Is behaviour in a novel environment associated with bodily state in brown trout Salmo trutta fry?

Energetic status and body size are inconstant bodily states often considered to have feedback effects on behaviour. Feedbacks can be negative, like starvation‐threshold feedbacks (lower state values = increased risk taking due to higher energy need, and vice versa), or positive, like state‐dependent safety feedbacks (higher state values = lower vulnerability when expressing risky behaviours, and vice versa). Few studies have investigated feedback effects during the early‐life survival bottleneck of territorial species, when rapid growth is particularly important to maintain competitive ability. We investigated effects of body size and energetic status on the emergence latency into an unknown environment in highly territorial brown trout fry. We manipulated energetic status using high and low food rations in different combinations over two consecutive periods. In contrast to results from other small‐sized fishes, no general behavioural effects of energetic state were detected, but larger fish had on average shorter emergence latency. Starvation‐threshold feedbacks were not supported, but the size effect favours the presence of a state‐dependent safety feedback. When individuals were split into clusters characterised by long (>34 s) and short (<34 s) emergence latency, a state‐dependent safety feedback, based on energetic status, was found in the short‐latency cluster. Positive state‐dependent feedbacks may reflect the high level of competition among wild trout fry during the first summer, particularly among the more active individuals (i.e., from the short latency cluster). High state levels could be utilised to gain advantages over lesser competitors (e.g., to establish territories), particularly if the overall risk of starvation is higher than the risk of predation.     

Habitat amount and quality,not patch size,determine persistence of a woodland-dependent mammal in an agricultural landscape

Context

The classical theory of island biogeography explains loss of species in fragmented landscapes as an effect of remnant patch size and isolation. Recently this has been challenged by the habitat amount and habitat continuum hypotheses, according to which persistence in modified landscapes is related to total habitat amount rather than habitat configuration or the ability of species to use all habitats to varying degrees. Distinguishing between these theories is essential for effective conservation planning in modified landscapes.

Objective

Identify which factors of habitat type, amount and configuration predict the persistence of a keystone woodland specialist, the eastern bettong Bettongia gaimardi, in a fragmented landscape.

Method

In the Midlands region of Tasmania we carried out camera surveys at 62 sites in summer and winter. We included habitat and landscape features to model whether habitat amount or patch size and isolation influenced the presence of the eastern bettong, and to measure effects of habitat quality.

Results

Habitat amount within a 1 km buffer was a better predictor of occupancy than patch size and isolation. Occupancy was also affected by habitat quality, indicated by density of regenerating stems.

Conclusion

Our results support the habitat amount hypothesis as a better predictor of presence. For a species that is able to cross the matrix between remnant patches and utilise multiple patches, the island biogeography concept does not explain habitat use in fragmented landscapes. Our results emphasize the value of small remnant patches for conservation of the eastern bettong, provided those patches are in good condition.

     

Control of chlorophyll formation and sprouting of tubers by oil dipping in five potato cultivars of Pakistan

Five potato cultivars of autumn crop, dipped in corn oil, were observed for 90 days at room temperature under natural light. Chlorophyll formation took place in minute quantities in treated tubers of ‘Désirée’ and ‘Prima’, and a little more in ‘Primura’, ‘Montana’ and ‘Multa’, whereas all control tubers became completely green after 90 days. Sugars were significantly lower and starch higher in treated tubers than in controls. No sprout-development was observed in treated tubers of all cultivars, but 50–70% control tubers had sprouted during this period. Peeling-losses were minimum in treated tubers and were 67.5–85.4% in controls. The oil-dipped potato tubers of all cultivars could safely be stored for 60 days without quality deterioration under ordinary conditions of temperature and light.     

Contrasting edge and pasture matrix effects on ant diversity from fragmented landscapes across multiple spatial scales

Landscape Ecology - Harmful effects of habitat loss and fragmentation can be detected across multiple spatial scales, yet most studies that aim to characterize these effects take place at a single...     

