Lessons from a failed translocation program with a seabird species: Determinants of success and conservation value

Conservation diagnosis of ex situ techniques (e.g. releasing chicks by hacking) cannot be evaluated without quantitative assessment of the fate of individuals, mainly their survival and recruitment. Here we use a long-term monitoring at a large spatial scale of a hacking programme (i.e. chick translocations) for Audouin’s gulls in an uninhabited site so as to establish a new breeding patch and reinforce the metapopulation. The success of the programme relied on the assumption that birds tend to recruit to the site where they fledge (i.e. they were philopatric). Multi-state capture-recapture models applied to a large dataset (more than 43,500 resights at 30 colonies during 1999–2010) were used to evaluate the survival of released chicks and the probability of being philopatric. Adult survival was high, but juvenile survival was lower than that of wild gulls, suggesting that there was a cost associated with hacking only during their first year of life. As expected, most released birds returned to the hacking site, but very few (including immigrants from abroad) attempted to breed here. Dispersal was inversely correlated with distance from the hacking site and positively associated with the population size of the patch (i.e. conspecific attraction). Even though most hacking procedures met the ecological conditions to succeed, results clearly showed that the program failed to establish a new breeding site. The ability of prospecting and the attraction made by conspecifics at established sites may be a constraint for the success of hacking programs, particularly for social and nomadic species.     

Changes in caecal microbiota and mucosal morphology of weaned pigs

An experiment was designed to monitor the changes in caecal microbiota associated with early weaning. Twelve piglets (20+/-2 days) from six different litters were selected from a commercial source. For the two experimental groups, one animal from each litter was weaned onto a post-weaning diet (W) and the other remained with the sow (S). After 1 week, animals were sacrificed and caecal samples taken. Microbial counts for total bacteria, enterobacteria and lactobacilli populations were determined by quantitative PCR using SYBR Green dye. Microbial profiles were assessed by terminal restriction fragment length polymorphism (t-RFLP). Weaning promoted an increase in the enterobacteria:lactobacilli ratio (0.27 versus 1.67 log/log 16S rRNA gene copy number, P=0.05). Total bacteria and richness of the caecal microbial ecosystem (number of peaks) were similar in both experimental groups (49.3 for S and 53.4 for W, respectively, P=0.22), although the band patterns were clearly grouped in two different clusters by dendogram analysis. Weaning was also associated with a decrease in crypt density, an increase in mytotic index and a decrease in the number of goblet cells. A reduced immunological response was also observed and was manifested by an increase in intraepithelial lymphocytes and lymphocyte density in the lamina propria. Weaning appears to be critical in the establishment of the caecal microbiota in pigs with important changes, particularly in microbial groups and in caecal mucosal architecture.     

Antifungal activity of chili pepper extract with potential for the control of some major pathogens in grapevine

BACKGROUND

In recent years, biofungicides have drawn increasing interest in vineyards for a more sustainable integrated and copper-limited pest management. Among alternatives, botanicals could represent valuable tools, being rich sources of biologically active compounds. Conversely to the well-known antioxidant and biological properties in relation to health benefits, investigation on bioactivity of hot pungent Capsicum sp. products against fungal phytopathogens in vineyards is still scarce. Therefore, the present study aimed at exploring the biologically active compounds profile of a chili pepper (Capsicum chinense Jacq.) pod extract and its antimicrobial properties against some of the major fungal and Oomycetes pathogens of grapevine, including Botrytis cinerea Pers., Guignardia bidwellii (Ellis) Viala & Ravaz and Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni.

RESULTS

The ethyl acetate-extracted oleoresin from the most pungent varieties was rich in capsaicinoids and polyphenols (371.09 and 268.5 μg mg⁻¹ dry weight, respectively). Capsaicin and dihydrocapsaicin, hydroxycinnamic and hydroxybenzoic acids and quercetin derivatives were the most abundant, while carotenoids represented only a minor fraction. The oleoresin was efficient to inhibit all three pathogenic fungi and ED₅₀ values were determined, evidencing that G. bidwellii was the more sensitive (0.233 ± 0.034 mg mL⁻¹).

CONCLUSION

The results suggested a potentiality of chili pepper extract for the control of some important grapevine pathogens, their possible application being helpful for the recommended limitation in extensive use of copper in vineyard. The complex mixture of high amounts of capsaicinoids, associated to specific phenolic acids and other minor bioactive components might contribute to the observed antimicrobial action of chili pepper extract. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Volatile organic compounds in the roots and rhizosphere of Pinus spp.

