Genotype and environment interaction on yield and quality parameters of organically grown winter wheat – Triticum aestivum L. genotypes

The interaction of genotype and environment upon yield and quality parameters of eight winter wheat (Triticum aestivum L.) genotypes was studied under organic conditions in Austria over two growing periods, 2001/2002 and 2002/2003, respectively. Two sites that have significantly different climatic conditions, Innviertel and Marchfeld, were chosen for the field experiment. Study site weather and soil conditions are important yield-affecting factors. Although the yield of Marchfeld-grown genotypes were lower, they had shown higher quality parameter values. Soil moisture conditions increase the grain yield but decrease its quality. To obtain seed with higher quality, a production site with favourable climate conditions should be chosen

Potential of ten alternative grass species under different cutting regimes in Central Europe

Die Bedeutung von mehrjährigem Grasland als großflächige CO2-Senke ist hoch. Auf diesen Flächen könnten neben Futtermitteln auch Nachwachsende Rohstoffe ökologisch verträglich produziert werden. Aufgrund des fortschreitenden Klimawandels werden die Grünlandflächen Mitteleuropas künftig häufiger von Trockenheit betroffen sein als bisher.Um deren Anbaupotenzial unter mitteleuropäischen Bedingungen zu testen, wurden zehn trockentolerante Gräser (Agropyron elongatum, Agropyron intermedium, Agropyron desertorum, Agropyron trachycaulum, Elymus hoffmannii, Elymus junceus, Bromus inermis, Bromus marginatus, Festuca arundinacea und Panicum virgatum) angebaut und mit vier standortüblichen, leistungsfähigen Futtergräsern in Vergleich gestellt (Dactylis glomerata, Arrhenatherum elatius, Agrostis gigantea und Agropyron repens). Die Parzellenversuche wurden an zwei Stand­orten über zwei Versuchsjahre bei Ein- und Mehrschnittnutzung durchgeführt.Bei Einschnittnutzung lieferte P. virgatum den höchsten bereinigten Jahresertrag (14 258 kg TM ha–1), gefolgt von A. elongatum (13 086 kg TM ha–1). Die mehrjährige Ausdauer dieser zwei Arten war unter den Versuchs­bedingungen aber nur gegeben, wenn P. virgatum nicht vor dem Abfrosten und A. elongatum nur einmal pro Jahr geerntet wurde. Die Lageranfälligkeit der beiden Arten muss beachtet werden. Bei Mehrschnittnutzung konnte F. arundinacea sowohl in der Ertragshöhe (12 533 kg TM ha–1 korrigierter Jahresertrag) als auch durch das geringe Aufkommen an Begleitflora (0,1% Fläche) überzeugen. Beim Anbau dieser Grasart ist die nur mäßige Konkurrenzkraft während der Etablierungsphase zu berücksichtigen. Aufgrund der raschen Jungendentwicklung von A. trachycaulum wird erwartet, dass sich die Art für den Einsatz als Deckfrucht in Saatgutmischungen eignet. A. desertorum, A. trachycaulum, A. repens, E. junceus und B. marginatus lagen im Ertrag unterhalb des Versuchsdurchschnittes (9254,5 kg DM ha–1 bei Zweischnittnutzung). DOI: 10.5073/JfK.2014.06.01, https://doi.org/10.5073/JfK.2014.06.01Perennial grasslands play an important role as an extensive CO2 sink. Fodder and biofuels can be produced in an ecologically acceptable manner on such sites. Projected future climate-change scenarios suggest that Central Europe’s grasslands will be increasingly affected by drought. In order to determine whether there is potential for some alternative drought-adapted grass species to contribute to herbage production for either forage or biomass, we tested the agronomic performance of ten grass species (Agropyron elongatum, Agropyron intermedium, Agropyron desertorum, Agropyron trachycaulum, Elymus hoffmannii, Elymus junceus, Bromus inermis, Bromus marginatus, Festuca arundinacea and Panicum virgatum) in comparison to four reference grasses (Dactylis glomerata, Arrhenatherum elatius, Agrostis gigantea and Agropyron repens). Experiments were conducted in small-plot cutting trials at two sites across two growing seasons with either one or multiple cuts per season.In the one-cut system, P. virgatum provided the highest average annual dry matter (DM) yield (14 258 kg ha–1), followed by A. elongatum (13 086 kg ha–1). The multi-annual persistence of these two species under the experimental conditions was given only when P. virgatum was not harvested before freezing off and A. elongatum was harvested only once per year. Moreover, both species are susceptible to lodging. In the multiple-cut system, F. arundinacea showed a high yield (12 533 kg DM ha–1 average annual yield) and a low presence of associated weeds (only 0.1% surface area). Cultivating this grass species requires considering its only moderate competitiveness during the establishment phase. Based on the rapid establishment of A. trachycaulum, this species is expected to be best suited as a cover crop in seed mixtures. The yields of A. desertorum, A. trachycaulum, A. repens, E. junceus and B. marginatus were below the experimental average (9255 kg DM ha–1 at multiple cuttings). DOI: 10.5073/JfK.2014.06.01, https://doi.org/10.5073/JfK.2014.06.0

