Propagación de Lecanophora heterophylla : especie nativa con potencial ornamental

En este trabajo se presentan estudios de germinación y propagación in vitro de L. heterophylla, nativa con potencial ornamental. Se evaluó el efecto del momento y lugar de recolección sobre la germinación. Se recolectaron semillas en plena floración y al final de la misma, en dos localidades de la provincia de Mendoza: Gualtallary y Chacras de Coria. Las pruebas de germinación se realizaron en estufa a 20 °C. Las semillas provenientes de Gualtallary germinaron en mayor proporción que las de Chacras de Coria: en ambas localidades la máxima germinación se obtuvo en la recolección de plena floración. Para establecer un protocolo de micropropagación se realizaron dos ensayos de introducción y uno de multiplicación. En la introducción se evaluó el medio de cultivo MS entero o ½ de macronutrientes, en combinación con BA y AIB. En la multiplicación se evaluaron los medios MS ½ o ¼ de macronutrientes con 20 o 40 g.L-1 de sacarosa. No se encontraron diferencias en la sobrevivencia, el BA incrementó significativamente la proliferación de brotes. El mejor medio de multiplicación fue MS ¼ adicionado de 20 g.L-1 de sacarosa.

Micropropagación de la enredadera nativa Mutisia subspinosa Cav.

La especie nativa Mutisia subspinosa es una enredadera perenne, resistente a heladas, con hermosas flores anaranjadas que presenta gran interés como ornamental. En trabajos previos de propagación a través de semillas o estacas se obtuvieron escasos resultados, lo que justificó el uso de la micropropagación. Para el establecimiento in vitro se utilizó el medio de Murashige Skoog (MS) diluido a la mitad. Se evaluó la adición de 6-bencilaminopurina (BAP) sola o en combinación con thidiazurón (TDZ) y un testigo sin hormonas. En la etapa de multiplicación se utilizó el mismo medio basal y se probaron dos auxinas: los ácidos indol butírico (AIB) y naftalén acético (ANA), además del uso de carbón activado. La composición del medio de cultivo más adecuada para el establecimiento fue la del testigo, mientras que para la multiplicación los mejores resultados se obtuvieron con la adición de 4 μmoles.L-1 de ANA. El agregado de 1 g.L-1 de carbón activado al medio de cultivo con 2,7 μmoles.L-1 mejoró la tasa de multiplicación y el enraizamiento.

Revisión del género Salix (Salicaceae) en la Provincia de Mendoza, Argentina

Se realiza una revisión del género Salix en la Provincia de Mendoza a fin de contribuir al conocimiento de su flora fanerogámica. Son reconocidas siete especies, una subespecie, dos formas y tres híbridos. Entre ellos existe una especie y una variedad nativa. Cada taxa es identificada a través de una clave, descripta, documentada e ilustrada.

Micropropagación de Glandularia, género nativo con potencial ornamental

En este trabajo se estableció un protocolo de propagación in vitro de tres especies nativas del género Glandularia: G. peruviana, G. sp. y G. laciniata. Para el establecimiento in vitro se evaluó el medio de Murashige Skoog (MS) con macro y micronutrientes diluidos a la mitad adicionado con 0,05 μM de bencilaminopurina (BAP) sola o en combinación con 0,1 μM thiadiazuron (TDZ) y un testigo sin reguladores del crecimiento. En la etapa de multiplicación se evaluó el medio de cultivo MS diluido a la ½ ó ¼ y adicionado de 20 ó 40 gr.L-1 de sacarosa. Es posible establecer y micropropagar estas especies en medios de cultivo sencillos. El medio más eficiente para el establecimiento fue aquel sin reguladores, mientras que el más adecuado para la multiplicación fue MS ½ adicionado de 20 gr.L-1 de sacarosa, en el cual la tasa de multiplicación cada 30 días fue de 6 en G. sp. y G. peruviana y 4 para G. laciniata.

(Table 1) UK research stations, refuges and major depots between 1944 and 2010

Globally, areas categorically known to be free of human visitation are rare, but still exist in Antarctica. Such areas may be among the most pristine locations remaining on Earth and, therefore, be valuable as baselines for future comparisons with localities impacted by human activities, and as sites preserved for scientific research using increasingly sophisticated future technologies. Nevertheless, unvisited areas are becoming increasingly rare as the human footprint expands in Antarctica. Therefore, an understanding of historical and contemporary levels of visitation at locations across Antarctica is essential to a) estimate likely cumulative environmental impact, b) identify regions that may have been impacted by non-native species introductions, and c) inform the future designation of protected areas under the Antarctic Treaty System. Currently, records of Antarctic tourist visits exist, but little detailed information is readily available on the spatial and temporal distribution of national governmental programme activities in Antarctica. Here we describe methods to fulfil this need. Using information within field reports and archive and science databases pertaining to the activities of the United Kingdom as an illustration, we describe the history and trends in its operational footprint in the Antarctic Peninsula since c. 1944. Based on this illustration, we suggest that these methodologies could be applied productively more generally.

