Browsing by Author "Varela, Maria Carolina"
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- Characterization of the international network FAIR 202 of provenance and progeny trials of cork oak on multiple sites for further use on forest sustainable management and conservation of genetic resourcesPublication . Varela, Maria Carolina; Tessier, Charles; Ladier, Jean; Dettori, Sandro; Filigheddu, Maria Rosaria; Almeida, Maria Helena; Patrício, Maria Sameiro; Sampaio, TeresaThe international network of provenance and progeny trials was established in 1998 in France, Italy, Portugal, Spain and Tunisia under the EU Commission financed concerted action FAIR 202 benefiting from homogeneous plant raising and standardize experimental design. The trials include 34 provenances that are being characterised using quantitative genetics and molecular genetics to study survival, growth, morphological and physiological traits in relation with geographical origin. France 2008– Provenance were assess using survival, growth (height) and vigour parameters. Provenance PT 23 and PT+ES 25 had the lowest survival rate respectively 79,2% and 77,8% while ES 8, ES 7, MA 31 and PT 19 had 94,4%. In 2008 the mean height at Les Maures was 48.73 cm and the form keeps plagiotropic. Italy- Sardinia, Grighine, 2010 The average mortality was 7%, ranging from 13-14% at the provenance IT LA-VT; IT SI-CT; MO I-1 and 0-2% for FRII, ES 3-V, ES F-PAR, PT IV-03, TU I; TU II. Mean height and trunk DBH over cork were respectively 273cm and 5.1cm. MO I-2, TU II, ES 4-CR are above mean on height (302-309 cm), and the Italian provenances are under mean (237-249cm). The maximum DBH was reached by MO I-2 (6 cm) followed by ES-4 CR and MO III-2 (5.8 cm) and the minimum is at IT PU-BR (3.8 cm), followed by the other Italian provenances (4-4.6cm) and PT V-01 (4.5 cm). Portugal Results from field trials show significant differences among populations on survival, growth and adaptive traits (phenology, water use efficiency - WUE). Mogadouro trial, 2011 -provenance variation was assessed using growth, vigour and survival. The bud burst as adaptive characteristic was observed during 2011-2013. The Moroccan provenances show good adaptive characteristics in terms of growth, vigour and stem form. There was no significant differences (p<0.05) in provenances bud burst. The mean height is not correlated with survival. Italian provenances present lower height but higher survival. The overall mortality is around 26%. The highest growth is being observed in the Moroccan provenances and French ones showed lowest survival. Results from field trials at Italy (continent), Spain and Tunisia are also referred. Genotype by environment interaction (G x E) is discussed. Due to the large variability of responses between cork oak provenances we emphasise the importance to use these results when considering the seed origin aiming for large scale planting programs for adaptation, cork quality, pest and diseases susceptibility and for conservation of genetic resources, Progeny trials provide key information for genetic improvement programmes on estimates of breeding values on economic characteristics such as cork quality and an approach on inbreeding problems. Perspectives Used in synergy the results from provenance and progeny trials are likely to provide insights for balancing the conflicting objectives such as maximising selection intensity while maintaining variation. Taking into consideration that the cork from the second striping made 3-4 years after the first gives information about the quality liable to be used on selection for afforestation guide lines we enhance the need of concerted criteria on debarking season and procedures. The results from these trials will contribute to the knowledge on genetic variation and are a privileged living material to study climate change effects and adaptation to biotic and abiotic factors and for sustainable management of this long living species.
