Molecular and morphological characterization of Golestan (Iran) olive ecotypes provides evidence for the presence of promising genotypes

Unidentified olive plants naturally grow in the Golestan province of Iran, on different soils and under climates spanning from sub-temperate to desert conditions, represented by single trees or groups of few trees. We collected samples from representative sites and analyzed them by simple sequence repeat markers in order to determine their identity and their relationships to prominent Iranian and Mediterranean reference cultivars. Population structure analysis separated these ecotypes from Mediterranean and, surprisingly, from all Iranian cultivars, the parentage test excluded their direct contribution as candidate parents or offspring of cultivars, and they also showed a high level of admixture. Their differentiation from cultivated olives may be attributed to different factors: they could represent wild plants or could derive from natural dissemination of ancestral cultivated trees. Their survival up to now may be due to the fact that most of them are grown on sacred sites such as necropolis. Anyhow, the adaptation to strong environmental stresses, and their fruit size and oil content make the olive Golestan ecotypes a valuable source of genetic variation previously uncharacterized and currently threatened with extinction.     

Drought tolerance in four-day-old seedlings of a drought-sensitive cultivar of wheat

Four-day-old seedlings of spring wheat (Triticum aestivum L. cv. Marvdasht) can tolerate severe dehydration and recover after re-watering. In order to clarify tolerance mechanism, in a completely randomized design, the seedlings were exposed to drought by complete water cessation for 10 and 20 days, followed by re-watering for 3 and 7 days. Upon dehydration, the activity of α-amylase increased whereas growth parameters; photosynthetic pigments; and the activities of lipoxygenase, indole acetic acid (IAA) oxidase, and ascorbate peroxidase (APX) decreased. The activity of APX and the expression of its gene, however, increased after re-watering. Prolonged dehydration was also accompanied by increase in sucrose, soluble proteins, fructans, and certain amino acids, e.g. proline, glutamine, and valine. The results indicated that during dehydration, 4-day-old wheat seedlings shifted their energy expenditure from basal metabolism to withstand water deficiency via lowering the activity of membrane-damaging enzymes and enhancing the production of osmoprotectants.     

Synthesis of highly intercalated urea-clay nanocomposite via domestic montmorillonite as eco-friendly slow-release fertilizer

The present study describes the preparation and characterization of montmorillonite-urea nanocomposites (Mt-Ur) using aqueous suspension technique at various stirring times and different ratio of montmorillonite to urea (Mt/Ur) via an impure and domestic montmorillonite (Mt), without the application of any chemical reagents and high-energy-demand process (environmentally friendly). The intercalation of urea into Mt interlayer was clearly demonstrated by a significant expansion of d₀₀₁ spacing (interlayer space of Mt) from 1.23 to 1.71 nm which has not yet been reported by aqueous suspension technique. Analyses performed by Fourier transform-infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) also confirmed the effectiveness of this simple process to intercalate the urea into clay lamella. The release pattern demonstrated that the nanocomposite had a slow-release behaviour for urea dissolution. The results also suggested that the Mt type applied in the current study, in a 1:20 Mt/Ur ratio and stirred for 1 h, possessed desirable ecological and economic efficiency in the production of slow-release urea fertilizer due to the application of the impure and domestic clay which is of very low-cost and eco-friendly. Nevertheless, urea was fully intercalated into the interlayer of clay by a simple technique and with a good slow-release behaviour.     

A global meta-analysis shows soil nitrogen pool increases after revegetation of riparian zones

Purpose

Sustainable management of riparian zone soils is required to ensure the health of natural ecosystems and maintenance of soil nitrogen (N) pools and soil N cycling. However, the effect of revegetation type and age on soil N pools remains poorly understood.

Materials and methods

This study compiled data from published articles to understand the effects of revegetation types and age on soil total N (TN) and soil inorganic N (NH₄⁺-N, and NO₃^?-N) using a meta-analysis. We extracted 645 observations from 52 published scientific articles.