Plant communities and soil chemistry of shrub-steppe and pine savannah grasslands in southern British Columbia, Canada

Habitat fragmentation alters the edges of remnant habitat patches. We examined changes in the plant community and soil in relation to distance from edge and edge type for shrub-steppe and pine savannah grasslands in southern British Columbia, Canada. Community composition showed significant nonlinear relationships with distance-to-edge more frequently at paved roads and fruit crops than at dirt roads or control sites (i.e., in the interior of grassland patches), with changes typically extending 25-30 m. More exotic species and fewer native species were found near edges, and edges showed decreased cryptogam cover and increased bare ground, especially near paved roads. The soil factors that best predicted compositional changes were soil pH and Cu/Mn at paved roads, soil pH and nitrogen at fruit crops, and soil resistance at dirt roads. Variation partitioning suggested that both direct (e.g., propagule pressure) and indirect (environmental change) factors mediated edge-related community changes, and provided evidence that nonlinear responses at developed edges were not due to natural gradients. Given the range of grassland patch sizes in this region (many patches 1-100 ha), the edge effects we observed represent a considerable loss of "core" habitat, which must be accounted for in conservation planning and site restoration.

Molecular tools to improve chestnut management: El Bierzo as a case study

The European chestnut (Castanea sativa Mill.) is a multipurpose species that has been widely cultivated around the Mediterranean basin since ancient times. New varieties were brought to the Iberian Peninsula during the Roman Empire, which coexist since then with native populations that survived the last glaciation. The relevance of chestnut cultivation has being steadily growing since the Middle Ages, until the rural decline of the past century put a stop to this trend. Forest fires and diseases were also major factors. Chestnut cultivation is gaining momentum again due to its economic (wood, fruits) and ecologic relevance, and represents currently an important asset in many rural areas of Europe. In this Thesis we apply different molecular tools to help improve current management strategies. For this study we have chosen El Bierzo (Castile and Leon, NW Spain), which has a centenary tradition of chestnut cultivation and management, and also presents several unique features from a genetic perspective (next paragraph). Moreover, its nuts are widely appreciated in Spain and abroad for their organoleptic properties. We have focused our experimental work on two major problems faced by breeders and the industry: the lack of a fine-grained genetic characterization and the need for new strategies to control blight disease. To characterize with sufficient detail the genetic diversity and structure of El Bierzo orchards, we analyzed DNA from 169 trees grafted for nut production covering the entire region. We also analyzed 62 nuts from all traditional varieties. El Bierzo constitutes an outstanding scenario to study chestnut genetics and the influence of human management because: (i) it is located at one extreme of the distribution area; (ii) it is a major glacial refuge for the native species; (iii) it has a long tradition of human management (since Roman times, at least); and (iv) its geographical setting ensures an unusual degree of genetic isolation. Thirteen microsatellite markers provided enough informativeness and discrimination power to genotype at the individual level. Together with an unexpected level of genetic variability, we found evidence of genetic structure, with three major gene pools giving rise to the current population. High levels of genetic differentiation between groups supported this organization. Interestingly, genetic structure does not match with spatial boundaries, suggesting that the exchange of material and cultivation practices have strongly influenced natural gene flow. The microsatellite markers selected for this study were also used to classify a set of 62 samples belonging to all traditional varieties. We identified several cases of synonymies and homonymies, evidencing the need to substitute traditional classification systems with new tools for genetic profiling. Management and conservation strategies should also benefit from these tools. The avenue of high-throughput sequencing technologies, combined with the development of bioinformatics tools, have paved the way to study transcriptomes without the need for a reference genome. We took advantage of RNA sequencing and de novo assembly tools to determine the transcriptional landscape of chestnut in response to blight disease. In addition, we have selected a set of candidate genes with high potential for developing resistant varieties via genetic engineering. Our results evidenced a deep transcriptional reprogramming upon fungal infection. The plant hormones ET and JA appear to orchestrate the defensive response. Interestingly, our results also suggest a role for auxins in modulating such response. Many transcription factors were identified in this work that interact with promoters of genes involved in disease resistance. Among these genes, we have conducted a functional characterization of a two major thaumatin-like proteins (TLP) that belongs to the PR5 family. Two genes encoding chestnut cotyledon TLPs have been previously characterized, termed CsTL1 and CsTL2. We substantiate here their protective role against blight disease for the first time, including in silico, in vitro and in vivo evidence. The synergy between TLPs and other antifungal proteins, particularly endo-p-1,3-glucanases, bolsters their interest for future control strategies based on biotechnological approaches.