- Characterization of the international network FAIR 202 of provenance and progeny trials of cork oak on multiple sites for further use on forest sustainable management and conservation of genetic resources.Publication . Varela, Maria Carolina; Tessier, Charles; Ladier, Jean; Dettori, Sandro; Filigheddu, Maria Rosaria; Bellarosa, Rosanna; Vessella, Federico; Almeida, Maria Helena; Sampaio, Teresa; Patrício, Maria SameiroThe international network of provenance and progeny trials was established in 1998 benefiting from homogeneous plant raising and standardize experimental design. The trials include 34 provenances that are being characterised by several teams. France 2008. Provenance PT 23 and PT+ES 25 had the lowest survival rate. In 2008 the mean height was 48.73 cm and the form keeps plagiotropic. Italy- Sardinia, 2010 - The average mortality was 7%. Mean height and trunk DBH over cork were respectively 273 and 5.1 cm. MO I-2, TU II, ES 4-CR are above mean on height (302-309 cm), and the Italian provenances are under mean (237-249cm). Italy- Roccarespampani, Lazio- The mortality is about 45% and it is the only plantation site where the French provenance FR3 has a growth above mean. Portugal. Results show significant differences among populations on survival and growth. The Moroccan provenances show good adaptive characteristics in terms of growth, vigour and stem form. Italian provenances present lower height but higher survival. The overall mortality is around 26%. The highest growth is being observed in the Moroccan provenances and French ones showed lowest survival. Provenances and plantation sites are characterised for rainfall regime. The provenances Morocco MA27 and Tunisia TU33 that are from sites of high rainfall are among the best on growth at sites of considerable more xerothermic climate. If persistent at older age these results indicate that fast adaptation of cork oak populations to cope with climate changes leading to drier and warmer conditions seems possible.
- O contributo da origem e das práticas silvícolas na sustentabilidade dos montados de sobroPublication . Almeida, Maria Helena; Nunes, Ana Margarida; Correia, António H.; Patrício, Maria Sameiro; Carvalho, Maria Augusta; Varela, Maria Carolina; Monteiro, Maria do LoretoConsiderando que, num contexto global de exigência crescente das sociedades e de implementação de políticas de gestão sustentável dos recursos naturais, cabe às entidades e agentes ligados ao sector participar de uma forma activa numa adequada aplicação e inovação das práticas existentes, os autores pretendem dar um contributo para o melhoramento dos montados de sobro e para a obtenção de um maior rendimento em cortiça. Nesse sentido entendem que os esforços desenvolvidos para a identificação de populações de sobreiro mais adaptadas devem ser completados com a aplicação de práticas silvícolas que conduzam a um maior rendimento em cortiça. Assim, foram implementados cortes de formação nas primeiras idades em ensaios genéticos de sobreiro existentes no nosso País, pertencentes a uma rede internacional, que cobrem no seu conjunto toda a área de distribuição da espécie, com o objectivo de obter fustes direitos e cilíndricos em pelo menos 3 a 4 m do tronco, contribuindo de uma forma efectiva e directa para uma maior valorização da prancha de cortiça e consequentemente proporcionar uma mais-valia no rendimento do proprietário florestal. A variação observada quer ao nível das populações quer das descendências nestes ensaios é indicativo que não é indiferente a escolha da população a utilizar nas acções de repovoamento, assim como na implementação de um programa de melhoramento, apontando também para a necessidade de seleccionar os indivíduos dentro das populações. A experiência adquirida relativamente à poda de formação aconselha que esta operação seja efectuada num período de crescimento activo das plantas para garantir uma cicatrização rápida dos tecidos e uma menor rebentação nas zonas dos cortes.
- O contributo da origem e das práticas silvícolas na sustentabilidade dos montados de sobroPublication . Almeida, Maria Helena; Nunes, Ana Margarida; Correia, António H.; Patrício, Maria Sameiro; Carvalho, Maria Augusta; Varela, Maria Carolina; Monteiro, Maria do LoretoConsiderando que, num contexto global de exigência crescente das sociedades e de implementação de políticas de gestão sustentável dos recursos naturais, cabe às entidades e agentes ligados ao sector participar de uma forma activa numa adequada aplicação e inovação das práticas existentes, os autores pretendem dar um contributo para o melhoramento dos montados de sobro e para a obtenção de um maior rendimento em cortiça. Nesse sentido entendem que os esforços desenvolvidos para a identificação de populações de sobreiro mais adaptadas devem ser completados com a aplicação de práticas silvícolas que conduzam a um maior rendimento em cortiça. Assim, foram implementados cortes de formação nas primeiras idades em ensaios genéticos de sobreiro existentes no nosso País, pertencentes a uma rede internacional, que cobrem no seu conjunto toda a área de distribuição da espécie, com o objectivo de obter fustes direitos e cilíndricos em pelo menos 3 a 4 m do tronco, contribuindo de uma forma efectiva e directa para uma maior valorização da prancha de cortiça e consequentemente proporcionar uma mais-valia no rendimento do proprietário florestal. A variação observada quer ao nível das populações quer das descendências nestes ensaios é indicativo que não é indiferente a escolha da população a utilizar nas acções de repovoamento, assim como na implementação de um programa de melhoramento, apontando também para a necessidade de seleccionar os indivíduos dentro das populações. A experiência adquirida relativamente à poda de formação aconselha que esta operação seja efectuada num período de crescimento activo das plantas para garantir uma cicatrização rápida dos tecidos e uma menor rebentação nas zonas dos cortes.
