Biological control of intolerant hardwood competition: Silvicultural efficacy of Chondrostereum purpureum and worker productivity in conifer plantations

The vigorous vegetative reproduction of intolerant deciduous competition limits the efficacy of mechanical release operations in young softwood plantations. Applying bioherbicides such as the fungus Chondrostereum purpureum (Pers. ex Fr.) Pouzar could improve the effectiveness of release by reducing stump sprouting while gaining public acceptance. A field experiment was conducted in Québec (Canada) in two white spruce (Picea glauca [Moench] Voss) plantations invaded by intolerant hardwoods. This study compared four-year response of traditional mechanical release and mechanical release with an application of C. purpureum under the commercial formulation Myco-Tech™. The general objective of the project was to measure the silvicultural efficacy and worker productivity related to applying C. purpureum to control intolerant hardwoods in young white spruce plantations.     

Determination of Phenolic Compounds in Three Edible Ripening Stages of Yellow Guava (Psidium cattleianum Sabine) after Acidic Hydrolysis by LC-MS/MS

Plant Foods for Human Nutrition - Yellow guava (Psidium cattleianum Sabine) has received considerable attention in the last years because of their high content in bioactive compounds with potential...     

Reproducible genomic DNA preparation from diverse crop species for molecular genetic applications

Background

Several high-throughput molecular genetic analyses rely on high-quality genomic DNA. Copurification of other molecules can negatively impact the functionality of plant DNA preparations employed in these procedures. Isolating DNA from agronomically important crops, such as sugarcane, rice, citrus, potato and tomato is a challenge due to the presence of high fiber, polysaccharides, or secondary metabolites. We present a simplified, rapid and reproducible SDS-based method that provides high-quality and -quantity of DNA from small amounts of leaf tissue, as required by the emerging biotechnology and molecular genetic applications.

Results

We developed the TENS-CO method as a simplified SDS-based isolation procedure with sequential steps of purification to remove polysaccharides and polyphenols using 2-mercaptoethanol and potassium acetate, chloroform partitioning, and sodium acetate/ethanol precipitation to yield high-quantity and -quality DNA consistently from small amounts of tissue (0.15 g) for different plant species. The method is simplified and rapid in terms of requiring minimal manipulation, smaller extraction volume, reduced homogenization time (20 s) and DNA precipitation (one precipitation for 1 h). The method has been demonstrated to accelerate screening of large amounts of plant tissues from species that are rich in polysaccharides and secondary metabolites for Southern blot analysis of reporter gene overexpressing lines, pathogen detection by quantitative PCR, and genotyping of disease-resistant plants using marker-assisted selection.

Conclusion

To facilitate molecular genetic studies in major agronomical crops, we have developed the TENS-CO method as a simple, rapid, reproducible and scalable protocol enabling efficient and robust isolation of high-quality and -quantity DNA from small amounts of tissue from sugarcane, rice, citrus, potato, and tomato, thereby reducing significantly the time and resources used for DNA isolation.

     

The need for clear and comparable terminology in benthic ecology. Part I. Ecological concepts

• 1. This note highlights problems with the definition and use of terminology in the field of benthic ecology, and compares the French classification with the UK and EUNIS classifications. These problems stem partly from language‐related difficulties, particularly the translation from English to French and vice versa, but also from the incoherence of certain typologies used in EU classifications and Directives.
• 2. The boundaries used by legislators and developers take neither ecological constraints nor environmental parameters into account. Most often, these boundaries are set using distances or depths that have no basis in the distribution of benthic species.
• 3. Retaining the definition of ‘étage’ that was proposed by Pérès (1961) is recommended, and the following classification hierarchy is proposed: supralittoral, mediolittoral, infralittoral with an upper littoral fringe, circalittoral with distinct coastal circalittoral and open circalittoral zones, bathyal, abyssal and hadal.

Copyright © 2007 John Wiley & Sons, Ltd.     

Estimates of fishing gear loss rates at a global scale: A literature review and meta‐analysis

Abandoned, lost or otherwise discarded fishing gear (ALDFG) represents a significant, yet ultimately unknown amount of global marine debris, with serious environmental and socioeconomic impacts. This study reviews 68 publications from 1975 to 2017 that contain quantitative information about fishing gear losses. Gear loss estimates reported by the studies ranged widely, with all net studies reviewed reporting annual gear loss rates from 0% to 79.8%, all trap studies reporting gear loss rates from 0% to 88%, and all line studies reporting gear loss rates from 0.1% to 79.2%. Information obtained from this review was used to perform a meta‐analysis that provides the first synthetic, statistically robust estimates of global fishing gear losses. The meta‐analysis estimates global fishing gear losses for different major gear types. We estimate that 5.7% of all fishing nets, 8.6% of all traps, and 29% of all lines are lost around the world each year. Furthermore, we identified key gear characteristics, operational aspects and environmental contexts that influence gear loss. These estimates can be used to support sustainable fisheries development through informing risk assessments for fisheries and monitoring and assessment efforts to reduce gear losses.     