The inheritance of patterned white flowers in zonal pelargoniums

White flowered cultivars have petals which are either pure white, or patterned white with coloured markings localized within clearly defined zones on the upper surface of the petals. Five patterns are identified. The bar pattern has pigment localized within a small zone on both sides near the base of each of the lower triplet of petals. The centre pattern has a V-shaped coloured zone in the basal half of all petals filling in the centre of the flower. The picotee pattern colours the edges of all petals. The ring pattern is a coloured zone running across the basal half of all petals. The vein pattern consists of two prominent coloured veins running from the base of the upper pair of petals. The expression of these patterns is controlled by the dominant alleles of four genes: the bar, picotee and vein patterns by the genes Baiba, Celce or PH pi, and Ve/ve respectively, and the centre and ring patterns by the interaction of the products of two genes Ce with Ve and Ba with Ve respectively. The homozygous recessive states of these genes are epistatic to the red- marking gene, Rm/rm, responsible for controlling the synthesis of anthocyanin pigments that fill the marked zones. Other colour marking genes are probably responsible for variations in colour, especially pink which was a frequent alternative to red. In the absence of the colour marking genes, the pattern zones may sometimes become lightly pigmented from other sources providing the pattern gene itself is present. The zones are considered to be areas of pigment accumulation rather than centres for pigment synthesis.     

Influence of rootstock on orchard productivity and fruit quality in peach cv. ‘Redhaven’

Summary

We have evaluated the influence of four different peach rootstocks (Prunus pumila,‘GF 655/2’ ,‘Missour’ and ‘GF 677’ as a standard) planted in medium-heavy to heavy soil on phenological events (flowering and harvest date), growth, yield, fruit quality and mortality of peach (P. persica L.) scions of cv. ‘Redhaven’. At the end of flowering, there were no significant differences between the different rootstocks in the years 1999, 2000, 2003 and 2004. In 2001, trees grafted on P. pumila reached the end of flowering 2 d before trees grafted on the other rootstocks. ‘Redhaven’ fruits ripened on the same day on trees grafted on the different rootstocks. The differences were only between years. The results showed that significantly less vigorous trees, according to their trunk cross-sectional area (TCSA) and canopy volume, with the lowest yield, were observed on P. pumila rootstock. The rootstock P. pumila had a significant negative influence on fruit dimensions and mortality was 50%. Trees grafted on ‘GF 655/2’ rootstock produced significantly lower yields than those grafted on ‘GF 677’ or ‘Missour’ rootstocks. Only the ‘GF 655/2’ rootstock had root suckers. Trees grafted on ‘GF 677’ rootstock were significantly more vigorous than on the other rootstocks, and produced the highest yield with good fruit quality. The final canopy volumes of peach trees grafted on the different rootstocks were very different. The most vigorous trees were those grafted on ‘GF 677’ rootstock, where the final tree volume was 12.8 m³. Trees grafted on P. pumila and ‘GF 655/2’ had significantly lower TCSA values than on the other rootstocks.     

Animal movement varies with resource availability,landscape configuration and body size: a conceptual model and empirical example

Landscape Ecology - Animals must move to find food, shelter and mates, and escape predation and competition. Changes in landscape configuration and resource availability can disrupt natural...     

Molecular characterisation of coconut (Cocos nucifera L.) varieties using ISSR and SSR markers

The present study was carried out to standardise a DNA isolation protocol for coconut and to characterize five coconut varieties using 18 inter-simple sequence repeat (ISSR) and 14 simple sequence repeat (SSR) markers. DNA was extracted from tender young leaf samples collected from the fronds of five different trees of each coconut variety. A protocol using 0.095 g ml^?1 glucose, 0.025 g ml^?1 polyvinylpyrrolidone, 0.0045 g ml^?1 sodium bisulphite, 0.0055 g ml^?1 sodium dodecyl sulphate, and 50 µl ml^?1 sarcosine produced good quality DNA. The average polymorphism percentages revealed using ISSR or SSR markers between the five varieties were 31.9% or 92.9%, respectively. Using ISSR markers, the overall similarity between all five varieties ranged from 0.657 to 0.775, whereas it was 0.037–0.304 using SSR markers. The levels of polymorphism detected using ISSR markers among the five samples each of ‘Banawali’, ‘Gangabondum Green Dwarf’, ‘Pratap’, ‘Konkan Bhatye Coconut Hybrid-I’, and ‘East Coast Tall’ were 23.2%, 24.2%, 25.6%, 27.1%, and 21.2%, respectively. The levels of polymorphism detected using SSR markers among the five samples of the same five varieties were 85.7%, 86.9%, 85.7%, 100%, and 92.9%, respectively. This study indicated that genetic variation existed both between and within samples of each of the five varieties of coconut. SSR markers were superior to ISSR markers. The extent of genetic variation obtained within a variety was not expected, so it is essential to maintain seed purity via artificial pollination.