Trace metal distribution in pelagic fish species from the north-west African coast (Morocco)

International Aquatic Research - In the current study, ten elements contents (Fe, Zn, Mn, Cu, Cr, Co, Ni, Cd, Pb and Hg) have been measured in muscle and liver of four pelagic fish species...     

Adsorption of Lead,Cadmium, and Nickel on Benchmark Soils of Pakistan

Eurasian Soil Science - Adsorption and desorption reactions at the solid phase–solution interface, play a significant role in controlling metal concentrations in soil solution and metal...     

In vitro clonal propagation of mature Tectona grandis through axillary bud proliferation

An in vitro clonal propagation procedure for mature Tectona grandis (teak) trees is described. Multiple shoots were induced from nodal segments through axillary bud proliferation. A shoot multiplication rate of 6.33 was achieved on Murashige and Skoog's (MS) medium supplemented with 10 μM 6-benzyladenine BA and 1 μM 1-naphthalene acetic acid (NAA) during every subculture cycle of 4 weeks. In vitro raised shoots could be successfully rooted (66.66%) on liquid MS medium supplemented with 15 μM NAA, with 1.60 roots per shoot, every 6 weeks of culture. In vitro hardening was carried out in sand soaked with half-strength MS medium (organic free). The plantlets were acclimatized first in a mist chamber and then in polybags in a mixture of soil, sand, and farmyard manure (1 : 1 : 1 v/v) in a shade house.     

Effect of jasmonic acid on the induction of polyphenoloxidase and peroxidase activities in relation to date palm resistance against Fusarium oxysporum f. sp. albedinis

Bayoud, caused by Fusarium oxysporum f. sp. albedinis (Foa), is the most damaging disease of date palm in Morocco. In the present study we have investigated the effect of jasmonic acid (JA) on two defence-related enzymes, namely peroxidases (POX) and polyphenoloxidases (PPO) in date palm seedlings root. Our data show that exogenous application of JA at a concentration of 50 μM increased the activity of both enzymes. The increase of POX activity in the presence of JA was much more important than that observed following infection with the pathogen. As compared to untreated plants, PPO activity was 2.2 and 1.3 times higher in BSTN and JHL cultivars respectively. In addition, PAGE analysis revealed increased band intensity of the major constitutive isoforms of POX and PPO in both JA-treated and Foa-treated seedlings. Close examination of symptomatic and asymptomatic plants showed that root tissues of symptomatic plants were massively colonized by Foa. Also, disease development in these plants appeared to involve a marked degradation of the host cell walls early during the process of pathogen invasion. In contrast, the presence of Foa in asymptomatic plants induced limited necrotic lesions (hypersensitive-reaction like lesions) that were probably involved in reducing the progression of the pathogen. Together, our findings indicate that JA is capable of enhancing date palm root resistance to infection by Foa via the activation of defence-related enzymes such as PPO and POX.     

Field and controlled conditions screenings of some faba bean (Vicia faba L.) genotypes for resistance to the parasitic plant Orobanche crenata Forsk. and investigation of involved resistance mechanisms

Journal of Plant Diseases and Protection - The parasitic weed Orobanche crenata is a serious constraint to legumes crops in Mediterranean area. In Morocco, heavy O. crenata infestation level was...     

Genetic and pathogenic diversity within Ascochyta rabiei(Pass.) Lab. populations in Pakistan causing blight of chickpea (Cicer arietinum L.)

Pathogenic and genetic diversity in Ascochyta rabiei populations in Pakistan were evaluated. Biological pathotyping of 130 A. rabiei isolates (obtained from hierarchically collected samples) was conducted on a set of three chickpea differentials, i.e. ILC 1929 (susceptible), ILC 482 (tolerant) and ILC 3279 (resistant), under controlled conditions. Disease severity data were recorded 12 days after inoculation. Statistical analysis grouped the isolates into three pathotype classes. Four isolates belonged to pathotype I (least aggressive), 79 isolates to pathotype II (medium aggressive) and 47 isolates to pathotype-III (highly aggressive).Genetic analysis was performed using RAPDs and oligonucleotide fingerprinting, where Hinf I-digested DNA was hybridized to the³²P-endlabeled oligonucleotide probes (CAA)₅, (GAA)₅, (GA)₈, (CA)₈and (GATA)₄. Dendrograms produced by cluster analysis discriminated 46 genotypes in the A. rabiei population of Pakistan. Genetic distances and relatedness between isolates were calculated. At a genetic distance of 0.3, genotypes were divided into six distinct genotype groups A, B, C, D, E and F containing 16, 11, 2, 5, 5 and 7 isolates, respectively. Most of the genotypes were area specific or predominated in certain areas but did not belong to a distinct pathotype, while most of the aggressive isolates (pathotype III) occurred in Northern Punjab and in the North Western Frontier Province.     

