The investigation on the genetic diversity of grapevine germplasm is crucial for a more efficient use of grapevine genetic resources in light of changing environmental conditions. Here, we used simple sequence repeats (SSRs) coupled with single nucleotide polymorphism (SNP) markers to disclose grapevine genetic diversity of a collection of Apulian minor/neglected genotypes. Their relationships with national or international cultivars were also examined. Genetic diversity was investigated using 10 SSR markers and 1,178 SNPs generated by genotyping by sequencing (GBS). Based on the SSR data, the 128 genotypes were classified into six main genetic clusters. Twenty-four putative cases of synonymy and 2 of misnamings were detected. Ten “unknown” autochthonous genotypes did not show high similarity to Apulian, national, or international varieties. We took advantage of available GBS-derived SNP data points for only forty genotypes to better investigate the genetic distance among them, identify private SNP alleles, and divergent loci putatively under selection. Based on SNP alleles, two interesting gene pools of minor/neglected Apulian samples were identified. Genetic divergence was investigated by FST and allowed the detection of loci capable of differentiating the gene pools. Overall, this work emphasizes the need for recovering the untapped genetic variability that characterizes minor/neglected grapevine Apulian genotypes and the requirement to preserve and use more efficiently grapevine genetic resources in breeding programs.
Wine and fermenting musts are grape products widely consumed worldwide. Since the presence of mycotoxin-producing fungi may greatly compromise their quality characteristics and safety, there is an increasing need for relatively rapid “user friendly” quantitative assays to detect fungal contamination both in grapes delivered to wineries and in final products. Although other fungi are most frequently involved in grape deterioration, secondary infections by Penicillium spp. are quite common, especially in cool areas with high humidity and in wines obtained by partially dried grapes. In this work, a single-tube nested real-time PCR approach—successfully applied to hazelnut and peanut allergen detection—was tested for the first time to trace Penicillium spp. in musts and wines. The method consisted of two sets of primers specifically designed to target the β-tubulin gene, to be simultaneously applied with the aim of lowering the detection limit of conventional real-time PCR. The assay was able to detect up to 1 fg of Penicillium DNA. As confirmation, patulin content of representative samples was determined. Most of analyzed wines/musts returned contaminated results at >50 ppb and a 76% accordance with molecular assay was observed. Although further large-scale trials are needed, these results encourage the use of the newly developed method in the pre-screening of fresh and processed grapes for the presence of Penicillium DNA before the evaluation of related toxins.
The development of a robust Agrobacterium-mediated transformation protocol for a recalcitrant species like durum wheat requires the identification and optimization of factors affecting T-DNA delivery and plant regeneration. The purpose of this research was to compare the behavior of diverse durum wheat genotypes during in vitro culture and Agrobacterium tumefaciens-mediated transformation, using immature embryos as explants. Apart from plant genotype, two of the main influencing factors for a successful genetic transformation have been examined here, i.e., auxin source (Dicamba and 2,4-D) and duration of the pre-culture period (one, seven and 21 days). The addition of Dicamba to the media in combination with seven days pre-cultivation resulted in a general enhancement of T-DNA delivery for most of the analyzed cultivars, as revealed by β-glucuronidase (GUS) histochemical assay. Although all genotypes were able to produce calli, significant differences were detected in regeneration and transformation efficiencies, since only two (Karalis and Neolatino) out of 14 cultivars produced fertile transgenic plants. The estimated transformation efficiencies were 6.25% and 1.66% for Karalis and Neolatino, respectively, and χ2 analysis revealed the stable integration and segregation of the gus transgene in T1 and T2 progenies. This research has demonstrated that, among the influencing factors, genotype and auxin type play the most important role in the success of durum wheat transformation.