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Medenine, Tunisia

Peiro R.,Polytechnic University of Valencia | Gammoudi N.,Arid Lands Institute IRA | Yuste A.,Polytechnic University of Valencia | Olmos A.,Instituto Valenciano Of Investigaciones Agrarias Ivia | Gisbert C.,Polytechnic University of Valencia
Spanish Journal of Agricultural Research | Year: 2015

The conservation of old grapevine varieties is important since they are adapted to specific climate conditions and may carry genes interesting to breeders. As virus infection is common in grapevine varieties, the use of virus free materials is of great importance. In this work, we used somatic embryogenesis for the sanitation of GLRaV-1 and GLRaV-3 viruses that were found after analyzing the putative presence of the five most common, economically important grape viruses by real-time multiplex RT-PCR in the old cultivar “Grumet Negre”. Unopened and opened inflorescences, fecundated ovaries, and, also, mature seeds were used as starting explants. Explants were cultured on plates with two embryogenesis induction media (Nitsch & McCown Woody plant medium) that contained the growth regulator thidiazuron and differed in their salt and vitamin compositions. One half of each kind of explant was cut prior to being cultured. After five months of culture, embryos had only developed from seeds that were cut previous to sowing. To the best of our knowledge, this is the first time that mature seeds have been used for inducing embryogenesis in grape. A total of 42% of the embryos transferred to tubes for germination regenerated into normal plantlets. The absence of both the GLRaV-1 and GLRaV-3 viruses in all regenerated plants was confirmed by real-time uniplex RT-PCR. So, this protocol can be used for sanitation and also for micropropagation. © 2015 INIA. Source

Sanchez-Torres P.,Instituto Valenciano Of Investigaciones Agrarias Ivia | Raigon M.D.,Universidad Politecnica de Ingenieria | Gammoudi N.,Arid Lands Institute IRA | Gisbert C.,Polytechnic University of Valencia
Fruits | Year: 2016

Introduction. Interest in grafting onto rootstocks resistant to soil-borne pathogens has risen since the phasing-out of methyl bromide, an efficient soil disinfectant. In this study, we have evaluated the putative effect of rootstock-scion combinations on pepper fruit nutritional quality in relation to grafting, an effect that is sometimes overlooked. Materials and methods. As the scions, we used two representative sweet pepper cultivars, 'Almuden' and 'Coyote', and as rootstocks 'Foc' and 'Charlot', both resistant to Phytophthora capsici and Meloidogyne incognita. Dry matter, soluble solids, proteins, phenolics, and vitamin C content, as well as eight minerals (P, K, Ca, Mg, Na, Fe, Cu, and Zn) were measured in fruits from non-grafted, self-grafted, and grafted plants. Results and discussion. Differences in the fruit composition were found, depending on the genotype, rootstock, or rootstock-scion combination. The main effects were as follows. Higher values of °Brix, phenolics, P, Mg, and Na were found in the fruit of 'Coyote' whereas the vitamin C and Fe levels were higher in 'Almuden' fruit. The dry matter, protein, and K concentrations were higher in the fruit from grafted plants with respect to the values from non-grafted plants, especially in the fruit from plants grafted onto 'Charlot' and 'Foc' rootstocks (increases of 11.8%, 17.6%, and 9.6%, respectively; when average values of the four combinations of these rootstocks). Fruit from 'Almuden' and 'Coyote' plants grafted onto the rootstock 'Foc' had lower °Brix values (about one degree less than the control) and lower values of phenolics were also obtained when used this rootstock (14.4% less than for the control). On the other hand, the P concentration was higher in the fruit of 'Coyote' grafted onto 'Charlot' (17.2% higher than for the control). This combination also exhibited the highest fruit K concentration (226.70 mg 100 g-1 fresh weight). Conclusion. From a nutritional point of view it is important to evaluate and select the best rootstock-scion combinations: in our assay, this was 'Charlot'-'Coyote' the fruit of which showed the highest °Brix and K, P, and protein concentrations. © 2016 Cirad/EDP Sciences. Source

Yahia Y.,Arid Lands Institute IRA | Hannachi H.,Arid Lands Institute IRA | Monforte A.J.,Polytechnic University of Valencia | Cockram J.,UK National Institute of Agricultural Botany | And 3 more authors.
Plant Genetic Resources: Characterisation and Utilisation | Year: 2014

Faba bean (Vicia faba L.) is one of the most important legumes in the world. Little is known about the genetic resources of faba bean in Southern Tunisia. In the present study, genetic diversity within Tunisian faba bean germplasms was investigated using 16 simple sequence repeat markers. In total, 50 alleles were detected. The number of alleles per marker ranged from 2 to 6, with an average of 3. Genetic diversity and polymorphism information content values averaged, respectively, 0.43 (range 0.34-0.51) and 0.36 (range 0.28-0.43). The mean heterozygosity value was 0.27. A model-based structure analysis based on neighbour-joining tree and factorial correspondence analysis revealed the presence of two subpopulations, consistent with the clustering based on genetic distance (GD). The overall F is value was 0.36, indicating the importance of selfing in these populations. Analysis of molecular variance revealed that the within-population genetic variance component was much higher than the between-population or between-subpopulation variance component. The genetic relationships based on Nei's GD revealed that AGD (Aguadulce) and SAG (Super Aguadulce) and TF1 and TF2 (Tafartassa-Gafsa) were the most closely related populations. Assessment of genetic variation within faba bean populations will be informative for the conservation of germplasms and the implementation of effective breeding programmes in Tunisia. © 2014 NIAB. Source

Yahia Y.,Arid Lands Institute IRA | Hannachi H.,Institute Superieur Des Science Appliquees Et Of La Technology Of Gabes | Ferchichi A.,Arid Lands Institute IRA
Acta Botanica Gallica | Year: 2014

The genetic diversity of 13 Tunisian faba bean (Vicia faba L.) accessions, and the commercial variety "Aguadulce", were studied using simple sequence repeats (SSRs) and random amplified polymorphic DNA (RAPD) markers. In comparison to RAPD markers, SSRs showed a higher level of polymorphism and greater information content, as assessed by the expected heterozygosity. One hundred and fourteen bands were amplified using six SSR primer combinations and 376 bands were observed using four RAPD primers. The percentages of polymorphic fragments were 100% and 60.63% for SSR and RAPD markers, respectively. The polymorphism information content, gene diversity and population differentiation test were 0.370, 0.490 and 0.746, respectively, for SSR markers and 0.319, 0.406 and 0.775 for RAPD markers. The correlation coefficients of similarity based on the Mantel test were statistically significant for the both marker systems used, but were higher for SSR data than for RAPD. Dendrogram topologies, conducted separately on polymorphic RAPD and SSR markers, showed minor differences in the grouping of accessions. The dendrogram based on combined RAPD and SSR data sets identified clustering of accessions according to their geographic diffusion. Collectively, these results will aid Tunisian faba bean germplasm management, conservation and breeding. © 2014 Société botanique de France. Source

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