Mapping quantitative physiological traits in apple ( Malus × domestica Borkh.)

Efficient breeding and selection of high-quality apple cultivars requires knowledge and understanding of the underlying genetics. The availability of genetic linkage maps constructed with molecular markers enables the detection and analysis of major genes and quantitative trait loci contributing to the quality traits of a genotype. A segregating population of the cross between the apple varieties 'sFiesta' (syn. 'sRed Pippin') and 'sDiscovery' has been observed over three years at three different sites in Switzerland and data on growth habit, blooming behaviour, juvenile period and fruit quality has been recorded. QTL analyses were performed, based on a genetic linkage map consisting of 804 molecular markers and covering all 17 apple chromosomes. With the maximum likelihood based interval mapping method, the investigated complex traits could be dissected into a number of QTLs affecting the observed characters. Genomic regions participating in the genetic control of stem diameter, plant height increment, leaf size, blooming time, blooming intensity, juvenile phase length, time of fruit maturity, number of fruit, fruit size and weight, fruit flesh firmness, sugar content and fruit acidity were identified and compared with previously mapped QTLs in apple. Although 'sDiscovery' fruit displayed a higher acid content, both acidity QTLs were attributed to the sweeter parent 'sFiesta'. This indicated homozygosity at the acidity loci in 'sDiscovery' preventing their detection in the progeny due to the lack of segregatio

Molecular markers linked to the apple scab resistance gene Vbj derived from Malus baccata jackii

Breeding for scab-resistant apple cultivars by pyramiding several resistance genes in the same genetic background is a promising way to control apple scab caused by the fungus Venturia inaequalis. To achieve this goal, DNA markers linked to the genes of interest are required in order to select seedlings with the desired resistance allele combinations. For several apple scab resistance genes, molecular markers are already available; but until now, none existed for the apple scab resistance gene Vbj originating from the crab apple Malus baccata jackii. Using bulk segregant analysis, three RAPD markers linked to Vbj were first identified. These markers were transformed into more reliable sequence-characterised amplified region (SCAR) markers that proved to be co-dominant. In addition, three SSR markers and one SCAR were identified by comparing homologous linkage groups of existing genetic maps. Discarding plants showing genotype-phenotype incongruence (GPI plants) plants, a linkage map was calculated. Vbj mapped between the markers CH05e03 (SSR) and T6-SCAR, at 0.6cM from CH05e03 and at 3.9cM from T6-SCAR. Without the removal of the GPI plants, Vbj was placed 15cM away from the closest markers. Problems and pitfalls due to GPI plants and the consequences for mapping the resistance gene accurately are discussed. Finally, the usefulness of co-dominant markers for pedigree analysis is also demonstrate

Effects of tillage systems and mechanization on work time, fuel and energy consumption for cereal cropping in Austria

The machinery stock, fuel consumption and work time are crucial economic factors for the profit potential in the arable farming sector.  The influence of five soil tillage systems (two conventional tillage systems and three conservation tillage systems) and two tractor sizes (92 kW-tractor and 59 kW-tractor) on work time, fuel and energy consumption was measured in the semi-arid region in Austria.  The tractors were equipped with a high-performance flow meter and a radar sensor to measure the fuel consumption (L h-1) and working speed (km h-1).  The conventional tillage with mouldboard plough has the highest working time and fuel consumption rate.  The replacement of plough with a cultivator, reduces the work time and fuel consumption for soil tillage as well as the energy consumption per moved soil matter to more than 50% roughly.  The highest saving effects (more than 85%) were achieved with the direct drilling without soil tillage system.  A well loaded engine in a small tractor with small implements is more fuel efficient than a worse loaded engine in a “big tractor”.  An adjusted tractor-implement combination, which is well implemented in the 59-kW mechanization, decreases the fuel consumption to up to 30% and 46%.  Due to lower field capacity in the 59-kW mechanization, the work time is higher between 2.4% and 11.7%.   Keywords: fuel consumption, mechanization, tillage system, work tim

