Extending the rapeseed gene pool with resynthesized Brassica napus II: Heterosis

Hybrid breeding relies on the combination of parents from two differing heterotic groups. However, the genetic diversity in adapted oilseed rape breeding material is rather limited. Therefore, the use of resynthesized Brassica napus as a distant gene pool was investigated. Hybrids were derived from crosses between 44 resynthesized lines with a diverse genetic background and two male sterile winter oilseed rape tester lines. The hybrids were evaluated together with their parents and check cultivars in 2 years and five locations in Germany. Yield, plant height, seed oil, and protein content were monitored, and genetic distances were estimated with molecular markers (127 polymorphic RFLP fragments). Resynthesized lines varied in yield between 40.9 dt/ha and 21.5 dt/ha, or between 85.1 and 44.6% of check cultivar yields. Relative to check cultivars, hybrids varied from 91.6 to 116.6% in yield and from 94.5 to 103.3% in seed oil content. Mid-parent heterosis varied from −3.5 to 47.2% for yield. The genetic distance of parental lines was not significantly correlated with heterosis or hybrid yield. Although resynthesized lines do not meet the elite rapeseed standards, they are a valuable source for hybrid breeding due to their large distance from present breeding material and their high heterosis when combined with European winter oilseed rape

Application of a multivariate, mixed model to experimental data coming from the field of plant breeding.

International audienc

Les distances genetiques : estimations et applications.

ISBN 2-85340-728-4National audienc

Les distances genetiques : estimations et applications.

ISBN 2-85340-728-4National audienc

Heterosis and genetic distance in rapeseed (Brassica napus L.): crosses between European and Asiatic selfed lines

International audienc

Heterosis and genetic distance in rapeseed (Brassica napus L.): crosses between European and Asiatic selfed lines

International audienc

Variabilite genetique en croisement intra et interpopulation dans deux populations de mais fourrage

National audienceThe intra- and interpopulation genetic variability was studied in 2 forage maize populations at Co and C1 cycles of selection, from nested mating designs. The following traits were studied: flowering earliness, plant and ear heights, length and width of ear leaf, whole-plant yield and dry matter content. The nature of genetic variance was the same in intrapopulation and in interpopulation progenies: for yield and length of ear leaf, the dominance variance was significant; for the other traits, the additive variance explained most of the genetic variability. The intrapopulation and interpopulation additive variances were similar for highly heritable traits (heights and earliness) and were quite different for yield. The male plant average effects, estimated in intrapopulation and in interpopulation, were related: correlations were positive for all traits, lower for low heritable traits. Results were consistent with those reviewed from different selection experiments. Conclusions for breeding methods were then suggested.A la suite d’un plan de croisement hiérarchique, la variabilité génétique révélée en croisement intra- et interpopulation dans 2 populations de maïs fourrage a été analysée aux cycles Co et C1 de sélection. Les caractères étudiés sont les suivants : précocité de floraison, hauteur totale, hauteur de l’épi, longueur et largeur de la feuille de l’épi, rendement de la plante entière et teneur en matière sèche. La nature de la variabilité génétique est la même pour les 2 types de descendances : prépondérance des effets de dominance pour le rendement et à un moindre degré pour la longueur de la feuille; prépondérance des effets additifs pour tous les autres caractères. La variance d’additivité est de même importance en croisement intra- et interpopulation pour les caractères fortement héritables (mesures morphologiques et précocité), mais d’amplitude un peu plus variable pour le rendement. La corrélation entre les effets moyens des plantes mâles estimés en croisement intra- et interpopulation est positive pour tous les caractères, et d’autant plus faible que les caractères sont moins héritables. Les résultats sont en accord avec ceux de différentes expériences de sélection chez le maïs. Les conséquences de cette étude sur les méthodes de sélection sont discutées

Prediction de l'heterosis a partir de plans de croisements top-cros : interet de la distance de Hanson et Casas

National audienc

De nouvelles perspectives pour l'analyse genetique des caracteres quantitatifs. 2 : la selection assistee par marqueurs

National audienc