1.
Albert, Frank W., et al.
(författare)
Genetic architecture of tameness in a rat model of animal domestication
2009
Ingår i: Genetics. - : Oxford University Press (OUP). - 0016-6731 .- 1943-2631. ; 182:2, s. 541-554
Tidskriftsartikel (refereegranskat) abstract
A common feature of domestic animals is tameness - i.e., they tolerate and are unafraid of human presence and handling. To gain insight into the genetic basis of tameness and aggression, we studied an intercross between two lines of rats (Rattus norvegicus) selected over >60 generations for increased tameness and increased aggression against humans, respectively. We measured 45 traits, including tameness and aggression, anxiety-related traits, organ weights, and levels of serum components in >700 rats from an intercross population. Using 201 genetic markers, we identified two significant quantitative trait loci (QTL) for tameness. These loci overlap with QTL for adrenal gland weight and for anxiety-related traits and are part of a five-locus epistatic network influencing tameness. An additional QTL influences the occurrence of white coat spots, but shows no significant effect on tameness. The loci described here are important starting points for finding the genes that cause tameness in these rats and potentially in domestic animals in general.
2.
3.
Denoyes-Rothan, B., et al.
(författare)
Anthracnose on strawberry in France : Situation and perspectives
2006
Ingår i: Proceedings of the Vth International Strawberry Symposium. - : INTERNATIONAL SOCIETY HORTICULTURAL SCIENCE. ; , s. 277-280
Konferensbidrag (refereegranskat) abstract
Anthracnose, caused by Colletotrichum acutatum, on strawberry (Fragaria x ananassa) was first reported on fruit in France in 1981. Damage was later recorded on runners, petioles, foliage and crowns. The evolution of a disease control method, the molecular variability of C acutatum, the study of the interaction between pathogen and host, the different techniques of inoculation, and the last results concerning QTLs linked to resistance to C acutatum are reported, which cover 10 years of research in France.
4.
Dida, Mulatu Geleta, et al.
(författare)
Inter simple sequence repeat (ISSR) based analysis of genetic diversity of Lobelia rhynchopetalum (Campanulaceae)
2009
Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661 .- 1601-5223. ; 146, s. 122-130
Tidskriftsartikel (refereegranskat) abstract
An understanding of the patterns of genetic variation within and among populations of plant species is essential for devising optimum genetic management strategies for their conservation. Here, the inter simple sequence repeat (ISSR) technique was used to study genetic variation of the Afroalpine giant lobelia, Lobelia rhynchopetalum, based on ten populations sampled from Bale and Simen mountains in Ethiopia. The percentage of polymorphic loci across all samples (P(S)) and within population (Pp) was 78% and 27%, respectively. Regardless of a high total genetic variation, the species has quite low variation within populations. All genetic variation analyses revealed higher variation among populations than within populations (G'(ST) = 0.59, G(ST) = 0.63, F(ST) = 0.58). Analysis of molecular variance (AMOVA) that employed 156 ISSR markers revealed significant variations among populations; among the two mountain systems and among the three altitudinal groups (P < 0.001). The implications of these findings are discussed, especially from conservation point of view.
5.
Lerceteau-Köhler, Estelle, et al.
(författare)
Identification of SCAR markers linked to Rca2 anthracnose resistance gene and their assessment in strawberry germplasm
2005
Ingår i: Theoretical and Applied Genetics. - : SPRINGER. - 0040-5752 .- 1432-2242. ; 111:5, s. 862-870
Tidskriftsartikel (refereegranskat) abstract
Bulked segregant analysis combined with AFLPs was used to identify molecular markers linked to the Rca2 gene conferring resistance to Colletotrichum acutatum pathogenicity group 2 which causes anthracnose in the octoploid strawberry Fragaria x ananassa. DNA bulks originating from a cross between the resistant cultivar ‘Capitola’ and the susceptible cultivar ‘Pajaro’ were screened with 110 EcoRI/MseI AFLP combinations. Four AFLP markers were found linked in coupling phase to Rca2 with recombination percentages between 0% and 17.7%. Among the four markers linked to the resistance gene, two were converted into SCAR markers (STS-Rca2_417 and STS-Rca2_240) and screened in a large segregating population including 179 genotypes. The Rca2 resistance gene was estimated to be 0.6 cM from STS-Rca2_417 and 2.8 cM from STS-Rca2_240. The presence/absence of the two SCAR markers was further studied in 43 cultivars of F. x ananassa, including 14 susceptible, 28 resistant, and one intermediate genotype. Results showed that 81.4% and 62.8% of the resistant/susceptible genotypes were correctly predicted by using STS-Rca2_417 and STS-Rca2_240, respectively. The 14 susceptible genotypes showed no amplification for either SCARs. These developed SCARs constitute new tools for indirect selection criteria of anthracnose resistance genotypes in strawberry breeding programs.
6.
Lerceteau-Köhler, Estelle, et al.
