Fitness of backcross and F2 hybrids between weedy Brassica rapa and oilseed rape(B. napus)

Hauser, Thure P.; Jørgensen, Rikke Bagger; Østergård, Hanne

doi:10.1038/sj.hdy.6884250

Cited by 45 publications

(66 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No data were available for the survival of Br( )×F 1 zygotes in pods of mixed parentage, only data from single donor crosses in Hauser et al (1998a, b). To account for the effect of competition and preferential abortion, we calculated a 'competition factor' by scaling the survival of F 1 zygotes (relative to B. rapa) within mixed pods (0.48; Hauser et al, 1997) to their relative survival in single-donor pods (0.74; Hauser et al, 1998a; 'competition factor' = 0.65). The survival of backcross zygotes in mixed pods was then estimated by multiplying their survival in pure pods ((relative to B. rapa) = 0.62; Hauser et al, 1998b) with the competition factor: u 3·· = 0.62 × 0.65 = 0.40.…”

Section: Discussionmentioning

confidence: 99%

Male fitness of oilseed rape (Brassica napus), weedy B. rapa and their F1 hybrids when pollinating B. rapa seeds

Pertl

Hauser

Damgaard³

et al. 2002

Heredity

View full text Add to dashboard Cite

The likelihood that two species hybridise and backcross may depend strongly on environmental conditions, and possibly on competitive interactions between parents and hybrids. We studied the paternity of seeds produced by weedy Brassica rapa growing in mixtures with oilseed rape (B. napus) and their F 1 hybrids at different frequencies and densities. Paternity was determined by the presence of a transgene, morphology, and AFLP markers. In addition, observations of flower and pollen production, and published data on pollen fertilisation success, zygote survival, and seed germination, allowed us to estimate an expected paternity. The frequency and density of B. napus, B. rapa, and F 1 plants had a strong influence on flower, pollen, and seed production, and on the

show abstract

Section: Discussionmentioning

confidence: 99%

Male fitness of oilseed rape (Brassica napus), weedy B. rapa and their F1 hybrids when pollinating B. rapa seeds

Pertl

Hauser

Damgaard³

et al. 2002

Heredity

View full text Add to dashboard Cite

show abstract

“…In similar studies, Hauser et al (1998a) found that F 1 hybrids had intermediate fitness between the two parental species based on several combined characteristics, and they concluded that F 1 hybrids were significantly more fit than weedy B. rapa. In a subsequent study, Hauser et al (1998b), found that a fitness penalty occurred in F 2 and backcrossed individuals, although a small percentage of hybrids were as fit as the weedy parent. The fitness of F 1 hybrids may also be frequency dependent (based on hybrid versus parent ratio), and the experimental design in future research may need to include the appropriate ratio of hybrid to parental weedy B. rapa plants to simulate selection for the hybrids with the highest fitness (Pertl et al 2002;Hauser et al 2003).…”

Section: Female Parent)male Parent Citationmentioning

confidence: 99%

The Biology of Canadian Weeds. 137. Brassica napus L. and B. rapa L.

Gulden¹,

Warwick²,

Thomas³

2008

Can. J. Plant Sci.

View full text Add to dashboard Cite

. 2008. The Biology of Canadian Weeds. 137. Brassica napus L. and B. rapa. Can. J. Plan Sci. 88: 951Á996. Brassica napus and B. rapa are native to Eurasia. In Canada, these species are commonly referred to as volunteer canola, while feral populations of B. rapa are referred to as birdrape. Brassica napus and B. rapa have been grown commercially for their seed oil content in western Canada since the middle of the last century and volunteer populations are common in fields. Escaped populations of both species are also found along roadways, railways and in waste areas; however, only B. rapa is known to have naturalized, self-sustaining feral populations in these habitats in eastern Canada. Despite these escaped and feral populations, B. napus and B. rapa are mainly a concern in agricultural fields where their combined relative abundance has increased over the past few decades. In the mid 1990s, herbicideresistant genotypes of B. napus were released for commercial production. Herbicide-resistance and the stacking of genes in volunteer populations conferring resistance to multiple herbicides have contributed to increased difficulties in controlling volunteer B. napus in some crops. However, yield loss resulting from volunteer populations is not well documented in Canada.Key words: Brassica napus, Brassica rapa, herbicide resistance, transgene escape, volunteer canola, weed biology Gulden, R. H., Warwick, S. I. et Thomas, A. G. 2008. La biologie des mauvaises herbes au Canada. 137. Brassica napus L. et B. rapa L. Can. J. Plant Sci. 88: 951Á996. Brassica napus et B. rapa sont des plantes originaires d'Eurasie. Au Canada, on les de´signe souvent sous l'expression « canola spontane´», tandis que les peuplements sauvages de B. rapa sont appele´s « navette ». Dans l'Ouest canadien, Brassica napus et B. rapa sont cultive´s commercialement pour l'huile que renferment leurs graines depuis le milieu du sie`cle dernier et les repousses spontane´es sont devenues monnaie courante dans les champs. On observe des peuplements des deux espe`ces le long des routes et des voies ferre´es ainsi que dans les terrains vagues, cependant on sait que seule B. rapa s'est acclimate´e pour donner des populations sauvages et stables dans les meˆmes habitats, dans l'est du pays. Malgre´cela, B. napus et B. rapa demeurent surtout pre´occupants dans les cultures, oul eur abondance relative, une fois combine´s, s'est accrue au cours des dernie`res de´cennies. Au milieu des anne´e 1990, des ge´notypes de B. napus re´sistants aux herbicides ont e´te´homologue´s pour la culture commerciale. Cette re´sistance et l'accumulation des ge`nes qui la codent dans les peuplements spontane´s ont concouru a`compliquer la lutte contre les repousses de B. napus dans certaines cultures. Quoi qu'il en soit, les pertes de rendement qui en re´sultent sont mal e´taye´es au Canada.

