A molecular analysis of the patterns of genetic diversity in local chickens from western Algeria in comparison with commercial lines and wild jungle fowls

The objectives of this study were to characterize the genetic variability of village chickens from three agro‐ecological regions of western Algeria: coastal (CT), inland plains (IP) and highlands (HL), to reveal any underlying population structure, and to evaluate potential genetic introgression from commercial lines into local populations. A set of 233 chickens was genotyped with a panel of 23 microsatellite markers. Geographical coordinates were individually recorded. Eight reference populations were included in the study to investigate potential gene flow: four highly selected commercial pure lines and four lines of French slow‐growing chickens. Two populations of wild red jungle fowls were also genotyped to compare the range of diversity between domestic and wild fowls. A genetic diversity analysis was conducted both within and between populations. Multivariate redundancy analyses were performed to assess the relative influence of geographical location among Algerian ecotypes. The results showed a high genetic variability within the Algerian population, with 184 alleles and a mean number of 8.09 alleles per locus. The values of heterozygosity (He and Ho) ranged from 0.55 to 0.62 in Algerian ecotypes and were smaller than values found in Jungle fowl populations and higher than values found in commercial populations. Although the structuring analysis of genotypes did not reveal clear subpopulations within Algerian ecotypes, the supervised approach using geographical data showed a significant (p < 0.01) differentiation between the three ecotypes which was mainly due to altitude. Thus, the genetic diversity of Algerian ecotypes may be under the influence of two factors with contradictory effects: the geographical location and climatic conditions may induce some differentiation, whereas the high level of exchanges and gene flow may suppress it. Evidence of gene flow between commercial and Algerian local populations was observed, which may be due to unrecorded crossing with commercial chickens. Chicken ecotypes from western Algeria are characterized by a high genetic diversity and must be safeguarded as an important reservoir of genetic diversity.     

Rigidoporus microporus and the white root rot disease of rubber

Rigidoporus microporus is an economically important plant pathogenic fungus causing particularly severe losses to the rubber industry worldwide. The pathogen is responsible for white root rot (WRR) disease, infecting the host roots via white fibrous mycelia, causing vascular disfunction, and visible symptoms including leaf discolouration and dieback in severely infected trees. The final stage of the disease is characterized by the appearance of basidiocarps at the tree collar. The development of WRR in rubber plantations is dependent on fungal diversity in the soil, pH, temperature, and cation levels. Several ‘-omics’ approaches have been undertaken to understand how R. microporus functions with the objective, ultimately, to control WRR. Unfortunately, no resistant rubber clone has been identified to date. The disease is managed through physical and chemical methods that are laborious and negatively impact the environment, respectively. Recent developments in research on R. microporus shed light on potential sustainable routes to WRR disease control using beneficial microorganisms and natural compounds. This review discusses the characteristics of R. microporus isolates from different geographical origins, the pathogenicity and virulence mechanisms of the necrotrophic fungal pathogen, factors that influence the development of WRR, recent findings from the multi-omics studies, and control methods that are available to combat this economically important pathogen.     

Inoculation with Phosphate Solubilizing Mesorhizobium Strains Improves the Performance of Chickpea (Cicer aritenium L.) Under Phosphorus Deficiency

The use of phosphate-solubilising bacteria as inoculants increases plant phosphorus (P) uptake and thus crop yield. Strains from the genus Mesorhizobium are among the most powerful phosphate solubilizing microorganisms. In order to study efficiency in P uptake and N₂ fixation in chickpea (Cicer aritenium), forty-two rhizobia strains natively from Tunisian soils were studied in symbiosis with the chickpea variety “Béja1” which is frequently cultivated in Tunisia. Plants were inoculated separately with these strains under controlled conditions in perlite under two sources of P i.e. soluble (KH₂PO₄) and insoluble P (Ca₂HPO₄). At flowering stage, growth, nodulation, P uptake and N₂ fixation were assessed in all symbiotic combinations. The results showed that the S27 strain efficiently mobilized P into plants, observed as a significant increase of plant P content when insoluble P (Ca₂HPO₄) was supplied to the soil. This was associated with a significant increase in plant biomass, nodule number and N content under insoluble P conditions. Additionally, inoculation with the Mesorhizobium strain S27 significantly increased the root acid phosphatase activity under insoluble P. This study also shows significant correlations found between plant P content and acid phosphatase activity under low P conditions which may highlight the contribution of acid phosphatases in increasing P use efficiency. A field experiment also showed that most of the chickpea analyzed parameters were improved when plants inoculated with two selected rhizobia strains (S26 and S27) and supplied with P2O5. Overall, these findings postulate that rhizobial inoculation should not only be based on the effectiveness of strains regarding N fixation, but also to other traits such as P solubilisation potential.     