Natural occurrence, identification and transmission of the phytoplasma associated with flax phyllody and stem fasciation in Pakistan

Flax plants (Linum usitatissimum) of the white (album) flower variety exhibiting typical phytoplasma-like symptoms were found for the first time in Pakistan during 2011. The symptoms included floral virescence, phyllody, little leaf, stunting and stem fasciation. Light microscopy of hand-cut stem sections treated with Dienes’ stain showed blue areas in the phloem region of symptomatic plants. To confirm phytoplasma infection, total DNA was extracted separately from five plants showing virescence/phyllody and from five others showing fasciation, and was amplified by nested PCR using universal 16S rDNA phytoplasma primers P1/P7 followed by R16F2n/R16R2. All samples from plants with virescence/phyllody and fasciation yielded a 1,250 bp PCR product, and identical RFLP profiles using the enzymes AluI and HpaII. Direct sequencing of the 16S rDNA of one representative PCR amplicon (GenBank Accession No. JX567504 for phyllody and Accession No. JX567505 for fasciation) showed highest sequence identity (99%) with 16SrII ‘Candidatus Phytoplasma aurantifolia’ phytoplasmas, and phylogenetic analysis placed the phytoplasma in subgroup 16SrII-D. Disease was successfully transmitted by grafting and by the leafhopper Orosius albicinctus. To our knowledge, flax is a new natural host for 16SrII-D phytoplasmas in Pakistan.     

Variations of chemical composition of two Algerian essential oils collected for different seasons and assessment of their insecticidal toxicity against three moth pests

Journal of Plant Diseases and Protection - The aims of this work were to point out the seasonal variation in chemical composition and evaluate the insecticidal activities of Mentha spicata and...     

Corn flour-mimosa tannin-based adhesives without formaldehyde for interior particleboard production

A formaldehyde-free adhesive consisting of a corn flour/NaOH adhesive mixture and a mimosa tannin/hexamine intermediate component was developed and evaluated for application to wood panels such as particleboards. The main ingredients of this adhesive include corn flour, NaOH, mimosa tannin and hexamine. This study investigated the physical properties (rheological and thermal analysis) of corn flour/NaOH and mimosa tannin/hexamine adhesives as well as mechanical properties of particleboards produced with these adhesives. Thermomechanical (TMA) experiments indicate the best performance of the adhesives to be around the relative mass proportions of 50:50 between corn flour/NaOH and mimosa tannin/hexamine. Former NMR measurements on corn starch and mimosa tannin proved that the two components behave as a polymer blend rather than co-reacting. The laboratory results show that particleboards bonded with the adhesive at this optimal ratio show good mechanical properties. Moreover, the formaldehyde emission levels obtained from boards bonded with the optimal adhesive were considerably lower to those obtained from boards made with control urea formaldehyde.     

Aerobic biodegradation of precoagulated cheese whey wastewater

Prior to the application of an aerobic biological process, cheese whey wastewater has been pretreated by means of a precipitation stage by adding either NaOH or CaOH2. Both precipitating agents reduce roughly 50% of the raw wastewater chemical oxygen demand (COD). The sludge generated in the prestage shows acceptable settling properties, although solids from the CaOH2-treated effluent are better separated from the liquid bulk than those formed in NaOH-processed wastewater. In both situations, the presedimentation stage renders a supernatant more prone to biodegradation than the untreated effluent. The previous statement is corroborated by the determination of some biological kinetic parameters. Under the operating conditions used in this work, sludge generation after the biological process is reduced to a minimum. The sludge generated shows good settling properties, especially for those experiments in which CaOH2 has previously been added.