Global analysis of Coffea canephora Pierre ex Froehner (Rubiaceae) from the Guineo-Congolese region reveals impacts from climatic refuges and migration effects

As the second species used for commercial coffee, evaluation of Coffea canephora Pierre ex Froehner population genetics is a challenging task for coffee breeding. This study examined the pattern of genetic variability and genetic relationships of cultivated and wild populations of C. canephora sampled across the Guineo-Congolese region of Africa and some improved populations maintained in field genebanks. A total of 293 individuals, sampled from 17 populations, were genotyped with 39 nuclear microsatellite markers. Genetic diversity and structure were investigated with both a model-based and a graphical approach; isolation by distance was also tested. Relationships between the diversity clusters are discussed with regard to differentiation due to several glacial refuges during the Last Glacial Maximum (LGM). High genetic diversity within C. canephora is confirmed with a mean number of alleles of 11.85 per marker, a mean gene diversity of 0.72 and a mean observed heterozygosity of 0.36. An overall structure of two main groups (Guinean and Congolese) subdivided in six subgroups (2 for the Guinean and 4 for the Congolese) was found, including one described for the first time in the Guinean group. A fine structure within the Guinean group was also newly detected. Genetic structure of C. canephora appears to be consistent with its geographic repartition at the continent scale. Structure of diversity was found in accordance with localizations of refuge zones during LGM and migration from this period. Results from this genetic structure study raise our capabilities to better manage and use the collections of genetics resources for breeding purposes. Those results will be used in future association studies to optimize the number of genotypes to be phenotyped.     

Clarification of Muscat musts using wheat proteins and the flotation technique

The bovine spongiform encephalopathy (BSE, mad cow) crisis has led some wine-makers to question gelatin as a fining agent and to reject the use of these animal proteins. The search for a substitute for gelatin was begun by comparing vegetable proteins (particularly gluten) with gelatin fining treatments. Clairette de Die (French-controlled appellation) is a sparkling sweet wine. The alcoholic fermentation begins in a tank, continues in a crown-cap bottle, and stops before the complete consumption of sugar. All particles present in the bottle have to be removed before corking, and it is important to have a must as clear as possible. This study concerned the clarifying of a Muscat must, treated with pectinases, using a very efficient flotation technique. The must is fined with bentonite/silica/protein (fish gelatin, wheat gluten, or lupin isolate) to induce flocculation and then pressurized (6 bar). After depressurization, microbubbles cling to flocculates and climb to the top of the flotation tank (this flotation foam is clarified using a rotary filter). At laboratory scale, gluten (20 g/hL) and gelatin (10 g/hL) (each combined with bentonite and silica gel) gave turbidities of 50 and 35 NTU, respectively (6.5 and 4.1% of that of the nontreated must). The Muscat must was also clarified by static settling. The turbidity decreased by 86% for the gluten/bentonite fining and by 60% for the gelatin/bentonite fining. Visually, gluten flocculation takes longer to occur and flocculates sedimentation is longer than with gelati, but the removal of insoluble particles is more complete and leads to lower turbidities. At an industrial scale, gluten (20 g/hL) and gelatin (10 g/hL) (each combined with bentonite and silica gel) gave turbidities of 60 and 48 NTU, respectively. Turbidities measured in the tanks 14 h after the flotation showed a better efficiency for the wheat gluten (24 NTU) compared to gelatin (28 NTU). This is explained by the static settling that completed the clarifying effect of the flotation. The last experiment showed comparable efficiencies for wheat gluten and lupin proteins. BSE caused a situation of crisis (in Europe particularly) leading the public and wine-makers to lose their confidence in the use of gelatin as fining agent and to reject animal proteins in general. It is proposed here that vegetable proteins could efficiently replace gelatin.     

