B. Andersen

The Ohio State University, Columbus, Ohio, United States

Are you B. Andersen?

Claim your profile

Publications (11)20.36 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: AFLP markers were used to characterize diversity and asses the genetic structure among 17 accessions of kale landraces, cultivars and wild populations from Europe. The range of average gene diversity in accessions was 0.11–0.27. Several landraces showed higher levels of diversity than the wild populations and one cultivar had the lowest diversity measures. The landraces that were most genetically diverse were from areas where kales are known to be extensively grown, suggesting in situ conservation in these areas as a supplement to storage of seeds in gene banks. An analysis of molecular variance (AMOVA) showed that 62% of the total variation was found within accessions. For most accessions, genetic distance was not related to geographic distance. Similarities among accessions were probably not caused by recent gene flow since they were widely separated geographically; more likely the relationship among them is due to seed dispersal through human interactions. Our results indicate that a kale population found in a natural habitat in Denmark was probably not truly wild but most likely an escape from a cultivated Danish kale that had subsequently become naturalized. Keywords Brassica oleracea –Genetic resources–Molecular markers–Genetic differentiation
    Genetic Resources and Crop Evolution 01/2011; 58(5):657-666. · 1.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: When planning optimal conservation strategies for wild and cultivated types of a plant species, a number of influencing biological and environmental factors should be considered from the outset. In the present study Brassica rapa was used to illustrate this: to develop Scandinavian conservation strategies for wild and cultivated B. rapa, DNA-marker analysis was performed on 15 cultivated and 17 wild accessions of B. rapa plus 8 accessions of the cross compatible B. napus. The B. rapa cultivars were bred in Sweden and Finland in 1944–1997 and the wild B. rapa material was collected from Denmark, Sweden and United Kingdom. The B. napus accessions were bred within the last 20 years in the Scandinavian countries. Results were based on scoring of 131 polymorphic ISSR markers in the total plant material. A Bayesian Markov chain Monte Carlo (MCMC) approach implemented in NewHybrids demonstrated a clear distinction of B. rapa and B. napus individuals except for three individuals that seemed to be backcrosses. The backcrossed hybrids descended from two Swedish populations, one wild and one escaped. The overall pattern of genetic variation and structure in B. rapa showed that cultivated and wild B. rapa accessions formed two almost separated clusters. Geographical origin and breeding history of cultivars were reflected in these genetic relationships. In addition, wild populations from Denmark and Sweden seemed to be closely related, except for a Swedish population, which seemingly was an escaped cultivar. The study point to that many processes, e.g. spontaneous introgression, naturalisation, breeding and agricultural practise affected the genetic structure of wild and cultivated B. rapa populations.
    Genetic Resources and Crop Evolution 01/2009; 56(2):189-200. · 1.59 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Summary Interspecific F1-hybrids may arise in fields with transplastomic oilseed rape where B. rapa occurs as a weed. Spilled seeds, including transplastomic F1-hybrids with B. rapa, may germinate, which creates an opportunity for production of transplastomic BC1 with B. rapa as father (BC1r). Field trials were made with three different proportions of B. napus, B. rapa and F1-hybrids and three different densities. Contrary to most studies on how plant competition affects introgression between oilseed rape and B. rapa, this study focused on offspring produced on F1-hybrids, where the F1-hybrids had oilseed rape as maternal parent. We estimated the BC1r production in all combinations of proportion and density, and found that B. rapa sired from 0.6–7.8% of the offspring. At the proportion with the highest abundance of F1-hybrids the entire paternity was assessed. There was a significant density effect on the production of BC1r but the effect differed among proportions. Both the highest and lowest frequencies of BC1r were obtained at high plant density. Neither the proportion nor density affected the number of BC1r per square-meter significantly. Biomass components decreased significantly from low to intermediate density, whereas a further increase in density only affected the thousand-seed weight significantly. On the basis of the results from the present experiment we conclude that introgression of transgenes from transplastomic oilseed rape to B. rapa seems most likely at current field densities of B. napus, and when B. rapa is an abundant weed.