show abstract

“…Mixing the parental genomes, especially by recombination in F 2 and later generation hybrids, may break up local adaptations and intrinsic coadaptations of gene complexes (Lynch, 1991), an effect called outbreeding depression. In the case of hybridization between polyploid cultivars and diploid relatives, chromosomal imbalances may add to a low fitness of hybrids (Hauser et al, 1998a). However, hybrids between cultivated and wild plants may sometimes exhibit improved fitness relative to their parents (Ellstrand, 2003), due to inheritance of beneficial crop alleles (Campbell et al, 2006), heterosis (Hauser et al, 1998b), and novel combinations of genes and traits of the parents (Hauser et al, 1998a;Hooftman et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…In the case of hybridization between polyploid cultivars and diploid relatives, chromosomal imbalances may add to a low fitness of hybrids (Hauser et al, 1998a). However, hybrids between cultivated and wild plants may sometimes exhibit improved fitness relative to their parents (Ellstrand, 2003), due to inheritance of beneficial crop alleles (Campbell et al, 2006), heterosis (Hauser et al, 1998b), and novel combinations of genes and traits of the parents (Hauser et al, 1998a;Hooftman et al, 2005). Transgression of traits from the two parents is thought to be a major mechanism for creating evolutionary novelties in hybrids (Lexer et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Hybrids between cultivated and wild carrots in natural populations in Denmark

Magnussen

Hauser

2007

Heredity

View full text Add to dashboard Cite

Many cultivated plant species are able to hybridize with related wild plants. However, it is not clear whether their hybrids are able to survive and reproduce outside managed fields, and if cultivar genes introgress into wild populations. In areas where wild carrots co-occur with carrot root-crops, pollen and seeds may flow from two different sources in the fields to the surrounding wild populations: from pure cultivar plants that occasionally flower, and from flowering 'bolters' that originate from hybridizations between wild (#) and cultivated carrots (~) in seed production fields in warmer regions of the world. To test whether hybrids are formed and survive in wild Danish populations, and whether prolonged hybridization has led to introgression of cultivar genes, we collected leaf material from adult individuals growing close to carrot fields and analysed their genotypic composition by AFLP. Four hybrids were identified among the 71 plants analysed, and these were most likely F 2 or backcross individuals, sired by pollen from hybrid bolters. Wild populations close to fields were genetically somewhat more similar to cultivars than wild populations far from fields, suggesting that neutral or beneficial cultivar alleles can introgress into the wild gene pool. Despite generations of improvement and adaptation of cultivar carrots to highly managed field conditions, hybrids can thus sometimes survive in wild populations close to carrot fields, and their genes transfer to wild populations by introgression.

show abstract

Fitness of backcross and F2 hybrids between weedy Brassica rapa and oilseed rape(B. napus)

Cited by 45 publications

References 7 publications

Male fitness of oilseed rape (Brassica napus), weedy B. rapa and their F1 hybrids when pollinating B. rapa seeds

Male fitness of oilseed rape (Brassica napus), weedy B. rapa and their F1 hybrids when pollinating B. rapa seeds

The Biology of Canadian Weeds. 137. Brassica napus L. and B. rapa L.

Hybrids between cultivated and wild carrots in natural populations in Denmark

Contact Info

Product

Resources

About