- Évaluation préliminaire des essais de provenances de chêne-liège et perspectives de recherchePublication . Varela, Maria Carolina; Almeida, Maria Helena; Sampaio, Teresa; Patrício, Maria Sameiro; Dettori, Sandro; Filigheddu, Maria Rosaria; Sirca, C.; Belarosa, R.; Vessella, Federico; Simeone, M.; Iglesias, S.; Aranda, Ismael; Khouja, M.; Khaldi, A.Le réseau international des essais de provenance et de descendance de chêne-liège (établie dans le cadre du projet Action Concertée FAIR CT 95-202 “European network for the evaluation of genetic resources of cork oak for appropriate use in breeding and gene conservation strategies” financé par l’Union Européenne) constitue un matériel vivant unique pour la recherche, qu’elle soit appliquée, ou fondamental, sur l’espèce. Les essais génétiques ont été réalisés sur une base méthodologique harmonisée au niveau des plants utilisés (tous les plants ont été élevées dans une même pépinière au Portugal) et sur terrain un même dispositif expérimental a été suivi. En 1997/98, 13 essais de provenances ont été établis. Ceux ayant réussi sont situés en Espagne (2), France (1), Italie (3), Portugal (3) et Tunisie (1). Concernent les essais de descendances il existe 4 des 5 initiales - Espagne (1), Portugal (2) et Tunisie (1). Dans ce travail nous présentons quelques résultats du comportement des provenances à travers des caractéristiques adaptatifs tels que la survie, l’efficacité d’utilisation de l’eau et des études de génomique. Nous avons procédé à la comparaison de chaque provenance dans les essais - niveau horizontal- et à la comparaison de chaque provenance entre les essais - niveau vertical afin de discuter la plasticité phénotypique et l’interaction génotype X environnement. Les données disponibles pour hauteur en 2006 montre des différences de comportement entre provenances et entre les essais. Par exemple, les provenances du Maroc montre une croissance supérieure dans l’essai plus au Sud au Portugal et aussi dans un essai en Espagne. Pour l’essai de Sardaigne les meilleures provenances sont de Tunisie et d’Espagne. A la fin on discute sur les avantages des essais comme matériel vivant dénominateur commun pour une recherche avancée, multidisciplinaire, synergétique, transnational et concertée. Les perspectives pour la recherche sur les grands thèmes tels que la gestion durable du chêne-liège, notamment la sélection, amélioration génétique, adaptation aux changements globaux, fluxes génétiques, problèmes phytosanitaires, qualité du liège en liaison avec la respective génomique sont adressées.