    Euphytica 09/2006; 150(1):17-25. · 1.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Unlike most studies on hybridisation between oilseed rape and Brassica rapa, this study focused on hybridisation with oilseed rape as the maternal parent. This is a key cross because, assuming that plastids are inherited maternally, F(1)-hybrid production with maternal oilseed rape (B. napus) is the only transgene escape route from transplastomic oilseed rape. We investigated such F(1)-hybrid production in winter oilseed rape co-cultivated with weedy B. rapa at three plant densities each with two proportions of the different species. The paternity of the progeny produced on oilseed rape was assessed, and several fitness parameters were determined in oilseed rape mother plants in order to correlate hybridisation and plant competition. At higher density, the vegetative fitness per mother plant decreased significantly, but the density only affected the frequency of F(1)-hybrids significantly (a decrease) in the treatment with equal proportions of each species. As to the proportions, at higher B. napus frequencies, there were fewer F(1)-hybrids per mother plant and a significant increase in most biomass components. Thus, B. rapa was the stronger competitor in its effect on both the vegetative and reproductive fitness in B. napus, and the hybridisation frequency. In conclusion, the relative frequency of the two species was a more influential parameter than the density. Hybridisation with B. napus as the female will be most likely at current field densities of B. napus and when B. rapa is an abundant weed.
    Heredity 06/2006; 96(5):360-7. · 4.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Controlled reciprocal crosses between B. rapa and F1-hybrids (B. napus (♀)× B. rapa), giving 20 pair-crossings, were made to reveal possible irregularities in chloroplast inheritance during production of BC1s. Despite the close relationship of chloroplasts in B. rapa and B. napus, development of PCR-based molecular markers specific to B. rapa chloroplasts and B. napus chloroplasts was successful. Offspring from each cross were investigated and among these, we found no irregular chloroplast inheritance, since their plastid genotypes in all cases were identical to that of their mother. With a certainty of 95% our data indicate that the probability that chloroplasts are being inherited paternally is less than 0.015. In oilseed rape, pollen-mediated transgene-dispersal poses a well-known risk. Our results support development of transplastomic oilseed rape as an approach to reduce transgene dispersal.
    Molecular Breeding 10/2005; 16(4):271-278. · 3.25 Impact Factor
  • Source
    Lars Landbo, Bente Andersen, Rikke B. Jørgensen
    Hereditas 05/2004; 125(1):89 - 91. · 0.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Wild relatives of genetically engineered crops can acquire transgenic traits such as herbicide resistance via spontaneous crop–wild hybridization. In agricultural weeds, resistance to herbicides is often a beneficial trait, but little is known about possible costs that could affect the persistence of this trait when herbicides are not used. We tested for costs associated with transgenic resistance to glufosinate when introgressed into weedy Brassica rapa. Crosses were made between transgenic B. napus and wild B. rapa from Denmark. F1 progeny were backcrossed to B. rapa and BC1 plants were selected for chromosome numbers similar to B. rapa. Further backcrossing resulted in a BC2 generation that was hemizygous for herbicide resistance. We quantified the reproductive success of 457 BC3 progeny representing six full-sib families raised in growth rooms (plants were pollinated by captive bumblebees). Pollen fertility and seed production of BC3 plants were as great as those of B. rapa raised in the same growth rooms. Segregation for herbicide resistance in BC3 plants was 1:1 overall, but the frequency of resistant progeny was lower than expected in one family and higher than expected in another. There were no significant differences between transgenic and nontransgenic plants in survival or the number of seeds per plant, indicating that costs associated with the transgene are probably negligible. Results from this growth-chamber study suggest that transgenic resistance to glufosinate is capable of introgressing into populations of B. rapa and persisting, even in the absence of selection due to herbicide application.
    Molecular Ecology 12/2003; 8(4):605 - 615. · 6.28 Impact Factor
  • 01/2003; CABI.
  • Source
    01/2003: pages 67-76; Facultas Verlag.
  • Source
    Plant Biotechnology 01/1999; 16:69-71. · 0.94 Impact Factor
  • Acta horticulturae 01/1998; 459:211-217.