Variation in quantity and quality of native forages and grazing behavior of cattle and goats in Tanzania

The study was conducted to assess the effects of seasonal variation in the quality and quantity of pasture and management of livestock exclosures (ngitili) on the grazing behavior of cattle and goats. The study was 2×2×2 factorial design with three independent variables: season (Dry or Rainy), ngitili management (Private or Communal) and animal species (Cattle or Goats). Focal and scan observation methods were used to record different behavioral activities. Vegetation attributes from the study areas were measured in two consecutive seasons. Most key forage species had significant higher crude protein (CP) content and in vitro organic matter digestibility (INVOMD) in rainy than in dry season (P<0.05), but Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) did not vary significantly with season (P>0.05). ADF and NDF were significantly higher in species from communal ngitili than those from private ngitili (P<0.05). Above-ground herbaceous biomass and bulk density (BD) were significantly higher in the rainy season and in the private ngitili than in the dry season and in the communal ngitili respectively. Cattle and goats spent considerably more time grazing and browsing respectively in the rainy season than in the dry season (P<0.05). Cattle foraging activities did not vary significantly (P>0.05) with ngitili management, but goats found to spend considerably more time browsing in the communal ngitili and more time grazing in the private ngitili (P<0.05). Despite the merits of stocking cattle and goats together in the heterogeneous pasture, seasonal variation in forage resources requires investigation of other strategies such as use of multipurpose trees and treatment of crop residues to improve livestock production.     

Molecular approach to determine taxonomic status of <Emphasis Type="Italic">Septoria</Emphasis> sp. causing leaf blotch of <Emphasis Type="Italic">Castanea sativa</Emphasis> in Hyrcanian forests

Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation methods were utilized with ITS regions sequencing to determine the taxonomic status of Septoria causing leaf blotch of C. sativa in Hyrcanian forests. The results indicated that the length of ITS region in the genus Septoria (extracted from GenBank) varied from 650 to 680 bp. There were almost three times more variable sites in ITS1 than in ITS2. The ITS2 secondary structure of Hyrcanian Septoria community had the highest similarity with Septoria castaneicola, except for some differences in helix II and III. Also, Hyrcanian samples had minimum genetic distances with S. castaneicola and maximum with Septoria quercicola. The maximum parsimony method divided the studied Septoria genus into three distinct clades, mostly located in clade I. Clade II consisted entirely of Septoria aciculosa, while clade III contained S. castaneicola as well as Hyrcanian samples.     

饲喂氨化棉籽壳对塔里木马鹿瘤胃内环境指标及血清尿素氮含量的影响

本试验旨在研究饲喂氨化棉籽壳对塔里木马鹿瘤胃内环境指标及血清尿素氮含量的影响,以期为塔里木马鹿对氨化饲料的合理利用提供理论依据。选用3只安装有永久性瘤胃瘘管的塔里木马鹿作为试验动物,采用配对试验设计(饲喂氨化棉籽壳前和饲喂氨化棉籽壳后),分2期进行,前期饲喂含未氨化棉籽壳(1 kg)的饲粮,后期饲喂用氨化棉籽壳全部替换掉未氨化棉籽壳的饲粮。每期试验分为预试期和正试期,预试期7 d,正试期15 d。结果显示:饲喂氨化棉籽壳后,塔里木马鹿瘤胃液p H、氨态氮浓度、微生物蛋白含量和血清尿素氮含量均显著或极显著高于饲喂氨化棉籽壳前(P0.05或P0.01),乙酸、丁酸和总挥发性脂肪酸浓度显著或极显著低于饲喂氨化棉籽壳前(P0.05或P0.01)。饲喂氨化棉籽壳前、后每只塔里木马鹿每天的饲料成本分别为5.55和5.04元,饲喂后比饲喂前低0.51元。由此可见,塔里木马鹿对氨化棉籽壳有很强的适应能力,氨化棉籽壳在塔里木马鹿饲粮中的应用可有效节约蛋白质饲料,提高粗饲料的利用效率,提高经济效益。     

Effect of the supplementation of live preys enriched in cod liver oil on the survival rate,growth and fatty acid profile of meagre (Argyrosomus regius) larvae

First‐feeding diets employed in the rearing of meagre (Argyrosomus regius) larvae are based on live preys that are commonly enriched to compensate for their deficiency of essential fatty acids. A feeding trial was conducted on meagre larvae (Argyrosomus regius) fed rotifer (Brachionus plicatilis) and Artemia salina enriched in lipids from an emulsion of cod liver oil (CLO) and a commercial product (CP). The effect of both enrichment products was evaluated on the survival rate, size and lipid composition of meagre larvae. The results showed that larvae fed CLO presented significant higher values of survival rate (35.0 ± 3.2%) and larval size (12.06 ± 1.17 mm) at the end of the experiment, compared to the CP diet (26.0 ± 2.5%, 11.41 ± 0.91 mm, respectively). Both zootechnical parameters were related to the content of polyunsaturated fatty acids in the larvae. Indeed, the larvae fed CLO presented a higher ratio DHA/EPA than those enriched in commercial product (0.82 ± 0.18 and 0.38 ± 0.12 at 26 days after hatching, respectively). Both larval groups presented similar body content of arachidonic acid (1.4 wt.% on average at 26 days after hatching), regardless the enrichment source. From all above, we can conclude that the enrichment of live preys with an emulsion of cod liver oil is an economically viable alternative to commercial products. Indeed, cod liver oil emulsions are able to fully meet the requirements for fatty acids of meagre larvae. Furthermore, cod liver oil is easily available from fish processing facilities.     

