Differential Response to Salt Stress Within and Among Iranian Melilotus Species

This paper explores the salt-tolerance response of Melilotus species, a forage legume, based on tolerance/susceptibility indices, leaf water relations, leaf/root ion concentrations and multivariate (factor and function discriminate) analyses. In a greenhouse experiment, salinity-susceptibility of 12 accessions of Melilotus (M. albus, M. indicus, M. officinalis) in addition, two controls (alfalfa and Persian clover) were evaluated at 0 mM, 100 mM, 200 mM, and 300 mM of sodium chloride (NaCl). The experiment was conducted in a split plot design with two replications. Stress tolerance score (STS) was calculated based on tolerance/susceptibility indices. Salt-tolerant accessions were identified. An extracted bi-plot based on factor analysis confirmed the results of tolerance/susceptibility indices. There were significant correlations between STS and multivariate statistics. Root potassium cation (K⁺) concentration was higher in Melilotus species than the control species in all the salinity treatments. STS, root K⁺ concentration, leaf turgidity, and leaf succulence characteristics can be used for screening salinity-tolerance in Melilotus accessions. In all treatments, M. officinalis, M. indicus, and M. albus were salinity-tolerant species in descending order.

Abbreviations: Total biomass yield under control (Yp) and stress (Ys) mediums, geometric mean productivity (GMP), leaf area (LA), leaf tissue density (LTD), linear regression coefficient (b), mean productivity (MP), relative water content (RWC%), Succulence (S), specific leaf area (SLA), stress susceptibility index (SSI), stress tolerance index (STI), tolerance (TOL), water content at saturation (WCS), water saturation deficit (WSD), sodium chloride (NaCl), potassium cation (K⁺), sodium cation (Na⁺), analysis of variance (ANOVA), least significant difference (LSD), alfalfa control accession (CHA), Persian clover control accession (CHC), coefficient of variation (CV), statistics of factor (F) and discriminate function (D)     

Investigation on the Biodegradability and Antibacterial Properties of Nanohybrid Suture Based on Silver Incorporated PGA-PLGA Nanofibers

Polyglycolic acid-poly lactic glycolic acid (PGA-PLGA) electrospun nanofibers containing silver nanoparticles have been produced and twisted into the nanofibrous yarn. The morphology of nanofibers and produced yarns, as well as the mechanical properties of the yarns, were investigated. Furthermore, in vitro antibacterial properties and in vitro degradation behavior of yarns containing various silver nanoparticles were studied. SEM images confirmed that the addition of the silver nanoparticles into the polymer solution increases the fiber diameters. The result of the mechanical test of the yarns alone and used in two different forms of the knots was measured and results showed that the strength of the yarns without the knot was significantly more than that of others. The biodegradability test showed that the mechanical properties and the weight of the yarns were quickly reduced after subjecting to in vitro condition. The result of the antibacterial test indicated that the nanofiber yarns containing %3 silver nanoparticles were the most appropriate sample with a considerably antibacterial activity against both gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia Coli with inhibition zones of 8.1 and 9.5 mm, respectively; which demonstrated that silver nanoparticles retained their effectiveness after the electrospinning process. Therefore the nanofibrous yarns containing silver nanoparticles could be successfully produced by the electrospinning process with the proper antibacterial property as a candidate for the surgical sutures.     

Effects of melatonin on oocyte maturation in PCOS mouse model

The purpose of oocyte in vitro maturation is generation of mature oocytes that could support future development. Efforts have been made to enhance oocyte developmental competence by developing optimal culture conditions. The present study is conducted to determine melatonin effects on quality of polycystic ovarian syndrome (PCOS) oocytes when it has been added during in vitro maturation, and immature oocytes were cultured in defined conditioned medium with and without different melatonin concentrations. Melatonin could significantly improve nuclear maturation of PCOS oocytes (81.1% vs. 56.3%, P < 0.05 were achieved with 10^?6 mol/L concentration). Cleavage rate was significantly higher in 10^?5 mol/L concentration compared to untreated oocytes in PCOS (54% vs. 35%, respectively) and it was significantly higher with 10^?6 mol/L concentration in the control group, 55% versus 38%, compared to untreated oocytes. This study showed that melatonin has the potential to induce oocyte nuclear maturation and guarantee fertilization potential. © 2016 Japanese Society of Animal Science     