Desenvolvimento floral e do óvulo e aspectos da reprodução em Aechmea sp. e Vriesea sp. (Bromeliaceae)

A utilização de Bromélias tem sido crescente no mercado de plantas onamentais, por outro lado, muitas espécies encontram-se ameaçadas, grande parte pelos impactos humanos no ambiente. Aechmea correia-araujoi E. Pereira & Moutinho, Aechmea gamossepala Wittm, Vriesea ensiformis (Vell.) Beer e Vriesea saundersii (Carrière) E. Morren ex Mez, espécies nativas da Mata Atlântica brasileira, têm sido alvo de extrativismo. Informações básicas sobre a espécie são essenciais para subsidiar a condução de programas de conservação e melhoramento genético, que aliados a ferramentas biotecnológicas permitem a incorporação de estratégias inovadoras aos métodos de melhoramento. Neste sentido, o objetivo do presente trabalho foi descrever essas espécies, quanto à micromorfologia floral, aspectos reprodutivos envolvidos no processo de polinização, desenvolvimento floral e deesenvolvimento gametofítico, como mecanismo de preservação e produção comercial. A caracterização morfológica e anatômica das flores das espécies de Aechmea e Vriesea contribuiu para a compreensão do processo reprodutivo. As espécies apresentam grãos de pólen com alta capacidade reprodutiva, viabilidade polínica superior a 93%, germinação in vitro maior que 80% e o estigma apresenta-se receptivo da antese ao final do dia. A ontogênese floral de A. correia-araujoi é centrípeta, os primórdios desenvolvem-se na ordem, sépala, pétala, androceu e gineceu. O apêndice petalar é formado na fase final do desenvolvimento. O primórdio de óvulo tem origem placentária e caráter trizonal, o óvulo é anátropo, bitegumentado e crassinucelado. O meristema floral de A. gamosepala se desenvolve de forma centrípeta, de forma unidirecional reversa. O estigma diferencia-se na fase inicial do desenvolvimento e os apêndices petalares, na fase final. O óvulo é anátropo, crassinucelado, bitegumentado, tétrade linear, megásporo calazal funcional, desenvolvimento tipo monospórico e Polygonum. As anteras são bitecas, tetraesporangiadas, com tapete secretor. Botões florais de 8,7 - 13,0 mm são indicados no estudo de embriogênese a partir de micrósporo. As alterações celulares e o padrão de distribuição de pectinas e AGPs foram caracterizadas por análise citoquímica com azul de toluidina, KI e DAPI e imunocitoquímica por imunofluorescência com os anticorpos para RNA, pectinas esterificadas (JIM7), não esterificadas (JIM5) e AGPs (LM2, LM6, MAC207, JIM13, JIM14) e analisadas por microscopia de fluorescência. Foram caracterizados padrões de distribuição espaço-temporal de pectinas e AGP que podem ser utilizados como marcadores de desenvolvimento gametofítico masculino. As observações feitas nesse trabalho fornecem dados sobre aspectos reprodutivos das espécies que podem ser utilizados em programas de melhoramento genético, conservação e desenvolvimento de haploides

Sustainability in the Upper Colorado River Basin: A Struggle Between Water Resource Use and Remnants of the Natural Ecosystem

This study evaluated whether development of the Colorado River system has exceeded sustainability by comparing the trends in water use in the Colorado River. Two sustainable areas were identified in the upper basin and one in the lower-- the mainstream Colorado River, Green and Yampa rivers, and the Little Colorado River. These areas are also high priority recovery areas for four endangered fishes and protected by critical habitat provisions of the ESA. Unfortunately, the endangered fishes are declining because of habitat destruction and non-native species. If increasing water demand causes the fishes to go extinct the few sustainable areas will be lost. It will take careful management of the endangered fishes and water users to ensure these areas are maintained.

