Breeding Material (breeding + material)

Distribution by Scientific Domains

Selected Abstracts

Mapping of QTL for resistance against Fusarium head blight in the winter wheat population Pelikan//Bussard/Ning8026

PLANT BREEDING, Issue 1 2009
J. Häberle
Abstract We report on the identification of FHB (Fusarium head blight) resistance quantitative trait loci (QTL) of the donor ,G93010' (Bussard/Ning8026) in the background of elite breeding material adapted to the central European climate. With a multiple interval mapping method, two major resistance QTL were identified. Qfhs.lfl-7BS/5BL and Qfhs.lfl-6BS reduced FHB severity individually by 30% and 24%. The combination of both QTL decreased disease severity most effectively by about one half. Qfhs.lfl-6BS is most likely identical to Fhb2, thus, the effectiveness of Fhb2 in central European breeding material has been validated. Qfhs.lfl-7BS/5BL overlapped with QTL for plant height and heading date. Nevertheless, the selection of lines combining a good FHB resistance level with an acceptable plant height was possible. As the donors of the QTL have probably not yet been utilized in European breeding material, we identified well-adapted lines of the mapping population as valuable donors for marker-assisted breeding programmes. [source]

Nitrogen uptake and utilization efficiency of European maize hybrids developed under conditions of low and high nitrogen input

PLANT BREEDING, Issue 6 2002
T. Presterl
Abstract Maize varieties with improved nitrogen(N)-use efficiency under low soil N conditions can contribute to sustainable agriculture. Tests were carried to see whether selection of European elite lines at low and high N supply would result in hybrids with differential adaptation to these contrasting N conditions. The objective was to analyze whether genotypic differences in N uptake and N-utilization efficiency existed in this material and to what extent these factors contributed to adaptation to low N supply. Twenty-four hybrids developed at low N supply (L × L) were compared with 25 hybrids developed at high N supply (H × H). The N uptake was determined as total above-ground N in whole plants, and N-utilization efficiency as the ratio between grain yield and N uptake in yield trials at four locations and at three N levels each. Highly significant variations as a result of hybrids and hybrids × N-level interaction were observed for grain yield as well as for N uptake and N-utilization efficiency in both hybrid types. Average yields of the L × L hybrids were higher than those of the H × H hybrids by 11.5% at low N supply and 5.4% at medium N level. There was no significant yield difference between the two hybrid types at high N supply. The L × L hybrids showed significantly higher N uptake at the low (12%) and medium (6%) N levels than the H × H hybrids. In contrast, no differences in N-utilization efficiency were observed between the hybrid types. These results indicate that adaptation of hybrids from European elite breeding material to conditions with reduced nitrogen input was possible and was mainly the result of an increase in N-uptake efficiency. [source]

Distribution and properties of geographically distinct isolates of sugar beet yellowing viruses

M. Stevens
From a total of 261 yellow sugarbeet leaves collected from 10 countries representing three continents, the incidence and distribution of strains of Beet mild yellowing virus (BMYV), Beet chlorosis virus (BChV) and Beet yellows virus (BYV) were analysed using serological and molecular methods. BMYV was found in all countries except Greece, and more frequently in the northern and western areas of Europe, whereas BYV predominated in Turkey, Spain, Greece, the USA and Chile. BChV, originally found in the USA and the UK in 1989, was identified in France, Spain, the Netherlands and Chile. Nine sugar beet poleroviruses, plus a reference isolate of Turnip yellows virus (TuYV, syn. Beet western yellows virus), were further characterized and compared. Isolates obtained from sugar beet infected this species, but not oilseed rape or lettuce; all isolates except one infected Capsella bursa-pastoris. The coat-protein sequences of these isolates were highly similar, with the consensus sequence representing 89% of nucleotide residues. Within the coat-protein gene, two regions were identified that could represent specific epitopes to which monoclonal antibody BYDV-PAV-IL-1 could bind; this antibody is used to distinguish beet poleroviruses in ELISA. Comparison of the sequences at the 5, end showed that sequence homology existed only between isolates with the same host range. The first sequence data of polerovirus isolates from Chile are presented, showing that the coat protein and the 5, end of their genomes are highly similar to those of BMYV isolates found in Europe. Chilean polerovirus isolates may have been imported from the northern hemisphere in sugar beet breeding material. [source]