Molecular markers linked to the apple scab resistance gene Vbj derived from Malus baccata jackii

Breeding for scab-resistant apple cultivars by pyramiding several resistance genes in the same genetic background is a promising way to control apple scab caused by the fungus Venturia inaequalis. To achieve this goal, DNA markers linked to the genes of interest are required in order to select seedlings with the desired resistance allele combinations. For several apple scab resistance genes, molecular markers are already available; but until now, none existed for the apple scab resistance gene Vbj originating from the crab apple Malus baccata jackii. Using bulk segregant analysis, three RAPD markers linked to Vbj were first identified. These markers were transformed into more reliable sequence-characterised amplified region (SCAR) markers that proved to be co-dominant. In addition, three SSR markers and one SCAR were identified by comparing homologous linkage groups of existing genetic maps. Discarding plants showing genotype\u2013phenotype incongruence (GPI plants) plants, a linkage map was calculated. Vbj mapped between the markers CH05e03 (SSR) and T6-SCAR, at 0.6 cM from CH05e03 and at 3.9 cM from T6-SCAR. Without the removal of the GPI plants, Vbj was placed 15 cM away from the closest markers. Problems and pitfalls due to GPI plants and the consequences for mapping the resistance gene accurately are discussed. Finally, the usefulness of co-dominant markers for pedigree analysis is also demonstrated

Integration of physical and genetic maps in apple confirms whole-genome and segmental duplications in the apple genome

A total of 355 simple sequence repeat (SSR) markers were developed, based on expressed sequence tag (EST) and bacterial artificial chromosome (BAC)-end sequence databases, and successfully used to construct an SSR-based genetic linkage map of the apple. The consensus linkage map spanned 1143 cM, with an average density of 2.5 cM per marker. Newly developed SSR markers along with 279 SSR markers previously published by the HiDRAS project were further used to integrate physical and genetic maps of the apple using a PCR-based BAC library screening approach. A total of 470 contigs were unambiguously anchored onto all 17 linkage groups of the apple genome, and 158 contigs contained two or more molecular markers. The genetically mapped contigs spanned ∼421 Mb in cumulative physical length, representing 60.0% of the genome. The sizes of anchored contigs ranged from 97 kb to 4.0 Mb, with an average of 995 kb. The average physical length of anchored contigs on each linkage group was ∼24.8 Mb, ranging from 17.0 Mb to 37.73 Mb. Using BAC DNA as templates, PCR screening of the BAC library amplified fragments of highly homologous sequences from homoeologous chromosomes. Upon integrating physical and genetic maps of the apple, the presence of not only homoeologous chromosome pairs, but also of multiple locus markers mapped to adjacent sites on the same chromosome was detected. These findings demonstrated the presence of both genome-wide and segmental duplications in the apple genome and provided further insights into the complex polyploid ancestral origin of the apple

Differentiation in populations of the apple scab fungus Venturia inaequalis on cultivars in a mixed orchard remains over time

The ascomycete Venturia inaequalis causes annual epidemics of apple scab worldwide. Scab development is reduced in mixed cultivar orchards compared with monocultures. To use mixtures in commercial production, we need to understand how the population of scab changes in a mixed orchard and how likely a super race, with virulence factors overcoming multiple resistance factors in the mixed orchard, is to emerge and become dominant. We used short sequence repeat (SSR) markers to investigate the temporal change of scab populations in two mixed cultivar orchards in the UK to infer the likelihood of emergence of a scab super race. There were no significant differences between the populations at the two sampling times (six or seven years apart) in either of the two mixed orchards. In one of the orchards apple scab populations on different cultivars were significantly different and the differences did not diminish over time. These results suggest that it is not inevitable that a super race of V. inaequalis will become dominant during the lifetime of a commercial apple orchard