Proteome analysis of the sarcoplasmic fraction of pig semimembranosus muscle: implications on meat color development

Two-dimensional electrophoresis was used to investigate sarcoplasmic protein expression in pig Semimembranosus muscles sampled 20 min after slaughter. Two groups (light and dark) of 12 animals were selected from 1000 pigs, based on meat L values measured 36 h postmortem. Twenty-two proteins or fragments (p < 0.05) were differentially expressed. Muscles leading to darker meat had a more oxidative metabolism, indicated by more abundant mitochondrial enzymes of the respiratory chain, hemoglobin, and chaperone or regulator proteins (HSP27, alphaB-crystallin, and glucose-regulated protein 58 kDa). Conversely, enzymes of glycolysis were overexpressed in the lighter group. Such samples were also characterized by higher levels of glutathione S-transferase omega, which can activate the RyR calcium channels, and higher levels of cyclophilin D. This protein pattern is likely to have severe implications on postmortem metabolism, namely, acceleration of ATP depletion and pH fall and subsequent enhanced protein denaturation, well-known to induce discoloration.     

A retrospective study of 30 cases of frozen lamellar corneal graft in dogs and cats

Frozen lamellar corneal grafts and nictitating membrane flaps were used in 18 dogs and 12 cats to repair deep corneal defects. In all dogs either melting corneal ulcers or descemetoceles were present. In the 12 cats, nine had either a melting corneal ulcer or descemetocele, two animals had acute bullous keratopathy, and one cat had corneal sequestrum. Initial vascularization with gradual clearing of the graft occurred during the first 45 days postoperatively. At 60 days postoperatively, all eyes were visual. Frequent postoperative complications included: focal dehiscence of the wound ( n  = 9); melting of part of the graft ( n  = 7); and pigmentation of the graft ( n  = 4). The frozen lamellar corneal graft was a very safe technique, and restored the tectonic and the optical function of the cornea. It provided the best results in corneas with nonperforating corneal defects. This technique provides poorer results when the cornea was perforated prior to surgery or during the surgical procedure.     

Effect of the Pietrain breed used as terminal boar on Post-weaning Multisystemic Wasting Syndrome (PMWS) in the offspring in four PMWS-affected farms

The aim of this study was to determine the potential risk factors for PMWS at the individual pig level and assess the effect of the Pietrain paternal genetic background of the animals in a cohort study. The survey was set up in four PMWS-affected farms with 2 repetitions (batches) per farm. A representative sample of 60 pigs per batch, stratified according to the paternal genetic background (Pietrain: yes vs. no), was randomly selected after farrowing. The representative cohort was divided into 8 batches and the pigs were individually monitored from birth to slaughter. Survival analysis was used to determine the factors related to the time to PMWS. The litter-cluster effect was taken into account using the marginal Cox model (robust estimation of the covariance matrix) and the gamma shared frailty model which were compared.No protective effect of the Pietrain breed on the time to PMWS and the proportion of affected pigs in the offspring was found in this study. Piglets showing low circovirus type 2 (PCV2) titres at 7 weeks-old with no subsequent seroconversion and piglets from PCV2 negative sows were most likely to be affected by PMWS (HR=7.0 and 2.8, respectively). Active infection of the pregnant dams with parvovirus was related to an increased risk of PMWS in the offspring (HR=2.3). Neck injuries due to poorly performed injections in the dams were associated with an increased risk of PMWS with the marginal model (HR=2.1). Oxytocin injection (dams) during farrowing was protective against PMWS in the offspring (HR=0.6).     

RAPD Characterization of Single Females of the Root-knot Nematodes, Meloidogyne Spp.

Random amplified polymorphic DNA fingerprinting was performed on single females of root-knot nematodes, Meloidogyne spp., using a new procedure for DNA isolation. One-fourth of the total DNA amount isolated from a single female proved to be sufficient as a template in a polymerase chain reaction. Electrophoretic patterns of the amplified fragments were reproducible between replicates from a single female or sister females from the same progeny, and identical to those obtained with genomic DNA purified from a large number of nematodes. Moreover, a comparative analysis over three successive generations showed stability of the amplification patterns, thus demonstrating the utility of this procedure for epidemiological and ecological studies on root-knot nematodes.     

