18 research outputs found
Nuclear and chloroplast microsatellite diversity in Phaseolus vulgaris L. from Sardinia (Italy).
Studies of the level and the structure of
the genetic diversity of local varieties of Phaseolus
vulgaris are of fundamental importance, both for the
management of genetic resources and to improve our understanding of the pathways of dissemination and
the evolution of this species in Europe. We have here
characterized 73 local bean populations from Sardinia
(Italy) using seed traits and molecular markers
(phaseolins, nuSSRs and cpSSRs). American landraces
and commercial varieties were also included for
comparison. We see that: (a) the Sardinian material is
distinct from the commercial varieties considered; (b)
the variation in the seed traits is high and it mostly
occurs among populations (95%); (c) compared to the
American sample and the commercial varieties, the
Sardinian collection has a low level of diversity; (d)
the majority ([95%) of the Sardinian individuals
belong to the Andean gene pool; (e) the Sardinian
material shows a strong genetic structure, both for
cpSSRs and nuSSRs; (f) the nuSSRs and cpSSRs
concur in differentiating between gene pools, but a
lack of congruence between nuclear and chloroplast
has been observed within gene pools; and (g) there
are three putative hybrids between the Andean and
Mesoamerican gene pools. Despite the relatively low
level of diversity, which is probably due to a strong
founder effect, the Sardinian landraces are worth
being conserved and studied further because of their
distinctiveness and because hybridization within and
between the gene pools could generate variation that
will be useful for breeding