How can an invasive grass affect fire behavior in a tropical savanna? A community and individual plant level approach

Some invasive grasses have been reported to change fire behavior in invaded plant communities. Urochloa brizantha is an aggressive invasive grass in the Brazilian Cerrado, an ecosystem where fire is a common disturbance. We investigated the effects of U. brizantha on fire behavior in an open Cerrado physiognomy in Central Brazil. Using experimental burnings we compared fire behavior at both the community and the individual plant level in invaded (UJ) and non-invaded (NJ) areas burned in July. We also assessed the effect of fire season in invaded areas by comparing July (UJ) and October (UO) burnings. We evaluated the following variables: fuel load, fuel moisture, combustion efficiency, maximum fire temperature, flame height, and fire intensity. Additionally, we evaluated the temperatures reached under invasive and native grass tussocks in both seasons. Fuel load, combustion efficiency, and fire intensity were higher in NJ than in UJ, whilst flame height showed the opposite trend. Fuel amount and fire intensity were higher in October than in July. At the individual plant level, U. brizantha moisture was higher than that of native species, however, temperatures reaching ≥600 °C at ground level were more frequent under U. brizantha tussocks than under native grasses. At the community level, the invasive grass modified fire behavior towards lower intensity, lower burning efficiency, and higher flame height. These results provide essential information for the planning of prescribed burnings in invaded Cerrado areas.

Ecological restoration across the Mediterranean Basin as viewed by practitioners

Restoration efforts in the Mediterranean Basin have been changing from a silvicultural to an ecological restoration approach. Yet, to what extent the projects are guided by ecological restoration principles remains largely unknown. To analyse this issue, we built an on-line survey addressed to restoration practitioners. We analysed 36 restoration projects, mostly from drylands (86%). The projects used mainly soil from local sources. The need to comply with legislation was more important as a restoration motive for European Union (EU) than for non-EU countries, while public opinion and health had a greater importance in the latter. Non-EU countries relied more on non-native plant species than EU countries, thus deviating from ecological restoration guidelines. Nursery-grown plants used were mostly of local or regional provenance, whilst seeds were mostly of national provenance. Unexpected restoration results (e.g. inadequate biodiversity) were reported for 50% of the projects and restoration success was never evaluated in 22%. Long term evaluation (> 6 years) was only performed in 31% of cases, and based primarily on plant diversity and cover. The use of non-native species and species of exogenous provenances may: i) entail the loss of local genetic and functional trait diversity, critical to cope with drought, particularly under the predicted climate change scenarios, and ii) lead to unexpected competition with native species and/or negatively impact local biotic interactions. Absent or inappropriate monitoring may prevent the understanding of restoration trajectories, precluding adaptive management strategies, often crucial to create functional ecosystems able to provide ecosystem services. The overview of ecological restoration projects in the Mediterranean Basin revealed high variability among practices and highlighted the need for improved scientific assistance and information exchange, greater use of native species of local provenance, and more long-term monitoring and evaluation, including functional and ecosystem services' indicators, to improve and spread the practice of ecological restoration.

Colección ex situ de plantas vivas de especies nativas del orden Zingiberales del Sur del Lago de Maracaibo, Venezuela

The loss of biological diversity in the Southern Part of the Lago de Maracaibo, Venezuela, due to cattle rising, has caused the extinction of 97 % of the original the Zingiberales order for purpose of study and conservation, because of the importance of this subject in the tropical floriculture (cut flowers, foliage and landscaping). The use of the biological diversity and the new native species flora could promote the efficient and sustainable use of the natural resources of the Southern Part of the Lago de Maracaibo. For that reason, it was collected 18 samples among varieties and species which passed the nursery stage, and then they were transplanted in the field after three months, besides, it was accounted the humidity and light conditions they had in their natural ecosystem; as a result plants showed favorable adaptability indicators.

Pinos autóctonos y conservación de bosques en Andalucía

La evolución del arbolado en la Península Ibérica pasó por numerosos episodios que le condujeron a una situación grave de deforestación. Tras varios intentos de reforestación en épocas distintas, finalmente la apuesta definitiva se produciría con la creación del Patrimonio Forestal del Estado y el Plan Nacional de Repoblación Forestal de España de 1939. La sustitución del PFE por el ICONA en 1971, supuso un nuevo contexto, en el que se puso en duda tanto la actuación repobladora, como las especies utilizadas, principalmente del género Pinus. Este trabajo trata de poner en valor la información que aportan distintas corrientes científicas, la botánica, la biogeografía, paleobotánica y los datos de otros estudios realizados en numerosos yacimientos arqueológicos en Andalucía, especialmente en la zona oriental. Estos trabajos ponen de manifiesto la presencia de especies del género Pinus en distintos periodos geológicos, con avances y retrocesos del binomio Pinus-Quercus, durante períodos más o menos extensos. La repoblación forestal supuso un avance a una de esas situaciones, que dió como resultado el marco de nuevas intervenciones de manejo del bosque por la Administración Andaluza, siendo las exigencias de conservación prioritarias en la gestión de los espacios forestales, muchos de ellos declarados Espacios Protegidos. Se trata pues, de poner en valor aquellas actuaciones que dieron lugar a la nueva situación en la que se apuesta por la conservación y en la que juegan un papel importante la genética y la productividad de las especies utilizadas en las intervenciones forestales.