Impacts of rainstorms on soil erosion and organic matter for different cover crop systems in the western coast agricultural region of Syria

More and more cultivated coastal territories of Syria are being affected by increasing land degradation processes, specifically, by soil erosion due to non‐sustainable soil management. The use of cover crops can be considered an ideal solution to reduce the negative impacts of extreme rainfall events on soil erosion. However, there is no enough information about the main cultivated areas of Syria due to the current conflicts and the very few types of research conducted there. Therefore, the main aim of this research was to assess soil erosion (soil loss and sediment concentration) and hydrological response (run‐off and infiltration) considering the impact of different types of cropping systems on soil organic matter. To achieve this goal, using erosion plots, five grouped natural rainfall events and soil samples were collected, and infiltration measurements were performed between November 2012 and April 2013 (rainy season) on three different cropping systems (wheat, vetch, bean and control) with different sloping gradients (8% and 20%) in Tartous governorate (W Syria). Our results showed a cumulative rainfall amount from 68.8 to 201 mm during the study period. The highest sediment yield was generated in the control and wheat plots, registering 0.468 and 0.368 kg m^?2, respectively, with an inclination of 8%. For an inclination of 20%, the control and wheat plots registered 1.145 and 0.967 kg m^?2, respectively. In comparison with the control plots, there was a decrease in the total eroded organic matter, which ranged from 0.0579 (control) to 0.0289 (bean) kg m^?2 year^?1 in the plots with 20% inclination, and from 0.0233 (control) to 0.0069 (bean) kg m^?2 year^?1 with 8% inclination. To sum up, bean and vetch play an effective role to mitigate soil erosion, delay run‐off and reduce sediment yield. The output of this research provides first insights into the impact of different land uses on soil loss. Also, it could help rural inhabitants and farmers to correctly manage their soils against soil erosion processes.     

Physicochemical properties and bioactivity of nisin-containing cross-linked hydroxypropylmethylcellulose films

Cross-linked hydroxypropylmethylcellulose (HPMC) cast films with citric acid as polycarboxylic cross-linker were elaborated to study the effect of cross-linking level on various properties. Increased amounts of cross-linking agent were not connected to statistically different tensile strength and Young's modulus. Whatever the cross-linking level of the film was, the ultimate elongation parameter decreased by approximately 60% compared to the HMPC control film. Moisture sorption isotherms and water contact angle meter showed that the effect of cross-linking degree tends to reduce the hygroscopic and hydrophilic characteristics of films. In addition, to control bacteria growth on food surfaces, the antimicrobial activity of both 98% cross-linked HPMC-nisin and control HPMC-nisin films was tested on Micrococcus luteus. Despite the incorporation of a significant content of nisin, cross-linked HPMC-nisin films were completely inactive on the microbial strain compared to the HPMC-nisin control films. Cross-linking conditions likely either denatured the nisin or irreversibly bound nisin to the cross-linked HPMC. However, nisin adsorbed into films made from previously cross-linked HPMC maintained its activity.     

Investigating the effector suite profile of Australian Fusarium oxysporum isolates from agricultural and natural ecosystems

Pathogenic and putatively nonpathogenic isolates of Fusarium oxysporum are ubiquitously present in soils. Pathogenic isolates designated as formae speciales are very host specific. The genes that determine host-specific pathogenicity may be expected to be similar between strains within a forma specialis. Three different pathways were used for mining putative effectors from 85 assembled genome sequences representing isolates from the agricultural and natural ecosystems. A total of 436 putative effectors were identified, of which 115 were present in all the isolates. The presence–absence phylogeny showed some clustering of isolates based on the ecosystems, while some clustered with isolates from different ecosystems. Isolates from the agricultural and natural ecosystems shared 358 putative effectors. Agricultural isolates had 78 unique putative effectors, while isolates from the natural ecosystems had no unique effectors. Isolates from the natural ecosystems had effectors that have previously been confirmed with virulence functions in other filamentous fungi, suggesting that the natural ecosystems may be acting as a reservoir for pathogenic isolates awaiting compatible hosts. They also possessed putative effectors with domains involved in polysaccharide degradation. The putative effectors in the natural ecosystem isolates may be important for both parasitic and ecological fitness. Further analysis of the three characterized ff. sp.—lycopersici, niveum, and pisi—revealed high conservation in the pathogenicity mechanism in F. oxysporum. However, each strain had unique putative effectors, which may be responsible for host specificity.