97 research outputs found
Genetic polymorphism at RAPD loci in spring turnip rape (Brassica rapa ssp. oleifera)
In this study we analyzed polymorphism at RAPD loci in an outbreeding species, spring turnip rape. The reproducibility of individual RAPD patterns was high when the DNA templates were of equal quality and quantity. It was possible to use both a rapid DNA extraction method and DNA extracted from a combined sample of ten individuals without losing any of the major fragments. When different cultivars were compared for RAPD pattern, most polymorphic loci exhibited differences only in allele frequency. However, we also found fragments which were amplified only from certain cultivars. It was concluded that RAPD markers provide a fast and reliable method for analyzing individuals and cultivars of turnip rape
Estimation of breed contributions to present and future genetic diversity of 44 North Eurasian cattle breeds using core set diversity measures
Extinction of breeds threatens genetic diversity of livestock species. The
need to conserve genetic diversity is widely accepted but involves in
general two questions: (i) is the expected loss of diversity in a set of
breeds within a defined future time horizon large enough to establish a
conservation plan, and if so (ii) which breeds should be prioritised for
such a conservation plan? The present study uses a marker assisted
methodology to address these questions. The methodology combines core set
diversity measures with a stochastic method for the estimation of expected
future diversity and breed marginal diversities. The latter is defined as
the change in the total diversity of all breeds caused by a one unit
decrease in extinction probability of a particular breed. The stochastic
method was validated by means of simulations. A large field data set
consisting of 44 North Eurasian cattle breeds was analysed using simplified
determined extinction probabilities. The results show that the expected loss
of diversity in this set within the next 20 to 50 years is between 1 and
3% of the actual diversity, provided that
the extinction probabilities
which were used are approximately valid. If this loss is to be reduced, it
is sufficient to include those three to five breeds with the highest
marginal diversity in a conservation scheme
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