Experimental and modeling studies showing the effect of lipid type and level on flavor release from milk-based liquid emulsions

The purpose of this work was to study two key parameters of the lipid phase that influence flavor release-lipid level and lipid type-and to relate the results to a mass balance partition coefficient-based mathematical model. Release of 10 volatile compounds from milk-based emulsions at 10, 25, and 50 degrees C was monitored by 1-min headspace sampling with a solid-phase microextraction fiber, followed by GC-MS analysis. As compared to the observations for milk fat, changing to a lipophilic lipid (medium-chain triglycerides, MCT) and adding a monoglyceride-based surfactant did not influence the volatiles release. However, increasing the solid fat content was found to increase the release. At 25 degrees C, and even more so at 10 degrees C, concurrent with an increase in their solid fat content, hydrogenated palm fat emulsions showed increased flavor release over that observed for emulsions made with coconut oil, coconut oil with surfactant, milk fat, and MCT. However, at 50 degrees C, when hydrogenated palm fat emulsions had zero solid fat content, there was no difference in flavor release from that observed for milk fat emulsions. Varying milk fat at nine levels between 0 and 4.5% showed a systematic dependence of the release on the lipid level, dependent on compound lipophilicity. Close correlations were found between the experimental and model predictions with lipid level and percent liquid lipid as variables.     

Morphological and physiological responses of beech (Fagus sylvatica) seedlings to grass-induced below ground competition

We examined morphological and physiological responses of beech (Fagus sylvatica L.) seedlings to grass-induced below ground competition in full-light conditions. Two-year-old beech seedlings were grown during two growing seasons in 160-l containers in bare soil or with a mixture of five grass species widely represented in semi-natural meadows of central France. At the end of the second growing season, beech seedlings in the presence of grass showed significant reductions in diameter and height growth, annual shoot elongation, and stem, root and leaf biomass, but an increase in root to shoot biomass ratio. Grasses greatly reduced soil water availability, which was positively correlated with daily seedling diameter increment. Beech seedlings seemed to respond to water deficit by anticipating stomatal closure. There was evidence of competition for nitrogen (N) by grasses, but its effect on seedling development could not be separated from that of competition for water. By labeling the plants with 15N, we showed that beech seedlings absorbed little N when grasses were present, whereas grasses took up more than 97% of the total N absorbed in the container. We conclude that, even if beech seedlings display morphological and physiological adaptation to below ground competition, their development in full-light conditions may be strongly restricted by competition from grass species.     

Isoflucypram,the first representative of a new succinate dehydrogenase inhibitor fungicide subclass: Its chemical discovery and unusual binding mode

Succinate dehydrogenase inhibitors (SDHIs) have played a crucial role in disease control to protect cereals as well as fruit and vegetables for more than a decade. Isoflucypram, the first representative of a newly installed subclass of SDHIs inside the Fungicide Resistance Action Committee (FRAC) family of complex II inhibitors, offers unparalleled long‐lasting efficacy against major foliar diseases in cereals. Herein we report the chemical optimization from early discovery towards isoflucypram and the first hypothesis of its altered binding mode in the ubiquinone binding site of succinate dehydrogenase. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Effects of physicochemical interactions and microbial activity on the persistence of Cry1Aa Bt (Bacillus thuringiensis) toxin in soil

Genetically modified crops, that produce Cry insecticidal crystal proteins (Cry) from Bacillus thuringiensis (Bt), release these toxins into soils through root exudates and upon decomposition of residues. The fate of these toxins in soil has not yet been clearly elucidated. Persistence can be influenced by biotic (degradation by microorganisms) and abiotic factors (physicochemical interactions with soil components, especially adsorption). The aim of this study was to follow the fate of Cry1Aa Bt toxin in contrasting soils subjected to different treatments to enhance or inhibit microbial activity, in order to establish the importance of biotic and abiotic processes for the fate of Bt toxin. The toxin was efficiently extracted from each soil using an alkaline buffer containing a protein, bovine serum albumin, and a nonionic surfactant, Tween 20. The marked decline of extractable toxin after incubation of weeks to months was soil-dependent. The decrease of extractable toxin with incubation time was not related to microbial degradation but mainly to physicochemical interactions with the surfaces that may decrease immunochemical detectability or enhance protein fixation. Hydrophobic interactions may play an important role in determining the interaction of the toxin with surfaces.