Physiological traits associated with wheat yield potential and performance under water-stress in a mediterranean environment

Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (Δ13C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha−1 under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between Δ13C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions

Ecotypic differentiation and phenotypic plasticity combine to enhance the invasiveness of the most widespread daisy in Chile, Leontodon saxatilis

Dispersal and reproductive traits of successful plant invaders are expected to undergo strong selection during biological invasions. Numerous Asteraceae are invasive and display dimorphic fruits within a single flower head, resulting in differential dispersal pathways - wind-dispersed fruits vs. nondispersing fruits. We explored ecotypic differentiation and phenotypic plasticity of seed output and fruit dimorphisms in exotic Chilean and native Spanish populations of Leontodon saxatilis subsp. rothii. We collected flower heads from populations in Spain and Chile along a rainfall gradient. Seeds from all populations were planted in reciprocal transplant trials in Spain and Chile to explore their performance in the native and invasive range. We scored plant biomass, reproductive investment and fruit dimorphism. We observed strong plasticity, where plants grown in the invasive range had much greater biomass, flower head size and seed output, with a higher proportion of wind-dispersed fruits, than those grown in the native range. We also observed a significant ecotype effect, where the exotic populations displayed higher proportions of wind-dispersed fruits than native populations. Together, these patterns reflect a combination of phenotypic plasticity and ecotypic differentiation, indicating that Leontodon saxatilis has probably increased propagule pressure and dispersal distances in its invasive range to enhance its invasiveness

Flora of the mediterranean basin in the chilean espinales: evidence of colonisation

In Chile’s Mediterranean region, over 18% of plant species are alien. This is particularly noteworthy in some agrosilvopastoral systems such as the espinales, which are functionally very similar to the Spanish dehesas and are of great ecological and socioeconomic interest. In the present paper we analyse Chile’s non-native flora, considering three scales of analysis: national, regional (the central region, presenting a Mediterranean climate) and at community level (the espinales within the central region). We compare this flora with that recorded in areas of the Iberian Peninsula with similar lithological and geomorphological characteristics, and land use. We discuss possible mechanisms that might have been operating in the floristic colonisation from the Mediterranean Basin to Chile’s Mediterranean region

Bases ecológicas para implementar un sistema de uso silvopastoral en la región patagónica de Aysén, Chile

Resumen de Tesis Doctoral, Departamento de Ecología. Facultad de Biología, Universidad Complutense de Madrid, Fecha de lectura: 18/09/2012, Directores: José Manuel de Miguel Garcinuño y Alejandro del Pozo Lira.La tesis pretende identificar las bases científicas para la implementación de un sistema de uso silvopastoral con arbolado nativo en la región patagónica de Aysén, Chile. Este sistema se plantea como una alternativa al modelo actual de gestión del territorio que considera el uso ganadero y el forestal de forma independiente, tanto en sus objetivos como en las zonas de actuación. La hipótesis general es que la presencia de árboles mejora la producción ganadera y el mantenimiento de valores naturalísticos en la región, respecto a zonas desprovistas de árboles. Para ello se examinan dos escenarios experimentales complementarios: un gradiente de cobertura arbolada, desde bosque denso a pradera abierta, y cuatro zonas de contacto entre bosque denso y pradera sin arbolado. Los resultados muestran que en un paisaje silvopastoral donde coexistan praderas abiertas y zonas de arbolado, valores intermedios de cobertura maximizan la producción herbácea y mantienen niveles aceptables de calidad de los pastizales, a la vez que permiten la persistencia de especies herbáceas nativas asociadas al bosque original. El estudio caracteriza también la respuesta de los pastizales al abandono ganadero reciente

Fungal literature records database of the sub-Antarctic Region of Aysén, Chile

Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEpu

Fungal literature records database of the sub Antarctic Region of Aysén, Chile

To this day, merely 8% of all estimated fungi species are documented and, in certain regions, its biodiversity is practically unknown. Inside the Fungi Kingdom, macrofungi and lichens assume a critical part in the ecosystem functionality and have a historical connection to mankind's social, clinical and nutritious uses. Despite their importance, the diversity of these groups has been widely overlooked in the sub-Antarctic Region of Chile, a crucial area in the study of climate change due to its extraordinary biodiversity and its proximity to Antarctica. Few studies regarding both groups have been conducted in this sub-Antarctic Region and the data are still scarce and inaccessible, as these are only published in specialised journals, unreachable to local communities.Chile's Innovation for Competitiveness Fund (FIC) provided funding for both SIB-Aysén (BIP 30346481-0) and the Open Laboratory for Sub-Antarctic Sciences (BIP 40000521-0) initiatives.Peer reviewe

