Chloroplast DNA analysis of eggplant (Solanum melongena) and related species for their taxonomic affinity

Summary Total chloroplast DNA (cpDNA) from Solanum incanum, a wild relative of eggplant, was used to probe total DNA of Solanum melongena (eggplant). The DNA fragments detected were the same as observed using purified chloroplast DNA. Chloroplast DNAs were also analysed for nine species of Solanum that are cross-compatible with eggplant: S. aethiopicum, S. anguivi, S. gilo, S. incanum, S. indicum, S. integrifolium, S. macrocarpon, S. olivare and S. panduriforme.Restriction fragments generated by eight enzymes were recorded as present or absent, and a matrix for all fragment positions, species and enzymes was used for cluster analysis. In the resulting dendrogram, the species tested formed three distinct groups: (1) S. aethiopicum, S. anguivi, S. gilo, S. indicum, S. integrifolium and S. olivare, (2) S. incanum, S. melongena and S. panduriforme, (3) S. macrocarpon. Six species of the first group belonging to section Oliganthes appears more closely related to the second group members belonging to section Melongena than does S. macrocarpon, which also belongs to section Melongena. Within the second group, S. panduriforme is slightly more like eggplant than is S. incanum.     

Modifying climate change habitat models using tree species-specific assessments of model uncertainty and life history-factors

Species distribution models (SDMs) to evaluate trees’ potential responses to climate change are essential for developing appropriate forest management strategies. However, there is a great need to better understand these models’ limitations and evaluate their uncertainties. We have previously developed statistical models of suitable habitat, based on both species’ range and abundance, to better understand potential changes of 134 tree species habitats in the eastern United States (http://www.nrs.fs.fed.us/atlas). Our focus here is to build on these results via a more robust assessment framework called modification factors (ModFacs) that is made up of five components. ModFac 1 addresses nine biological characteristics (e.g., shade tolerance and seedling establishment) that quantify the influence of species life-history traits. ModFac 2 considers 12 disturbance characteristics (e.g., insect pests, drought, and fire topkill) which address the capacity of a species to tolerate and respond to climate-induced changes in habitat. ModFac 3-5 distill the tree SDM results and facilitate communication of model uncertainty; we quantified the variability in projected change for General Circulation Models (GCM) and emissions scenarios (ModFac 3), the extent to which each species’ habitat intersects novel climate conditions (ModFac4), and accounted for long-distance extrapolations beyond a species’ current range (ModFac5). The life-history components of ModFacs 1 and 2 demonstrate the marked variability among species in terms of biological and disturbance characteristics, suggesting diverse abilities to adapt to climate change. ModFacs 3-5 show that the information from the SDMs can be enhanced by quantifying the variability associated with specific GCM/emission scenarios, the emergence of novel climates for particular tree species, and the distances of species habitat shifts with climate change. The ModFacs framework has high interpretive value when considered in conjunction with the outputs of species habitat models for this century. Importantly, the intention of this assessment was not to create a static scoring system, but to broadly assess species characteristics that likely will play an important role in adaptation to climate change. We believe these scores based on biological, disturbance, and model synthesis factors provide an important expansion of interpretive and practical value to habitat model projections.     

Behind the flaming zone: Predicting woody fuel consumption in eucalypt forest fires in southern Australia

Pre-fire woody fuel (diameter > 0.6 cm) structure and its consumption by fire were measured at experimental/prescribed fires and high intensity wildfires in eucalypt forests in southern Australia in order to better understand and model the dynamics of woody fuel consumption. Two approaches were used in model development: (1) a fire or plot level analysis, based on a dataset which includes the proportion of the pre-fire woody fuel load consumed at each fire; and (2) a stage level analysis, based on a dataset where woody fuel consumption was measured at a woody fuel particle level (i.e. pre-fire and post-fire diameter). For the plot level analysis a generalised linear model (GLM) approach identified the Forest Fire Danger Index (FFDI) as the best predictor of the proportion of woody fuel consumed, with an R² of 0.58 and mean absolute error of 10%. The stage level analysis recognised the various combustion stages through which a burning woody particle would pass, but failed to develop an accurate model that predicted the ignition, partial and full consumption of woody fuels based on fuel, fire behaviour and environmental variables. Analysis showed that consumption of woody fuel particles is highly variable and that variation in fire behaviour potentially has a greater impact on woody fuel consumption, than does variation in fuel characteristics (e.g. state of decay, fuel suspension and interactions with other fuel particles). The FFDI GLM provides forest and fire managers with a tool to manage woody fuel consumption objectives and may assist fire managers with forecasting post-frontal fire behaviour. The FFDI GLM may also assist forest and fire managers to better meet land management goals and to comply with air quality and emission targets.     