Analysis of the morphological attributes of a sweetpotato collection

M.M. Manifesto
The knowledge about the distribution of descriptors of a collection constitutes a useful tool for the management of genetic resources. The object of this work was to evaluate the composition and morphological characterisation of the ,in vitro' collection kept at the Gene Bank of the Biological Resources Institute (IRB), INTA Castelar, Argentina, to establish conservation criteria and make available useful data for breeding programmes. This collection, comprising 310 sweetpotato clones, includes landraces, worldwide clones, commercial varieties and breeding material. The descriptors, which presented the highest correlation values, were leaf lobe types, the shape of central leaf lobes and general leaf outline. Cluster analyses showed eight major groups with an average similarity of 0.42 (SE ± 0.005). About 76% of the clones presented unique morphology, whereas 34% of them were distributed in 22 groups that could not be distinguished with this technique. Worldwide germplasm formed a separate group with values of diversity higher than those of the Argentinean clones and no duplicates. A projection of the phenotypic variation among cultivars was obtained through Principal Coordinate Analysis (PCoorA), which confirmed the results obtained by UPGMA analysis, predominant skin colour, secondary skin colour, number of leaf lobes, general leaf outline, petiole pigmentation and predominant colour of vine were the variables that made the highest contribution. Collection composition in reference to flesh and skin colour was also analysed. [source]

Consequences of a decentralized participatory barley breeding programme on changes in SSR allele frequency and diversity in one cycle of selection

PLANT BREEDING, Issue 5 2007
F. Fufa
Abstract Changes in allele type, allele frequency and genetic diversity because of selection by individual farmers and breeders were assessed using simple sequence repeats (SSRs) during one cycle of selection in a decentralized participatory barley breeding programme. Selection by both breeders and farmers resulted in the loss of a number of alleles in the majority of the locations, with more alleles lost in the heterogeneous breeding materials than in the fixed genotypes, indicating selection against undesirable traits uncovered in the heterogeneous breeding materials that are presumably linked to SSR alleles. After selection, significant allelic frequency changes were observed at several loci in both the germplasm groups. As the selection was conducted independently in each location, an allele had a chance of being selected in more than one location, and therefore considering the whole study area the allelic composition and diversity of the original genetic materials was maintained after the selection. The study showed the importance of decentralized participatory plant breeding in maintaining genetic diversity that helps stabilize and sustain production in unpredictable production conditions. [source]

Quantitative-genetic analysis of leaf-rust resistance in seedling and adult-plant stages of inbred lines and their testcrosses in winter rye

PLANT BREEDING, Issue 6 2002
T. Miedaner
Abstract Leaf rust is the most frequent leaf disease of winter rye in Germany. All widely grown population and hybrid varieties are susceptible. This study was undertaken to estimate quantitative-genetic parameters of leaf-rust resistance in self-fertile breeding materials with introgressed foreign leaf-rust resistances and to analyze the relative importance of seedling and adult-plant resistance. Forty-four inbred lines and their corresponding testcrosses with a highly susceptible tester line were grown in a field in four different environments (location-year combinations) with artificial inoculation. Plots were separated by a nonhost to promote autoinfections and minimize interplot interference. Leaf-rust severity was rated on three leaf insertions at three dates. The testcrosses showed a considerably higher disease severity than the lines. High correlations (r , 0.9, P = 0.01) existed among the leaf insertions and the rating dates. Large genotypic variation for resistance was found in both the inbred and testcross populations. Genotype-environment interaction and error variances were of minor importance, thus high entry-mean heritabilities were achieved. A tight correlation between the inbreds and their corresponding testcrosses was found (r = 0.88, P = 0.01). Heterosis for resistance was significant (P = 0.05), but not very important. In a seedling test with 20,30 single-pustule isolates, 34 out of 44 inbreds reacted race-specifically. From the remaining inbred lines, three were medium and seven highly susceptible. In a further greenhouse test with 16 inbreds, seven were susceptible and five were resistant in both seedling and adult-plant stages. The remaining four lines had adult-plant resistance. In conclusion, race-specific leaf-rust resistance can be selected among inbred lines per se. Lines should also be tested in the adult-plant stage. [source]