise to profound changes in the photoperiod (and partially also in the thermoperiod) behaviour. In fact, often even such small changes have a fundamental influence on adaptation and distribution. Data are presented analysing the property of lodging resistance with the background of plant, tiller and internode structure. A method of partial back-mutation was worked out in separating traits generally mutating together. The method adopted by D. von Wettstein for the analysis of erectoides mutations in barley was found to be appropriate in complicated cases of trait combinations. (author)

[en] Through parallel phytotron, greenhouse and field analyses 23 short-day tolerant early mutants of barley have been isolated from 59 greenhouse-tested genotypes and several hundred others cultivated under field conditions. One mutant, carrying the gene (allele) mat-a⁸, was released under the name of Svaloef's Mari. Later, after gene recombination, it gave rise to several valuable varieties. Mari and its derivative Mona, which also possesses the gene mat-a⁸, are adapted to widely different climatic constellations and produce very high yields under optimal conditions. Short-day tolerant mutants can easily be isolated and identified by simple greenhouse techniques. Most of such mutants belong to the locus mat-a. Different degrees of short-day tolerance exist. No certain case of a locus-b mutant being short-day tolerant was found. Previous conclusions to the contrary are incorrect. (author)

No abstract available

[en] In 1928, the Swedish geneticists Hermann Nilsson-Ehle and Ake Gustafsson initiated experiments with induced mutations using a diploid barley species. The experiments started with X-rays and UV-irradiations, soon the first chlorophyll mutations were obtained followed by the first viable 'Erectoides' mutations. Several other valuable mutants were isolated: high-yielding, early maturity, lodging resistance and with changed ecological conditions. The X-ray experiments were then expanded with different pre- and after treatments, and using other types of irradiation. Neutrons, positrons etc, were used and finally chemical mutagenes, starting with mustard gas and concluding with the inorganic sodium azide. This research brought a wealth of observations of general biological importance, high increased mutation frequencies, differences in the mutation spectrum and the ability to direct mutagenesis of specific genes. This Scandinavian mutation research was non-commercial although some mutants have become agronomically valuable. Its peaks of activities were during the fifties, sixties and seventies. Barley has been the main experimental material, but other species were also included in the program. About 10 000 different mutants with a broad variation were collected and several mutant characteristics have been analyzed in more detail genetically and with regard to mutagen specificity. Among these mutant groups most effort has been concentrated on the three following ones: (1) Early maturity mutants. At an early stage it was established that the time for early heading and maturity could easily be changed by mutagenesis. 9 different mat loci could be identified among the drastic type of earliness. One of these loci mat-a proved to be very striking, it is photo- and thermo-period insensitive. It causes a profound change in photoperiod reaction, making the mutant heading even in short days, and it became important for breeding. (2) Six-row and Intermedium mutants. Two-row barley can be mutated in a single step to six-row barley and this affects the development of the lateral spikelets. All 41 Swedish mutants have been localized to one single locus, hex-v. But two-row barley can also produce spike development intermediate between the two- and six-row state. 11 different int loci could be determined and were studied in more detail. (3) Mutants affecting surface waxes. The epicuticular wax coating has a very complex genetic architecture and affects the presence and type of waxes on three different organs (spike, leaf sheath and leaf blade). In total 1580 mutants have been localized to 79 different cer gene loci. Seven different types of mutagenic agents have been applied, and a great range of mutability was found. (author)

[en] In 1928, the Swedish geneticists H. Nilsson-Ehle and A. Gustafsson started on their suggestion experiments with induced mutations using a diploid barley species. The experiments started with X-rays and UV-irradiations, soon the first chlorophyll mutations were obtained followed by the first 'vital' mutations 'Erectoides.' Several other valuable mutants were considered: high-yielding, early maturity, lodging resistance and with changed ecological adaption. Soon the X-ray experiments expanded with different pre- and after-treatments, also using other types of irradiation, such as neutrons, positrons etc., and finally with chemical mutagens, starting with mustard gas and concluding with the inorganic sodium azide. The research brought a wealth of observations of general biological importance, high increased mutation frequencies, differences in the mutation spectrum and to direct mutagenesis for specific genes. This Scandinavian mutation research was non-commercial even if some mutants have become of some agronomic value. The peak of its activities was during the 1950s, 1960s and 1970s. Barley has been the main experimental material, but also other species were included in the programme. Over the years a rather large collection of morphological and physiological mutations (10,000 different mutant genes) with a broad variation were collected and several characters have been analyzed in more detail genetically and with regard to mutagen specificity. Most effort has been made on the Early maturity mutants, the Six-row (hexastichon) and Intermedium mutant group, the Surface wax coating : Eceriferum (Waxless) mutants, Dense spike mutants and others. (author)

[en] Biomass is suggested to supply an increasing amount of energy in Sweden. There have been several studies estimating the potential supply of biomass energy, including that of the Swedish Energy Commission in 1995. The Energy Commission based its estimates of biomass supply on five other analyses which presented a wide variation in estimated future supply, in large part due to differing assumptions regarding important factors. In this paper, these studies are assessed, and the estimated potential biomass energy supplies are discusses regarding prices, technical progress and energy policy. The supply of logging residues depends on the demand for wood products and is limited by ecological, technological, and economic restrictions. The supply of stemwood from early thinning for energy and of straw from cereal and oil seed production is mainly dependent upon economic considerations. One major factor for the supply of willow and reed canary grass is the size of arable land projected to be not needed for food and fodder production. Future supply of biomass energy depends on energy prices and technical progress, both of which are driven by energy policy priorities. Biomass energy has to compete with other energy sources as well as with alternative uses of biomass such as forest products and food production. Technical progress may decrease the costs of biomass energy and thus increase the competitiveness. Economic instruments, including carbon taxes and subsidies, and allocation of research and development resources, are driven by energy policy goals and can change the competitiveness of biomass energy

No abstract available