- L’origine du matériel de reproduction et les pratiques sylvicoles: outils pour la durabilité des subéraiesPublication . Almeida, Maria Helena; Patrício, Maria Sameiro; Gaspar, Maria J.; Varela, Maria Carolina; Rodrigues, Ana Paula; Correia, António H.; Monteiro, Maria do LoretoDans le contexte actuel de l’exigence croissante de la société et de l’implémentation des politiques de gestion durable des ressources naturelles et face aux risques des changements climatiques, il incombe aux entités et agents liés au secteur une participation active à l’application adéquate et à l'innovation des pratiques forestières. Les auteurs prétendent apporter une contribution à l'amélioration des forêts de chênes liège afin d’améliorer leur rendement en liège. Dans ce contexte, les efforts développés pour identifier les populations de chêne-liège les plus adaptées devraient être complétés par l'application des pratiques sylvicoles qui permettront l’augmentation de ce rendement. Des tailles de formation ont été réalisées sur des jeunes essais génétiques de chêne liège âgés de 11 ans, installés au Portugal (nombre de sujets, date tailles, etc). L'objectif principal de ces tailles est d’obtenir un fût rectiligne d'au moins 3 à 4 m afin de valoriser les planches de liège et par conséquent fournir une valeur ajoutée aux revenus du propriétaire forestier. Les variations observées, que ce soit au niveau des populations (donner ces variations) ou au niveau des descendances (donner ces variations) révèlent l’importance du choix des populations à utiliser dans le reboisement et dans les programmes d'amélioration génétique. Cela met en évidence la nécessité de sélectionner les individus au sein des populations. Donner plus de résultats chiffrés au résumé
- Provenance behavior in the cork-oak International network trials fair 202Publication . Varela, Maria Carolina; Sampaio, Teresa; Filigheddu, Maria Rosaria; Zucca, G.M.; Patrício, Maria Sameiro; Almeida, Maria Helena; Ramirez-Valiente, José Alberto; Aranda, Ismael; Tessier, C.; Ladier, Jean; Dettori, SandroThe international network of provenance trials in cork-oak was established as a result of the EU Concerted Action FAIR 202, 1995-2000. 34 provenances were selected in the natural range of cork oak and trials were established in 1996/97 in France, Italy, Portugal, Tunisia and Spain. This study compares the behavior of provenances in the trials of Grighini (Sardinia), Monte Fava and Quinta da Nogueira (Portugal), Monfrague (Spain), Les Maures (France) and Tebabe (Tunisia). Observations on total height (Ht) and diameter at beast height (DBH) are used to compare and assess adaptation within sites and among sites. Climate at the provenance site seed collection and at trials sites is used to characterize the behavior of provenances. The results reveal that the provenances, ES 5 (1063 mm), IT16 (910 mm), IT12 (937 mm), 937, TU32 (948 mm), FR2 (958 mm, FR1 (963 mm, MA31 (970 mm), ES8 (993 mm) are able to adapt and show good growth under conditions of decrease of total annual rainfall and strong decrease in case of TU33 (1610mm), MA27 (1280 mm). On the other hand provenances coming from sites of low precipitation not always show relevant performance in sites of higher precipitation as IT14 (448 mm), ES10 (455 mm), MA29 (479 mm). These results are discussed in the impact climate change (CC) may have in adaptation and evolution of cork oak. Our results show that cork oak will not face serious threats if drought increases in the Mediterranean region, since some populations are showing capable to cope successfully with decrease of total precipitation. The ongoing results from the cork-oak international network trials FAIR 202 show the importance of this line of research and the need to establish harmonized criteria on data collection to enhance the comparability. As cork quality is a key issue on cork-oak economic sustainability it is critical to establish harmonized criteria in cork harvesting for further studies to compare cork quality with special reference for the assessment of the genetic control of cork production and heritability.
- Quercus suber geographic variation: preliminary results of the Iberian Península provenance trialsPublication . Almeida, Maria Helena; Aranda, Ismael; Chambel, Maria Regina; Fachada, Ivone; Gil, Luís; Lourenço, Maria João; Monteiro, Maria do Loreto; Nunes, Ana Margarida; Patrício, Maria Sameiro; Pereira, João Santos; Ramirez-Valiente, José Alberto; Rocha, Sara; Sampaio, Teresa; Varela, Maria CarolinaCork oak (Quercus suber L.) has a great social and ecological importance in the Iberian Peninsula. Yet, a large proportion of cork oak stands is old and natural regeneration is often problematic. During the last decade large areas were reforested with this species in the context of the Common Agriculture Policy (CAP) both in Portugal and Spain. Survival rates were often low due to inappropriate nursery and installation techniques, as well as to the use of unsuitable genetic material. In fact, the cork oak adaptability to environmental conditions is poorly understood; moreover climate change scenarios foreseen enhanced water deficits in the Mediterranean region. In order to allocate the most adequate seed sources to each set of climatic conditions in future afforestation activities and considering that an important source of variation in the characteristics related with adaptability may be at the provenance level, we evaluated inter-provenance variability and phenotypic plasticity for growth, survival, morphological structure and drought tolerance five years after plantation, in four test sites located across the Iberian Peninsula and covering a wide range of ecological conditions. Such trials are part of a multi-locality provenance test belonging to a Network that was bring up by Concerted action. European network for the evaluation of genetic resources of cork oak for appropriate use in breeding and gene conservation strategies. where 35 cork oak populations covering all the natural distribution area are represented.