Results and discussion

The revegetation of riparian zones led to a significant increase of soil TN (mean effect size: 11.5%; 95% CI: 3.1% and 20.6%). Woodland increased soil TN significantly by 14.0%, which was associated with the presence of N fixing species and high litter inputs. Soil NH₄⁺-N concentration significantly increased (mean effect size: 20.1%; 95% CI: 15.1% and 25.4%), whereas a significant decrease in soil NO₃^?-N (mean effect size: ? 21.5%; 95% CI: ? 15.0% and ? 27.5%) was observed. Of the revegetation types considered in this paper, NO₃^?-N concentration in soil followed the order: grassland < shrubland < woodland, suggesting that woodland might be more efficient in soil NO₃^?-N retention than grassland. The high plant N uptake and accelerated NO₃^?-N leaching in grassland could be related to the decreased soil NO₃^?-N in grassland compared with other revegetation types. Revegetation significantly decreased soil moisture by (mean effect size: ? 7.9%; 95% CI: ? 3.3% and ? 12.2%) compared with the control, which might be associated with the selection of exotic species as dominant vegetation in the riparian zone. Soil TN increased in revegetation ages between 10 and 40 years following revegetation and was related to increased soil organic carbon inputs within those ages following the establishment.

Conclusions

This study provides insight into influence of different vegetation types and age on soil N pools and soil moisture. This study also highlights the importance of revegetation in riparian zones to increase soil TN.

     

Appraisal of 15N enrichment and 15N natural abundance methods for estimating N2 fixation by understorey Acacia leiocalyx and A. disparimma in a native forest of subtropical Australia

Purpose  

It is anticipated that global climate change will increase the frequency of wildfires in native forests of eastern Australia. Understorey legumes such as Acacia species play an important role in maintaining ecosystem nitrogen (N) balance through biological N fixation (BNF). This is particularly important in Australian native forests with soils of low nutrient status and frequent disturbance of the nutrient cycles by fires. This study aimed to examine ¹⁵N enrichment and ¹⁵N natural abundance techniques in terms of their utilisation for evaluation of N₂ fixation of understorey acacias and determine the relationship between species ecophysiological traits and N₂ fixation.     

Gastritis and gastric perforation due to Habronema spp. in the horse

A three-year-old horse was admitted to the Tehran Veterinary faculty teaching hospital with colic symptoms. The horse died with severe pain after two hours. Necropsy findings revealed a heavy worm infestation in the stomach. Parasitological examinations identified massive in vasion of Habronema muscae on the stomach mucosal surface and Draschia megastoma in the deep layer of mucosa and muscles.Histopathological sections showed two separate lesions including diffuse infiltration of mononuclear inflammatory cells with a number of eosinophils in the mucosa and submucosa that suggested eosinophilic gastritis. Another finding was a large granulation mass in the deep layer of the submucosa that contained granulomatous necrotic tissue and cross sections of D. megastoma.     

Effect of Delayed Icing on the Microbiological,Chemical, and Sensory Properties of Caspian Sea Golden Grey Mullet (Liza aurata)

Research has shown that fresh fish is an extremely perishable food as compared to other food commodities. In this study, quality deterioration during storage of golden grey mullet (GGM) iced for 0, 6, and 12 h after landing was monitored. Microbiological indices (total viable count, TVC; psychrophilic counts, PTC; lactic acid bacteria, LAB; and Enterobacteriaceae counts, EBC), chemical parameters (pH; total volatile basic nitrogen, TVB-N; peroxide value, PV; thiobarbituric acid, TBA; and free fatty acids, FFA) values increased over the preicing duration. Delayed icing did not lead to significant increases (p > 0.05) in TVC, PTC, LAB, and EBC throughout the period of storage. All chemical indices increased during storage (p < 0.05). This study showed that sensorial analysis of GGM correlated well with microbiological analysis. Results of this study based on the microbiological and raw fish sensorial data indicated that the shelf life of GGM stored in ice immediately after catch was approximately 10–11 days, while the 6- and 12-h delays in icing shortened the shelf life to approximately 6–7 and 2–3 days, respectively.     