Native and non-native herbaceous species dependence on tree cover in grazing systems from northern Chilean Patagonia

Grazing systems that combine grasslands and woodlands represent changes in tree cover that influences herbaceous vegetation and may threaten the native forest flora. We studied these influences in Chilean Patagonia where recent colonization resulted in the fragmentation of the lenga (Nothofagus pumilio) forests leading to a mosaic-type landscape. The herbaceous vegetation, transmitted photosynthetically active radiation (PAR) and other forest structure characteristics were sampled in 15 (20 m × 20 m) plots differing in tree cover for two years, while considering the relative position (below or beyond) of tree crowns. Herbaceous species were classified as forest, non-forest, and forest indifferent species according to their preference, rejection or indifference to the forest environment. Species richness decreased with increasing PAR but this was dependent on the response of non-natives. Species composition varied gradually from open grasslands to dense forests, according to transmitted PAR values. Native species were associated to either forests or open areas, but the number of native species did not vary along the tree cover gradient (beyond tree crowns) or even decreased (below tree crowns). Non-native species dominated in the open grasslands and beyond tree crowns and its richness increased with transmitted PAR. The occurrence of grasslands and dense forests within this grazing system is shown to promote higher species richness. Management will consider that dense forest patches are necessary for maintaining a high diversity of native species, since isolated trees or low wooded areas do not guarantee the persistence of all native species associated to the original forests

Physiological traits associated with wheat yield potential and performance under water-stress in a mediterranean environment

Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (Δ13C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha−1 under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between Δ13C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions

Phenolic composition and bioactivity of Ribes magellanicum fruits from southern Patagonia

Eight Ribes magellanicum collections from three different places in southern Patagonia were compared for content of different groups of phenolics, antioxidant capacity and inhibition of enzymes related to metabolic syndrome (α-amylase, α-glucosidase and pancreatic lipase). The sample with the highest antioxidant capacity was assessed for glutathione (GSH) synthesis stimulation in human gastric adenocarcinoma (AGS) cells. The chemical profile was determined by high performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) and the main phenolics were quantified. The samples from Navarino Island and Reserva Nacional Magallanes showed higher content of anthocyanins and caffeoylquinic acid, with better activity towards α-glucosidase and antioxidant capacity. A sample from Omora (Navarino Island), significantly increased intracellular GSH content in AGS cells. Some 70 compounds were identified in the fruit extracts by HPLC-MS/MS. The glucoside and rutinoside from delphinidin and cyanidin and 3-caffeoylquinic acid were the main compounds. Different chemical profiles were found according to the collection places

Variability of herbaceous productivity along Nothofagus pumilio forest-open grassland boundaries in northern Chilean Patagonia

In order to develop a general model of aboveground net primary production (ANPP) of herbaceous communities in grazing systems that combine forested and open grasslands in temperate areas, biomass production and a set of biotic and abiotic variables were measured at four adjacent forest and grassland sites in Chile’s northern Patagonia for two consecutive growing seasons. At each site, one transect of 80 m long (40 m in open grassland and 40 m in forest) × 10 m wide was established. ANPP was significantly higher in open grasslands but no gradual change in biomass production was observed from inside the forest towards the open grassland. In open grasslands ANPP was spatially uniform but highly variable between years of contrasting weather conditions, whereas in forests it was more spatially heterogeneous and less variable over time. ANPP was highly correlated with cattle consumption. Structural equation models developed for the whole system confirm that ANPP was driven mainly by photosynthetically active radiation (PAR) and available nitrogen. However, we found important differences between forests and the adjacent open grasslands. In forests ANPP was enhanced by positive feedbacks between the amount of transmitted PAR through the canopy and soil nutrient input via cattle dung deposition. In open grasslands nitrogen availability appeared to be the main limiting factor but also influenced by weather conditions (dryer or wetter years). The coexistence of forests and grasslands patches, with different susceptibility of ANPP to meteorological and soil nutrient availability, highlights the importance of implementing an integrated silvopastoral system with lenga (Nothofagus pumilio [Poepp. & Endl.] Krasser) in northern Patagonia