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

Smallanthus sonchifolius is a periennal herb originally cultivated in South America and now grown in several other countries. Recently, greater attention has been focused on this plant due to its agronomical, nutritional and pharmacological characteristics. In this paper the application of RAPDs and AFLPs for the analysis of genetic diversity in a group of 5 Smallanthus sonchifolius landraces is presented. Both methods proceed through the direct analysis of DNA, and their results were compared with the total phenolic content of each landrace and its morphological traits. Using 61 RAPD primers, 85 informative bands were identified, corresponding to 28.7% of polymorphism. In comparison, only six selected AFLP primer pairs produced 84 informative bands, with a similar percentage of polymorphism (23.4%). RAPD and AFLP markers were analyzed separately. Total phenolic content varied twofold among the five landraces analysed, ranging from 3,494 to 6,849 mg/g. Each type of molecular marker resolved two main groups that included the same genotypes, but with different within-group relationships among genotypes. The two groups are consistent with some phenotypic characters but they do not reflect faithfully their geographical origin. Most notably, the two groups comprise landraces with higher and lower total phenolic content, respectively. Dendrograms based on the two molecular data sets graphically depicted the ability of both methods to differentiate all the cultivars studied. Data obtained suggest that the two molecular markers applied are useful to investigate intra-specific genetic variability in Smallanthus sonchifolius, and predict well the total phenolic content of each landrace.

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