Genetic Characterization by SSR Markers of a Comprehensive Wine Grape Collection Conserved at Rancho de la Merced (Andalusia, Spain)

Abstract

The IFAPA research center “Rancho de la Merced” (Jerez, Spain) hosts one of the oldest and most diverse grapevine germplasm repositories in Europe, and is aimed at providing feasible solutions to deal with any agronomic trait by exploring its genetic variability and by means of association and Deoxyribonucleic Acid (DNA) editing studies. In this work, we focused on a wine and dual-use grapevine subcollection that consists of 930 accessions. Genetic analysis allowed to identify 521 unique genotypes. After comparing them with several databases, matches were found for 476 genetic profiles while the remaining 45 have not been previously described. Combination with clustering analysis suggested a total pool of 481 Vitis vinifera accessions that included some table cultivars. Several synonymies, homonymies and mislabeling have also been detected. Structure analysis allowed identifying six clusters according to eco-geographic cultivation areas and one additional group including non-vinifera accessions. Diversity analysis pointed out that Spanish Mediterranean varieties are genetically closer to oriental genotypes than to European varieties typical of oceanic and continental climates. The origin of Spanish varieties is discussed in depth considering our data and previous studies. Analysis of molecular variance partition confirmed a well-structured germplasm, although differentiation among groups had a much lower effect on genetic variability than differences within groups, which are strongly related to a very high heterozygosity. A core collection that covers all allele richness is proposed. It is constituted of about 13% of total accessions, and each cluster inferred by structure analysis is represented.

Molecular characterisation of the current cultivars of <i>Vitis vinifera</i> L. in Lanzarote (Canary Islands, Spain) reveals nine individuals which correspond to eight new varieties and two new sports

“…The world populations of Vitis vinifera L. show a low and consistent genetic differentiation (Cretazzo et al, 2022). The results of this study agree with the low and significant values of Fst at the population level (less than 0.10 in practically all populations).…”

“…The Fst and Rst values of are now almost the same, being 0.055 and 0.052 respectively, and both results were significant with a degree of confidence of 0.001. These results are consistent with those obtained by Cretazzo et al (2022) (Summary Table S5b). Summary Table S5b shows that, in terms of its pairwise relationship with other world populations, the population of Lanzarote has the lowest Fst and Rst values for the PI and IC populations, both with good high levels of significance.…”

“…It should be noted that in this study the Rst statistic was used to reinforce or refute the Fst value due to its ability to reject the high and complex mutation rate that characterises microsatellites or SSR, and thereby avoid the overestimation of the genetic differentiation degree due to homoplasy (Balloux and Lugon, 2002). According to these results, we can confirm the singularity of the population of vines of Lanzarote, despite it being historically closely related to the Canary archipelago and the Iberian Peninsula, and despite the Balkans perhaps being of influence It can therefore be concluded that a clear separation exists between the domestication or biodiversity centres of the Iberian Peninsula (and those influenced by it) from the rest (Arroyo-Garcia et al, 2006;Cretazzo et al, 2022). It is worth noting that in Figure 7 all the populations related to the Iberian Peninsula and the Canary Islands are differentiated from the rest of the world populations, which are located on the right-hand side (POP1 subpopulation).…”

“…On the other hand, for the POP2 and IC populations, the lowest values were obtained for both Fst and Rst. These statistics present significant confidence levels (Cretazzo et al, 2022).…”

A Field Collection of Indigenous Grapevines as a Valuable Repository for Applied Research

“…The emergence of intense competition in the international wine market has encouraged the idea of recovering high-quality ancient and indigenous accessions. As a result, a large number of indigenous accessions have been collected from wild and old vineyards, and maintained in the field collections of grapevine-growing countries, including Israel [ 21 ], the USA [ 22 ], Spain [ 23 , 24 ], Italy [ 25 ], and many other countries [ 23 , 26 ]. For example, the United States Department of Agriculture—Agricultural Research Service collections of wild grapevines at the Plant Genetic Resource Unit (Geneva, Switzerland; New York, NY, USA) and the National Clonal Germplasm Repository (Davis, CA, USA) maintain around 5000 accessions as a field collection [ 22 ].…”