Quantitative trait loci of frost tolerance and physiologically related trait in faba bean (Vicia faba L.)

In faba bean, field based winter-hardiness is a complex trait that is significantly correlated to frost tolerance. Frost tolerance could be used to indirectly select for faba bean winter-hardiness. The aim of this study was to identify putative QTL associated with frost tolerance and auxiliary traits and to quantify the efficiency of marker assisted selection. Thus, 101 recombinant inbred lines derived from the cross between two frost tolerant lines were tested for their hardened and unhardened frost tolerance and for their leaf fatty acid content in both treatments. Significant differences among the RIL were observed for all studied traits. For frost tolerance, five putative QTL were detected; three for unhardened frost tolerance that explained 40.7% (8.6% after cross-validation, CV) of its genotypic variance and two for hardened frost tolerance that explained 21.8% (1.0% after CV). For fatty acid content, three QTL were detected for oleic acid content in unhardened leaves that explained 62.9% (40.6% after CV) of its genotypic variance. This fatty acid was significantly correlated with unhardened frost tolerance. The unbiased genotypic variance explained enabled to draw realistic prospects of MAS for frost tolerance. In this study, combined MAS was more efficient than classical phenotypic selection and was expected to be higher on larger populations at early generations. Moreover, favourable alleles inherited from the exotic line BPL 4628 could be introgressed to European winter-hardy beans for further improvement.     

Developmental horizons in the pre‐natal development of the Greater cane rat (Thryonomys swinderianus)

The Greater cane rat (GCR, Thyronomys swinderianus) is a precocial rodent predominantly found within Africa. Economic and scientific interests have led to several research efforts towards the domestication and better understanding of the biology and development of this rodent. Despite these efforts, information on the pre‐natal development of this rodent is currently lacking. This study characterises distinct developmental milestones including skin pigmentation, emergence and distributions of hairs, calvarium consistency, teeth eruption, development of appendages, sensory organs and external genitalia in the pre‐natal GCR and assesses quantitative body parameters, that is body weight, body and crown–rump lengths across its entire gestation length (gestation days [GDs] 10‐140). Using these external features, we provide baseline reference ontogenetic scales for GCR embryos and fetuses, employable for stage, age and sex estimation of the pre‐natal GCR in future studies. We observed that the first evidence of an embryo was not seen before the end of the first trimester (GD50) and that the late second trimester (GD80‐GD100) marks the transition from embryogenesis to fetogenesis in the GCR. As both events occur at a much later developmental time point when compared to precocial non‐rodents including human, sheep and pig and slightly later when compared to other precocial rodents such as guinea pig, our data provide first indication that the pre‐natal GCR development might be associated with a reproductive delay. Together, this study expands our knowledge of the development and biology of the GCR, which will improve reproductive and breeding management, and native species conservation of this hystricomorph mammal.     

Pyogenic bacterial infections in humans with MyD88 deficiency

MyD88 is a key downstream adapter for most Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 deficiency in mice leads to susceptibility to a broad range of pathogens in experimental settings of infection. We describe a distinct situation in a natural setting of human infection. Nine children with autosomal recessive MyD88 deficiency suffered from life-threatening, often recurrent pyogenic bacterial infections, including invasive pneumococcal disease. However, these patients were otherwise healthy, with normal resistance to other microbes. Their clinical status improved with age, but not due to any cellular leakiness in MyD88 deficiency. The MyD88-dependent TLRs and IL-1Rs are therefore essential for protective immunity to a small number of pyogenic bacteria, but redundant for host defense to most natural infections.     

Fingerprinting sediment sources in the outlet reservoir of a hilly cultivated catchment in Tunisia

Purpose

Approximately 74 % of agricultural soils in Tunisia are affected by water erosion, leading to the siltation of numerous human-made reservoirs and therefore a loss of water storage capacity. The objective of this study was to propose a methodology for estimating the relative contributions of gully/channel bank erosion and surface topsoil erosion to the sediment accumulated in small reservoirs.

Materials and methods

We tested an approach based on the sediment fingerprinting technique for sediments collected from a reservoir (which has been in operation since 1994) at the outlet of a catchment (Kamech, 2.63 km²). Sampling concentrated on the soil surface (in both cropland and grassland), gullies and channel banks. A total of 17 sediment cores were collected along a longitudinal transect of the Kamech reservoir to investigate the origin of the sediment throughout the reservoir. Radionuclides (particularly caesium-137, ¹³⁷Cs) and nutrients (total phosphorus, total nitrogen and total organic carbon (TOC)) were analysed as potential tracers.

Results and discussion

The applications of a mixing model with ¹³⁷Cs alone or ¹³⁷Cs and TOC provided very similar results: The dominant source of sediment was surface erosion, which was responsible for 80 % of the total erosion within the Kamech catchment. Additionally, we showed that the analysis of a single composite core provided information on the sediment origin that was consistent with the analysis of all sediment layers in the core. We demonstrated the importance of the core sampling location within the reservoir for obtaining reliable information regarding sediment sources and the dominant erosion processes.

Conclusions

The dominance of surface erosion processes indicates that conservation farming practices are required to mitigate erosion in the agricultural Kamech catchment. Based on the results from 17 sediment cores, guidelines regarding the number and location of sampling cores to be collected for sediment fingerprinting are proposed. We showed that the collection of two cores limited the sediment source apportionment uncertainty due to the core sampling scheme to <10 %.     

