Lalla Hasna Zinelabidine

Identification by SNP Analysis of a Major Role for Cayetana Blanca in the Genetic Network of Iberian Peninsula Grapevine Varieties

Cayetana Blanca is a grapevine variety widely distributed in the Iberian Peninsula (Spain and Portugal). Its numerous synonyms and its presence in northern Africa point to a long history of cultivation. The goal here was to identify the genetic relationships of Cayetana Blanca with other Iberian and Mediterranean cultivars using a panel of SNP markers. A total of 243 single nucleotide polymorphisms (SNPs) and four chloroplast microsatellite loci allowed for identifying synonyms and trio (parents and offspring) and duo (parent-offspring) relationships. Six trios including Cayetana Blanca as a parent were found and supported by very high LODs. Five of the trios had the variety Alfrocheiro Preto as the other parent and gave rise to cultivars used in Portugal: Cornifesto, Camarate, Mouratón, Malvasia Preta, and Periquita. The Spanish cultivar Jaén Tinto is confirmed to be an offspring of Cayetana Blanca and Listán Prieto. Additionally, synonyms and duos were detected that, in some cases, were not anticipated. The parents of Cayetana Blanca remain unknown, while the geographical origin of Cayetana Blanca could be a border region between Portugal and Spain. Results show that this cultivar has had a relevant impact in the viticulture of that area. As in other European regions, viticulture in the Iberian Peninsula is also marked by the impact of certain varieties that have worked as progenitors of many present cultivars. The results also show the interconnection between Portuguese and Spanish viticulture. Finally, the study demonstrates that SNP is a powerful tool for parentage inference in grapevine.

Genetic diversity and parentage of Tunisian wild and cultivated grapevines (Vitis vinifera L.) as revealed by single nucleotide polymorphism (SNP) markers

Based on 261 single nucleotide polymorphism (SNP) markers, we analyzed 57 grapevine genotypes, consisting of 29 wild grapevines (Vitis vinifera subsp. sylvestris) prospected from the northwest part of Tunisia and 28 cultivated accessions (V. vinifera subsp. vinifera) maintained in the repository of the Arid Land Institute of Medenine (Tunisia). Pair-wise multilocus comparison with the ICVV SNP database allowed the identification of 13 cultivated genotypes, including ten synonymous groups with known Mediterranean or international varieties, three cases of color sports, and two misnomers. Genotypic analysis showed a high level of genetic diversity for both wild and cultivated groups. Multivariate and structure analyses clearly differentiated wild from cultivated grapevines and showed high average posterior probabilities of assignment to their group of origin. The clustering results largely supported the perceived classification and reflect that most of the present Tunisian cultivated varieties do not derive directly from the local wild populations but could correspond to materials introduced from different locations during historical times. Parentage analysis allowed the determination of the genetic origin of four Tunisian cultivars, “Garai”, “Jerbi” (from Kerkennah), “Mahdoui”, and “Reine de Vignes faux”, and showed that “Heptakilo” and “Planta Fina”, two old and widely distributed varieties in the Mediterranean basin, had an important role in the origin of Tunisian grapevines. The present study demonstrates the efficacy of SNP makers for germplasm characterization and genetic studies in grapevine.

Variabilité des caractères morphologiques des populations naturelles de Medicago truncatula Gaertn. au Maroc

Abstract The objective of this work is to study the genetic variability between natural populations of Medicago truncatula in Morocco by using morphological characters. We have studied the phenotypic diversity in nine wild populations of M. truncatula collected from different region. We have analysed twelve morphological characters related to vegetative and reproductive development of plants which have been cultivated in homogenous conditions. The variance analysis have exhibited significant differences between populations for all morphological characters. This indicates an important inter—population variability. The principal component analysis of all populations shows two major groups. The diversity was found to be structured on the basis of ecological factors as rainfall and altitude. The populations coming from zones of middle-to-high altitude with middle rainfall have shown vigorous plants with premature flowing and fructification. In the opposite, populations coming from zones of weak-to-middle altitude with strong rainfall are characterized by a weak vegetative development with late flowering and fructification.