Plant roots normally release a complex mixture of chemicals which have important effects in the rhizosphere. Among these different root-emitted compounds, volatile isoprenoids have received very little attention, yet they may play important and diverse roles in the rhizosphere, contributing to the regulation of microbial activity and nutrient availability. It is therefore important to estimate their abundance in the rhizosphere, but so far, there is no reliable sampling method that can be used to measure realistic rates of root emissions from plants growing in field conditions, or even in pots. Here, we measured root content of volatile isoprenoids (specifically monoterpenes) for Pinus pinea, and explored the feasibility of using a dynamic bag enclosure method to measure emissions from roots of intact pot-grown plants with different degrees of root cleaning. We also investigated a passive diffusion method for exploring monoterpenes in soil at incremental distances from mature Pinus sylvestris trees growing in field conditions. Total monoterpene content of P. pinea roots was 415±50 μg g⁻¹ fresh wt in an initial screening study, and between 688±103 and 1144±208 μg g⁻¹ dry wt in subsequent investigations. Emissions from shaken-clean roots of intact plants and roots of intact plants washed to remove remaining soil after shaken-clean experiments were 119±14 and 26±5 μg g⁻¹ dry wt h⁻¹, respectively. Emissions from intact roots in soil-balls were an order of magnitude lower than from shaken-clean roots, and probably reflected the amount of emitted compounds taken up by physical, chemical or biological processes in the soil matrix surrounding the roots. Although monoterpene content was not significantly different in droughted roots, emission rates from droughted roots were generally significantly lower than from well-watered roots. Finally, passive sampling of monoterpenes in the soil at different distances from mature P. sylvestris trees in field conditions showed significantly decreasing sampling rates with increasing distance from the trunk. We conclude that it is feasible to measure volatile isoprenoid emissions from roots but the method of root preparation affects magnitude of measured emissions and therefore must be decided according to the application. We also conclude that the rhizosphere of Pinus species is a strong and previously un-characterized source of volatile isoprenoid emissions and these are likely to impact significantly on rhizosphere function.     

Effect of Episodic and Regular Sewage Discharges on the Water Chemistry and Macroinvertebrate Fauna of a Mediterranean Stream

Physical, chemical and biological parameters were used to investigate the effects of regular and episodic sewage inputs,either domestic or industrial, on the water quality of a smallMediterranean stream (River Magro, eastern Spain). Although results from chemical analyses were useful for monitoring waterquality in areas where sewage discharge was regular, episodic andlocalised discharges from industries or farms were not detected by chemical analyses because sampling was performed seasonally. An adequately small number of macroinvertebrate taxa were foundto indicate water quality changes within R. Magro, and the presence/absence and relative abundance of these taxa can be usedas a simple, rapid, low cost method for detecting changes in water quality. Macroinvertebrates are highly sensitive to episodic sewage discharges, which are difficult to detect by classical physical and chemical monitoring.     

Occurrence and diversity of black-foot pathogens on asymptomatic nursery-produced grapevines in Turkiye

European Journal of Plant Pathology - Black-foot (BF) disease of grapevines in nurseries and young vineyards is caused by soil-borne Cylindrocarpon-like asexual morphs. They can be found both in...     

Mapping of QTL associated with seed chemical content in a RIL population of common bean (Phaseolus vulgaris L.)

The character of flat versus round fruit shape is controlled by a single gene (S/s) on chromosome 6 in peach [Prunus persica (L.) Batsch], with the flat fruit phenotype produced by the S/s heterozygous genotype. We used 16 simple sequence repeat (SSR) markers at the S/s region and physically mapped them in the peach sequence. Seven were mapped in the new F1 population from a cross between the two flat fruit cultivars 'UFO-3' and ‘Sweet Cap’ that segregated for the S/s gene. Fourteen of the SSRs were mapped in the Prunus reference map (T×E), of which seven had already been mapped and seven were added within this work. Our results confirmed the position of S/s on the distal part of chromosome 6. Thirteen of the initial 16 markers were also studied in a collection of flat (66) and round (39) cultivars, where some of the alleles were associated to the character and one of them, the 131 bp allele of marker UDP98-412, predicted in 98.4 % of the cases the flat shape. This allele was highly predictive of the flat fruit character in an additional collection of 100 cultivars, and is an useful tool for marker-assisted selection of flat peaches and nectarines, a trait that is becoming of increasing interest in breeding programs as consumption of these fruits is growing in the European market.     

Immunoreagent generation and competitive assay development for cyprodinil analysis

Cyprodinil is an anilinopyrimidine fungicide applied worldwide for the prevention and treatment of highly destructive plant diseases in a large variety of crops, including cereals, fruits, and vegetables. This paper describes the development of the first reported immunoassays for cyprodinil. Two original haptens have been synthesized and conjugated to different carrier proteins, and polyclonal antibodies have been produced. Moreover, competitive enzyme-linked immunosorbent assays have been developed and characterized for the analysis of this widely used pesticide. The influence of organic solvents and buffer conditions over the assay analytical parameters was studied. The IC(50) values of the optimized immunoassays were 1.6 and 2.8 ng/mL for the direct and indirect formats, respectively. Quantitative recoveries were found using spiked apple and grape juice samples after a simple direct dilution, and a limit of quantification of 20 ng/mL for both fruit matrices was achieved. These immunoreagents could be very valuable for the sensitive, straightforward, and rapid monitoring of cyprodinil residues in foodstuffs.