(författare)
QTL analysis for sugars and organic acids in strawberry fruits
2006
Ingår i: Proceedings of the Vth International Strawberry Symposium. - : INTERNATIONAL SOCIETY HORTICULTURAL SCIENCE. ; , s. 573-577
Konferensbidrag (refereegranskat) abstract
Improving fruit quality is an important goal for strawberry breeders. Quantitative trait loci (QTL) for fruit quality of cultivated strawberry (Fragaria x ananassa Duch.) have been identified. A segregating population of 213 individuals of a cross between ‘Capitola’ and ‘CF1116’, two genotypes with many contrasting fruit quality traits, was used in the study. Eleven traits related to sugar and acid content were evaluated for all progeny and for both parents. These traits were quantified by enzymatic and metabolic profiling using one-dimensional H-1-NMR. Depending on the trait, measurements were taken over two or three years. Progeny showed a large range of variation for most of the traits. The strongest positive correlations were observed between fructose and glucose contents, and citrate and sum of organic acids. A total of 30 significant QTLs were detected by composite interval mapping (LOD superior to LODthreshold =2.88) and spread over eight female linkage groups and seven male linkage groups in coupling phase with a percentage of variation explained by a QTL ranging from 5.7 to 14.1%. Strong co-locations of putative QTLs for fructose and glucose were detected, while other QTLs were detected for sucrose.
7.
Mgbeahuruike, Anthony Christian
(författare)
A study of the traits associated with the biocontrol activity of Phlebiopsis gigantea
2009
Licentiatavhandling (övrigt vetenskapligt/konstnärligt) abstract
Phlebiopsis gigantea has routinely been used for the biocontrol of the conifer pathogen, Heterobasidion annosum s.l. but the mechanism for the biocontrol action has not been properly understood. In the present work, 64 isolates of P. gigantea were screened for traits important for the biocontrol of H. annosum. Growth rate and the interaction patterns of H. annosum s.l. and P.gigantea were studied in both carbon rich (Hagem) and low carbon media (Norkrans). Laccase assay and wood degradation capabilities were performed on the 64 isolates. Data was analyzed with multiple regression and principal component analysis. Results showed a significant effect of culture composition on the outcome of the interaction, 90 % of the isolates were able to displace H. annosum s.s. in sawdust media after 20 days, as compared with only 4% recorded in the glucose rich Hagem media. High growth rate on sawdust, a lignified carbon source, correlated with high growth rate in ferulic acid, a lignin precursor (P = 0.078), high growth rate in xylan, a hemicellulose (P = 0.001) and percentage weight loss in pine (P = 0.01). Interaction in sawdust correlated with high wood degradation capability in pine and spruce with P-values (P = 0.01, P = 0.03) respectively, high growth rate in xylan (P = 0.01), laccase production (P = 0.08), interaction in Hagem (P = 0.01) and mean growth rate at 10 °C (P = 0.001). Additionally, the role of hydrophobin in the competitive interaction was further investigated. The genomic sequence of Phlebiopsis gigantea hydrophobins 1 and 2 (Pgh1 and Pgh2) from a subset of isolates selected on the basis of geographical origins and antagonistic abilities was investigated. Similarly, the expression of Pgh1 and Pgh2 under different substrate conditions was also studied using quantitative PCR. Sequence analysis was performed with Clustal W and inspected with Megalign (DNA Star). Expression data was analyzed using the relative quantification method- 2-ΔΔCt and tested for effects of isolates, genes and culture conditions using the general linear model (GLM) procedure in SAS. There was a close sequence similarity between hydrophobin genes of isolates having different antagonistic capabilities and from different geographical sources. Higher transcript levels of Pgh1 and Pgh2 were recorded in submerged cultures compared with aerial conditions. The effect of substrate on the expression of the two genes (Pgh1 and Pgh2) was statistically significant (P = 0.0001). Differences in transcript levels of Pgh1 and Pgh2 were also observed among isolates belonging to different antagonistic categories. Overall, the results suggests that the antagonistic and competitive advantage of P. gigantea, hinged on the ability of the isolates to degrade the different structural components of wood. A significant correlation was also found between some high antagonistic isolates and the expression of hydrophobin genes (Pgh1 and Pgh2). The significance of these results in the biological control is discussed.
8.
Rousseau-Gueutin, Mathieu, et al.
(författare)
Comparative genetic mapping between octoploid and diploid Fragaria species reveals a high level of colinearity between their genomes and the essentially disomic behavior of the cultivated octoploid strawberry
2008
Ingår i: Genetics. - : OXFORD UNIV PRESS INC. - 0016-6731 .- 1943-2631. ; 179:4, s. 2045-2060
Tidskriftsartikel (refereegranskat) abstract
Macrosynteny and colinearity between Fragaria (strawberry) species showing extreme levels of ploidy have been studied through comparative genetic mapping between the octoploid cultivated strawberry. (F x ananassa) and its diploid relatives. A comprehensive map of the octoploid strawberry, in which almost all linkage groups are ranged into the seven expected homoeologeous groups was obtained, thus providing were observed between homo(eo)logous linkage groups and between the octoploid homoeologous groups and their corresponding diploid linkage groups. These results reveal that the polyploidization events that took place along the evolution of the Fragaria genus and the more recent juxtaposition of two octoploid strawberry genomes in the cultivated strawberry did not trigger any major chromosomal rearrangements in genomes involved in F. x ananassa. They further suggest the existence of a close levels of polysomic segregation suggested by the observation of large linkage groups in coupling phase only, the prevalence of linkage groups in coupling/replusion phase clearly demonstrates that the meiotic behavior is mainly disomic in the cultivated strawberry.