Thermal preference,tolerance, and thermal aerobic scope in clownfish Amphiprion ocellaris (Cuvier, 1830) predict its aquaculture potential across tropical regions

The clownfish Amphiprion ocellaris is widely distributed in the coral reef ecosystems of tropical and subtropical regions of the West Indo Pacific, an area that hosts economically valuable species, and, thus, a suitable candidate for warm water aquaculture. This study determined the preferred temperature, critical threshold limits, represented by critical thermal maximum and critical thermal minimum, thermal window width, and aerobic metabolic scope of A. ocellaris clownfish acclimated to 20, 23, 26, 29, 32, and 35 °C. A positive response (P < 0.05) occurred when the preferred temperature significantly increased with increasing acclimation temperature. The preferred temperature obtained graphically was 30.0 °C. Acclimation temperature significantly affected the thermal tolerance which increased with acclimation temperature. The thermal window calculated for A. ocellaris was 301.5 °C2. The thermal metabolic scope obtained in animals acclimated at the interval from 23 to 32 °C (P > 0.05) had a mean value of 4240.8 mg O2 h−1 kg−1 w.w., revealing that A. ocellaris is a eurythermal species with a range of optimal physiological performance that closely matches the environmental conditions where it can be farmed. Therefore, the highest value of the thermal aerobic scopes corresponded to the intervals of the preferred temperature obtained for A. ocellaris. These results may partially explain their worldwide distribution pattern, as well as their aquaculture potential in tropical regions.     

Chemical composition of the essential oil of Aloysia triphylla under seasonal influence and its anaesthetic activity in fish

Plants are sources of secondary metabolites, and some are rich in essential oils (EOs), which possess a bioactive pharmacological importance as sedatives and anaesthetics that have been experimentally demonstrated in fish. In search of products with lower residual effects and optimization of the production based on the local flora, the properties of the EO of Aloysia triphylla (EOAT) have been investigated. The samples of two years were analysed for the percentage variability of the chemical composition and the totality of the major components according to the season. Limonene, citral isomers (α and β), caryophyllene, caryophyllene oxide and spathulenol were the main constituents of the EOAT throughout these two years. In the second year, caryophyllene predominates over its oxide in all seasons; however, in the first year, it occurs only in autumn and winter. Seasonal pools of EOs were made for the biennium obtaining four samples, and silver catfish (Rhamdia quelen) juveniles were subjected to a concentration range of 20–800 μl/L EOAT in order to assess induction and recovery times of anaesthesia. The relationships between percentages of individual components in EOAT and time to induce deep anaesthesia indicate that its activity may be attributed to the association of several of its components.     

Turtles on the edge: movement of loggerhead turtles (Caretta caretta) along oceanic fronts, spanning longline fishing grounds in the central North Pacific, 1997–1998

Nine juvenile loggerhead sea turtles tracked during 1997 and 1998 in the central North Pacific by satellite telemetry all travelled westward, against prevailing currents, along two convergent fronts identified by satellite remotely sensed data on sea surface temperature (SST), chlorophyll and geostrophic currents. These fronts are characterized by gradients in sea surface height that produce an eastward geostrophic current, with gradients in surface chlorophyll and SST. Six of the turtles were associated with a front characterized by 17°C SST, surface chlorophyll of about 0.2 mg m^–3, and eastward geostrophic current of about 4 cm s^–1, while the other three turtles were associated with a front with 20°C SST, surface chlorophyll of about 0.1 mg m^–3, and eastward geostrophic flow of about 7 cm s^–1. These results appear to explain why incidental catch rates of loggerheads in the Hawaii longline fishery are highest when gear is set at 17°C and 20°C, SST. Further, from the seasonal distribution of longline effort relative to these fronts, it appears that the surface longline fishing ground lies largely between these two fronts during the first quarter and well to the south of the 17°C front, but including the 20°C front, in the second quarter. These findings suggest seasonal or area closures of the longline fishery that could be tested to reduce incidental catches of loggerheads. Finally, these results illustrate the insights which can be achieved by combining data on movement of pelagic animals with concurrent remotely sensed environmental data.