Detection of Proteins in Starch Granule Channels

Proteins were detected in channels of commercial starches of normal maize, waxy maize, sorghum, and wheat through labeling with a protein‐specific dye and examination using confocal laser scanning microscopy (CLSM). The dye, specifically 3‐(4‐carboxybenzoyl)quinoline‐2‐carboxaldehyde (CBQCA), fluoresces only after it reacts with primary amines in proteins, and CLSM detects fluorescence‐labeled protein distribution in an optical section of a starch granule while it is still in an intact state. Starch granules in thin sections of maize kernels also had channel proteins, indicating that proteins are native to the channels and not artifacts of isolation. Incubation of maize starch with protease (thermolysin) removed channel proteins, showing that channels are open to the external environment. SDS‐PAGE analysis of total protein from gelatinized commercial waxy maize starch revealed two major proteins of about M_r 38,000 and 40,000, both of which disappeared after thermolysin digestion of raw starch. Commercial waxy maize starch granule surface and channel proteins were extracted by SDS‐PAGE sample buffer without gelatinization of the granules. The major M_r 40,000 band was identified by MALDI‐TOF‐MS and N‐terminal sequence analysis as brittle‐1 (bt1) protein.     

Phylogenetic and Molecular Characterization of the Equine Influenza Virus A (H3N8) Causing the 1997 and 2004 Outbreaks in Morocco

Reported here are the results of antigenic and genetic characterization of equine influenza strains causing local outbreaks reported in Morocco, respectively, in 1997 and 2004. The antigenic and genetic characterizations of the equine influenza virus H3N8 are reported here. The highest similarity between the HA1 nucleotide sequences of A/equine/Nador/1/1997 and those of A/equine/Rome/5/1991 and A/equine/Italy/1199/1992 demonstrate that A/equine/Nador/1/1997 belongs to the European lineage. On the other hand, A/equine/Essaouira/2/2004 and A/equine/Essaouira/3/2004 were classified in the predivergent lineage. The present work emphasizes the importance of a national influenza survey program, which requires a collaborative laboratory network to promote the collection and characterization (antigenic and genetic) of equine influenza viruses in real time.     

Ionic interactions and salinity affect monoterpene and phenolic diterpene composition in rosemary (Rosmarinus officinalis)

In this study, we evaluated how increased cation supply can alleviate the toxic effects of NaCl on plants and how it affects essential oils (EOs) and phenolic diterpene composition in leaves of rosemary (Rosmarinus officinalis L.) plants grown in pots. Two concentrations of the chloride salts KCl, CaCl₂, MgCl₂, and FeCl₃ were used together with 100 mM NaCl to study the effects of these nutrients on plant mineral nutrition and leaf monoterpene, phenolic diterpene, and EO composition. The addition of 100 mM NaCl, which decreased K⁺, Ca²⁺, and Mg²⁺ concentrations with increasing Na⁺ in leaves, significantly altered secondary metabolite accumulation. Addition of MgCl₂ and FeCl₃ altered leaf EO composition in 100 mM NaCl–treated rosemary plants while KCl and CaCl₂ did not. Furthermore, addition of CaCl₂ promoted the accumulation of the major phenolic diterpene, carnosic acid, in the leaves. The carnosol concentration was reduced by the addition of KCl to salt‐stressed plants. It is concluded that different salt applications in combination with NaCl treatment may have a pronounced effect on phenolic diterpene and EO composition in rosemary leaves thus indicating that ionic interactions may be carefully considered in the cultivation of these species to achieve the desired concentrations of these secondary metabolites.     

Comparative diagnostic potential of three serological tests for abortive Q fever in goat herds

Performances of an ELISA, an immunofluorescence assay (IFA) and a complement fixation test (CFT) were assessed for detecting antibodies against Coxiella burnetii after Q fever abortions in naturally infected goats. The goal of the study was to provide information useful for veterinary serodiagnosis in regard to categories of goats either experiencing Q fever abortion or not, blood sampling times and recommended cut-offs. The study was conducted on eight goat herds with evidence of C. burnetii abortions. In each herd, at least 5 goats that had aborted and 10 goats prior to parturition or at term were monitored 15, 30 and 60 days (D15, D30, D60) after the onset of Q fever abortion. The overall CFT results distribution did not differ between the two groups of goats and showed poor agreement with the ELISA results. In contrast, the ELISA and IFA results revealed comparable significant differences, but overall the ELISA test was slightly more sensitive than the IFA test. Seroprevalence, according to ELISA and IFA respectively, was higher in the aborting (88% and 82%) than in the non-aborting group (60% and 50%). High levels of serum antibodies were detected in goats post-abortion with an average of 114 %OD using ELISA and a log10(titer) of 2.4 using IFA. Strongly positive ELISA (%OD>80) and positive IFA results (log10(titers)>1.9) were significantly associated with abortion. Sampling on D15 gave the best association with ORs of 10 for ELISA and 6 for IFA. The practical interest of these results is discussed.     

Antibioisis and antixenosis resistance to Dactylopius opuntiae (Hemiptera: Dactylopiidae) in Moroccan cactus germplasm

Phytoparasitica - The wild cochineal, Dactylopius opuntiae (Cockerell), has become the main pest of the prickly pear [(Opuntia ficus-indica (L.) Miller] cactus crop in most of the Mediterranean...