84 research outputs found
Analysis of the contribution of Mesoamerican and Andean gene pools to European common bean (Phaseolus vulgaris L.) germplasm and strategies to establish a core collection.
No full textCommon bean (Phaseolus vulgaris L.)
was introduced in Europe from both Mesoamerican
and Andean centres of origin. In this study, a
collection including 544 accessions from all European
regions showed that the Andean phaseolin
types ‘T’ (45.6%) and ‘C’ (30.7%) prevailed over
the Mesoamerican ones ‘S’ (23.7%), and accessions
with cuboid seed shape (34.9%), maroon coat darker
colour seed (44.3%), uniform seed colour (69.6%)
were the most frequent. European accessions with
phaseolin ‘S’ showed a significantly larger average seed size compared to those from America in the
same phaseolin class while those presenting ‘T’ and
‘C’ phaseolin did not. This suggests that, during
crop expansion in Europe, sampling or selection
favoured the large-seeded races within the Mesoamerican
‘S’ gene pool or, possibly, introgression
from Andean germplasm did occur. A core collection
was developed using sampling approaches
based on the information available in the genebank
databases and on phaseolin patterns. Four sampling
strategies were used: simple random sampling, and
three random-stratified samplings, by logarithm of
frequency of accessions by country, by European
region, and by phaseolin pattern, respectively. Two
sampling strategies resulted in core collections
significantly different for phaseolin electrophoretic
patterns from the whole collection. Stratification by
phaseolin patterns increased the frequency of ‘S’
types (‘C’ type = 33%, ‘T’ type = 5.7% and ‘S’
type = 31.3%). The core collections were validated
using seven seed characters, and no significant
difference was observed in all strategies. This first
developed European bean core collection will help
to assess the contribution of the two American gene
pools to the European germplasm and their relative
importance for breeding purposes
Beans in Europe: Origin and Structure of the European Landraces of Phaseolus vulgaris L.
No full textThis study focuses on the expansion of Phaseolus vulgaris in Europe. The pathways of distribution of beans into and across Europe were very complex, with several introductions from the New World that were combined with direct exchanges between European and other Mediterranean countries. We have analyzed here six chloroplast microsatellite (cpSSR) loci and two unlinked nuclear loci (for phaseolin types and Pv-shatterproof1). We have assessed the genetic structure and level of diversity of a large collection of European landraces of P. vulgaris (307) in comparison to 94 genotypes from the Americas that are representative of the Andean and Mesoamerican gene pools. First, we show that most of the European common bean landraces (67%) are of Andean origin, and that there are no strong differences across European regions for the proportions of the Andean and Mesoamerican gene pools. Moreover, cytoplasmic diversity is evenly distributed across European regions. Secondly, the cytoplasmic bottleneck that was due to the introduction of P. vulgaris into the Old World was very weak or nearly absent. This is in contrast to evidence from nuclear analyses that have suggested a bottleneck of greater intensity. Finally, we estimate that a relatively high proportion of the European bean germplasm (about 44%) was derived from hybridization between the Andean and Mesoamerican gene pools. Moreover, although hybrids are present everywhere in Europe, they show an uneven distribution, with high frequencies in central Europe, and low frequencies in Spain and Italy. On the basis of these data, we suggest that the entire European continent and not only some of the countries therein can be regarded as a secondary diversification center for P. vulgaris. Finally, we outline the relevance of these inter-gene pool hybrids for plant breeding
Measuring the Local Economic Impact of Cooperatives
No full textThe ability to measure the economic importance of cooperatives to communities is not purely an academic question. Policy makers, cooperative organizations, and community development practitioners are increasingly asking for such information. The most commonly used methodology is input-output analysis. The limitations of input-output analysis when applied to cooperatives have not yet been comprehensively explained in the literature, although they significantly affect the application of the model as well as the interpretation of results. We discuss five issues that need to be addressed when using input-output models and suggest additional analysis that should be completed to gain an accurate assessment of the local economic impact of cooperatives.cooperatives, economic impact, community development, input-output models, Agribusiness,
DNA SEQUENCE POLYMORPHISM DISCRIMINATED MESOAMERICANAND ANDEAN GENEPOOLS IN COMMON BEAN (PHASEOLUS VULGARIS L.)
No full textIntroduction bottleneck and the contribute of Mesoamerican and Andean gene pools to common bean (Phaseolus vulgaris L.) diversity in Europe.
No full textCommon bean (Phaseolus vulgaris L., 2n = 2x = 22) is the most important edible food legume for direct human consumption in Europe and in the world as it represents a valuable source of proteins, vitamins, fibres, and minerals. Genetic and archaeological studies have shown that domestication of P. vulgaris was originated and domesticated in the New World and has two major gene pools, the Andean and the Mesoamerican, based on their centers of origin in South and Central America, respectively. After the first voyages of Columbus (1492) common bean was brought to Europe but historical and linguistic sources provide little evidence of the introduction and expansion of common bean in Europe. In common bean a large number of nuclear microsatellite markers (nuSSRs) have been already developed and mapped that show relatively high levels of polymorphism, thus providing an attractive choice for describing population structure. However, to the best of our knowledge, population studies of the European common bean, using nuSSRs, so far have been performed with only a small number of landraces or a small number of samples from a few geographic regions. In the present study, we used thirteen highly polymorphic nuSSRs to assess
the genetic structure and level of diversity of a large collection of European landraces (256
individuals), in comparison with a representative American sample (89 individuals). Moreover, to
obtain a detailed picture and to elucidate the effects of bottleneck of introduction and selection for
adaptation during the expansion of common bean over the whole Europe, we also complemented
the nuSSRs analysis by information provided by a Bayesian analysis implemented in
STRUCTURE. Here, we present and discuss the role that inter-gene pool hybridization have had in
shaping the genetic structure of the European bean landraces. The implication for evolution and the
advantages for common bean breeding are also discussed
DNA sequence polymorphism discriminated mesoamerican and andean genepools in common bean (Phaseolus Vulgaris L.
No full textCommon bean (Phaseolus vulgaris L.) is the most important edible food legume in the world.
It is an important source of calories, proteins, dietary fibres, minerals and vitamins for millions of
people in both developing and developed countries.
Common bean was originated and domesticated in the New World and has two major gene
pools, the Andean and the Mesoamerican, based on their centers of origin in South and Central
America, respectively. The existence of Andean and Mesoamerican gene pools is supported by
molecular marker analyses (seed storage protein, isozymes, RFLPs, RAPDs, AFLPs, and SSRs).
These can be complemented by DNA sequence data that provide a complete and unambiguous
genotype of all specific genomic regions.
In this study we assessed the frequency of SNPs in a fragment of P. vulgaris DNA localized
on the B8 linkage group. This fragment was obtained from genomic DNA. We conducted a
sequence analysis of 80 European domesticated landraces, belonging to a European core collection,
147 American wild and domesticated common bean genotypes, that had been previously assigned to
the Andean or Mesoamerican gene pools using phaseolin patterns and as a control, 10 genotypes of
P. coccineus, P. lunatus, P. acutifolius and P. polyanthus.
Including indels, sequence lengths was 393 bp. In P. vulgaris one 46 bp indel and 4 SNPs
distinguished unequivocally the Mesoamerican and the Andean gene pools. The population
structure identified in this study is generally consistent with the current hierarchical scheme of gene
pools. This DNA sequence displays 5 polymorphic markers that discriminate very clearly the two
gene pools of P. vulgaris
- …