Post-fire survival and reproduction of rehabilitated and unburnt koalas

Fire can be a catastrophic event which causes high mortality and injury in wildlife. While rehabilitation of injured animals is common, no studies have measured the success of rehabilitated wildlife following fire. This study compared the long-term survival and reproduction of a group of injured, rehabilitated and released koalas (n=16) with that of uninjured koalas (n=23) following fires in fragmented forest in Port Stephens, Australia, in 1994. Individual koalas were monitored for up to three years following release. Survival rates were calculated using the Kaplan–Meier estimate, modified for the staggered-entry of new animals. There was no significant difference in the survival of rehabilitated and uninjured koalas after fire. Annual survival, derived by fitting an exponential decay function to the data, was estimated to be 58% for rehabilitated koalas and 67% for the uninjured koalas. Predation by dogs was the major cause of mortality for both groups. Reproduction did not differ significantly between the two groups over two breeding seasons following fire. It was concluded that rehabilitation of injured koalas was successful from the perspective of the individuals. Furthermore, such efforts have the potential to contribute to the recovery of populations depleted after fire and thus contribute to the long-term survival of koala populations.     

Board-invited review: St. Anthony's Fire in livestock: causes, mechanisms, and potential solutions

After a brief history of ergot alkaloids and ergotism, this review focuses on the metabolism and mechanisms of action of the ergot alkaloids. The authors provide models of how these alkaloids afflict grazing livestock under complex animal-plant/endophyte-environmental interactions. Alkaloid chemistry is presented to orient the reader to the structure-function relationships that are known to exist. Where appropriate, the medical literature is used to aid interpretation of livestock research and to provide insight into potential modes of action and alkaloid metabolism where these are not known for livestock. In closing the paper, we discuss management of ergot alkaloid intoxication in livestock and future research needs for this field of study.     

Antagonism of detomidine with tolazoline in isoflurane-anaesthetised ponies

The effects of tolazoline (4.0 mg/kg iv) antagonism of detomidine (0.02 mg/kg iv) were evaluated in isoflurane-anaesthetised, ventilated ponies. Each of 6 ponies received both tolazoline and saline treatment during separate anaesthetic episodes only (no surgery was performed). Detomidine administration produced an increase in blood pressure, decrease in heart rate and decrease in P_aO₂ Tolazoline treatment transiently increased heart rate while blood pressure returned to baseline after both treatments. Arterial oxygenation decreased further after tolazoline treatment while oxgenation recovered towards baseline with saline treatment. No other cardiopulmonary effects were detected. Recovery from anaesthesia tended to be more rapid when detomidine was antagonized. The potential benefit of antagonizing detomidine-induced bradycardia with tolazoline, during isoflurane anaesthesia should be weighed against the potential to produce a decrease in arterial oxygenation. The mechanism for this effect is not clear.     

A comparative study of young ‘Thompson Seedless’ grapevines under drip and furrow irrigation. I. Root and soil water distributions

Soilwater distribution, soilwater extraction, and root distributions were determined for young grapevines (Vitis vinifera L. cultivar ‘Thompson Seedless’) grown under drip and furrow irrigation near Fresno, CA, USA. Soilwater content and extraction was determined to a depth of 0.9 m by neutron scattering from an array of nine access tubes installed throughout one-quarter of the soil volume available to each vine. Root distribution was determined from root intersections with vertical planes established parallel and perpendicular to the vine row. Drip irrigation was applied daily according to estimated evapotranspiration, and furrow irrigation was managed according to 50% depletion of the plant available soil water. Drip and furrow irrigated vines showed similar water status and shoot growth patterns. There was a confined soil wetted zone beneath the emitter discharge that largely coincided with a confined and shallow root system of drip irrigated vines. In contrast, furrow irrigated vines had a deeper and more widespread root system. Differences between water applied and soilwater content 3 days after irrigation suggested large water losses by evaporation during that period for furrow irrigated vines. Consumptive use of furrow irrigated vines was 12.5% greater than drip irrigated vines, but similar irrigation efficiencies were obtained for both irrigation systems when soilwater status was carefully monitored. Water applications for both irrigation systems were less than 50% of the longterm mean for irrigation deliveries to farms in the area. Thus, the results indicate that a significant potential for water savings exists in the San Joaquin Valley by means of irrigation management. It is concluded that relatively high and similar irrigation efficiency can be obtained with both drip and furrow irrigation of young grapevines in arid and semiarid regions when careful management is used.