Short-term effects of organo-mineral enriched biochar fertiliser on ginger yield and nutrient cycling

Purpose

Biochar has agronomic potential but currently is too expensive for widespread adoption. New methodologies are emerging to reduce the cost such as enriching biochar with nutrients that match crops and soil requirements. However, the effects of biochar-based fertilisers on plant yield and soil nutrient availability have not been widely examined. This study investigated the effects of a novel organo-mineral biochar fertiliser in comparison to organic and commercial biochar fertiliser on ginger (Zingiber officinale Canton).

Materials and methods

There were four treatments: (1) commercial organic fertiliser (5 t ha^?1), as the control; (2) commercial biochar-based fertiliser (5 t ha^?1); (3) organo-mineral biochar fertiliser at low rate (3 t ha^?1); and (4) organo-mineral biochar fertiliser at high rate (7.5 t ha^?1). A replicated pot trial was established with black dermosol soil and ten replicate pots for each treatment. Ginger was planted and grown for 30 weeks. Plant growth, biomass, foliar nutrients and water extractable soil nutrients including phosphorus (P), potassium (K) and calcium (Ca) were examined.

Results and discussion

High rate organo-mineral biochar fertiliser increased soil P and K availability at week 30 (harvest) after planting, compared to all other treatments and low rate organo-mineral biochar fertiliser performed similarly to the organic control for P and K. High rate organo-mineral biochar fertiliser increased total foliar nutrient content at week 30 in P, K and Ca compared to commercial biochar fertiliser. High rate organo-mineral biochar fertiliser improved the commercial value of ginger (+?36%) due to a shift in the proportion of higher grade rhizomes. Low rate organo-mineral biochar fertiliser plants displayed similar yield, total dry and aboveground biomass to commercial organic fertiliser. Commercial biochar fertiliser had significantly lower biomass measures compared with other treatments as the rate applied had lower nutrient concentrations.

Conclusions

Our results show organo-mineral biochar fertilisers could be substituted for commercial organic fertilisers at low rates to maintain similar yield or applied at high rates to increase commercial value where economically feasible.

     

A novel method for manufacturing nanofibers

This study presents a method for the fabrication of ultrafine polymeric nanobers utilizing centrifugal and electrostatic forces simultaneously. To reduce the diameter and variability of nanofibers produced from polyacrylonitrile (PAN) and poly-L-lactic acid (PLLA), a unique electro-centrifuge spinning device was designed using rotating nozzle and collector, whereas the fabrication process (spinning head) was skillfully sealed from ambient airflow. The polymer solution was continuously delivered by a rotating nozzle and the nanofibers were collected by a rotating cylindrical collector at the same rotational speed as the nozzle. Field emission scanning electron microscope (FESEM) results demonstrated that this method has a significant effect on the quality and fineness of nanofibers. The diameters of nanobers were controlled by adjusting the rotation speed of spinning head. The effect of the rotation speed on the morphology of the nanofibers fabricated by this device was also evaluated. In order to provide a useful context for the current nanofiber production method, nanofibers obtained in this method were compared with those produced by other methods. The results show that air-sealedcentrifuge-electrospinning system (ASCES) is a facile method for the fabrication nanobers with smaller diameters and high uniform structures.     

Molecular Genetic Analysis of the Variable Number of Tandem-Repeat Alleles at the Phenylalanine Hydroxylase Gene in Iranian Azeri Turkish Population

Background:

The variable numbers of tandem-repeat (VNTR) alleles at the phenylalanine hydroxylase (PAH) gene have been used in carrier detection and prenatal diagnosis in phenylketonuria families. This study was carried out to analyze VNTR alleles at the PAH gene in Iranian Azeri Turkish population.

Methods:

In this study, 200 alleles from general population were studied by PCR.

Results:

The frequencies of VNTR alleles were 45%, 46%, 2%, 3%, 1%, and 3% in studied group regarding 3, 8, 9, 11, 12, and 13 repeat copies, respectively. Statistically significant differences were not found between expected and observed frequencies of VNTR genotypes (P > 0.05).

Conclusions:

VNTR alleles with three and eight repeats were frequent, and the VNTR alleles with 13 repeats showed 3% frequency in the tested group. This study is the first report on tested population genetic structure using VNTR alleles at the PAH gene. Key Words: Phenylalanine hydroxylase, Population genetics, Variable numbers of tandem-repeat