Marginal Grapevine Germplasm from Apulia (Southern Italy) Represents an Unexplored Source of Genetic Diversity

Monica Marilena Miazzi,Pasquale Venerito,Pierfederico La Notte,Costantino Pirolo,Cinzia Montemurro,Vincenzo Roseti,Francesca Taranto,Valentina Di Rienzo,Vito Nicola Savino,Nunzio D’Agostino,Paola Ruffa,Vincenzo Fucilli

doi:10.3390/agronomy10040563

Abstract

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.

Highlights

IntroductionVinifera, 2n = 2x = 38) domestication occurred in the Near East and Caucasian area during the Neolithic
Grapevine (Vitis vinifera subsp. vinifera, 2n = 2x = 38) domestication occurred in the Near East and Caucasian area during the Neolithic from wild forms (Vitis vinifera L. subsp.sylvestris (Gmelin) Hegi) [1]
We investigated the genetic diversity of a panel of minor/neglected Apulian genotypes collected from marginal areas of the region and previously characterized for ampelographic and morphological traits [45], with the aim to emphasize the need for recovering the untapped genetic variability that often characterize neglected germplasm

Summary

Introduction

Vinifera, 2n = 2x = 38) domestication occurred in the Near East and Caucasian area during the Neolithic Grapevine was spread by humans in the Middle East and Central. Three processes had a considerable impact on the development of cultivated grapevines: sexual reproduction, vegetative propagation, and somatic mutations. Plants are usually maintained and multiplied by vegetative propagation (asexual). The occurrence of somatic mutations in one clone and not in others might eventually lead to plants of the same cultivar showing a different phenotype. This is referred to as clonal variation [3]

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Discussion

Conclusion