The aim of this work is to analyse the temporal change of genetic diversity in Italian durum wheat germplasm. The germplasm deployed in this study (158 accessions), belonging to 5 different historical classes, was characterised for its microsatellite and gliadin markers. The level of genetic diversity (He), based on gliadin and SSR markers results – on\ud
average – greater in indigenous landraces present in\ud
Italy before 1915, with the exception of pure line\ud
material which had been selected from landraces\ud
(showing highest level of heterozigosity for gliadin\ud
markers). Genotypes obtained from crosses or mutagenesis\ud
(referring to the 1950–1960 period) along\ud
with those resulting from crosses between CIMMYT\ud
lines and old materials (1970s and beyond) were also\ud
genetically more diverse. Forty-nine percent of\ud
indigenous landraces were genetically heterogeneous.\ud
Nine out of 53 landrace accessions were able to\ud
capture 4 different SSR private alleles. It is speculated\ud
that the reduction of allele richness is an indicator\ud
of the genetic erosion of the pre-breeding\ud
germplasm and it is pointed out that the implementation\ud
of appropriate methods of genetic conservation\ud
of this germplasm is a priority for breeding and food\ud
safet
The aims of this paper were to study the genetic diversity within and among 6
Tuber taxa, the phylogenetic relationships and the spatial distribution of truffles from the
Basilicata region (southern Italy). Molecular analyses, using the internal transcribed spacer
region, microsatellites, minisatellites and random amplified polymorphic loci revealed the
highest expected intra-specific heterozygosity (He=0.30) in T. aestivum, followed by that
of T. mesentericum (He=0.22). T. borchii (He=0.17), T. magnatum (He=0.16), T. aestivum
fo. uncinatum (He=0.12) and T. brumale fo. moschatum (He=0.09) showed a lower average
heterozygosity. The whole set of markers were demonstrated to be useful in clearly differentiating
Tuber taxa, separating them in two distinct groups and in five sub-clusters,
each corresponding to one single taxon. The first cluster (T. borchii, T. magnatum and
T. brumale fo. moschatum) was more differentiated than the second one (T. aestivum,
T. aestivum fo. uncinatum and T. mesentericum). T. brumale fo. moschatum was the most
differentiated Tuber taxon. It was more related to the white truffles (the closely related
T. borchii and T. magnatum) than to the remaining related black truffles T. aestivum and
T. mesentericum. The amount of Tuber species richness was higher over the western side of
Basilicata, in cold Lauretum and in Castanetum phytoclimatic Pavari’s zones. A spatial
genetic structure was detected for T. aestivum, as shown by the significant correlation
between geographic and genetic distances (rs=0.32; P<0.0001). Integration of molecular
and geographic diversity patterns can allow the selection of sites for Tuber and Tuberrelated
biodiversity conservation
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.