Estimating Cape hare occupancy and abundance in southern Tunisia using spotlighting data

This study outlines the importance of integrating spotlighting data and occupancy modelling to estimate the spatial occupancy, abundance and habitat preferences of Cape hares Lepus capensis in southern Tunisia. Exploring the spatial distribution pattern of this species is problematic because of its nocturnal and secretive behaviour. In order to overcome these constraints, we used spotlight surveys on equidistant points along tracks to collect presence/absence data. Using a likelihood-based approach, we estimated occupancy and relative abundance of Cape hare populations in three national parks: Sidi Toui, Bouhedma and Jbil. We also combined the three parks in a single area to represent ‘southern Tunisia’ for investigating the factors affecting its distribution pattern. Sidi Toui showed the highest occupancy and relative abundance values (88.84 ± 10.95% and 7.97 hares km^?2, respectively). Bouhedma was also recognised as high-quality hare habitat with occupancy and relative abundance values of 61.70 ± 11.70% and 2.85 hares km^?2, respectively. The lowest occupancy (49.65 ± 26.25%) and relative abundance (2.10 hares km^?2) estimates were encountered in Jbil. The combined parks model suggested that part of the distribution pattern of Cape hares can be explained by habitat quality. Spatial occupancy over southern Tunisia showed a positive relationship between its occurrence and the availability of Poaceae and Plantaginaceae.     

Cross-resistance patterns of winter wild oat (<Emphasis Type="Italic">Avena ludoviciana</Emphasis>) populations to ACCase inhibitor herbicides

The level of resistance and patterns of cross-resistance to clodinafop, sethoxydim, and pinoxaden were examined in 12 putative resistant and one susceptible populations of winter wild oat (Avena ludoviciana) collected from Fars Province, in the southwest of Iran. The responses of biomass and length of coleoptiles to the increasing dosages of the three herbicides were determined in both whole-plant and seed bioassays. In the whole-plant bioassay, all 12 putative resistant populations were found to be resistant to clodinafop with resistance ratios (R/S) ranging from 1.76 to >47.04. Most clodinafop-resistant populations exhibited low levels of cross-resistance to sethoxydim. Three highly sethoxydim-resistant populations, F2, S2, and ES4, were slightly resistant to clodinafop. Six populations (M1, M2, F2, S2, S4, and ES4) showed high cross-resistance to pinoxaden with R/S values as large as 10.73 to 40.29. A highly clodinafop-resistant population, M2, was more sensitive to pinoxaden than the susceptible population. The results of the seed bioassay resembled those obtained from the whole-plant experiment suggesting seed bioassay as an inexpensive, rapid method for screening-resistant genotypes.     

Biofumigation with Fresh Manure or Brassicaceae Residuals could be a Promising Methyl Bromide Alternative in Head Lettuce Production

The current study investigates the natural alternatives of methyl bromide on head lettuce plants grown in greenhouse. Lettuce (Lactuca sativa L.) seedlings (cv. “Big Bell”) were treated with six different MBr alternatives which are, Biofumigation with fresh cow manure, fresh chicken manure, or Brassicaceae residuals plus Bio-Compost application (using disease suppressive compost) in comparison with chemical control with one of MBr chemical alternatives (Basamid) and finally negative control (which is the standard farmer treatment). Despite that chemical control with Basamid recorded the highest survival rate, biofumigation with fresh chicken manure gave the best head length, diameter, fresh weight, dry weight, total and marketable yield. Also, highest head quality characteristics such as TSS, SPAD reading, and nitrogen content were recorded with biofumigation with fresh chicken manure. Regardless of the superiority of Biofumigation with fresh chicken manure, Biofumigation with fresh cow manure or Brassicaceae residuals showed a better vegetative growth and quality parameters than farmer treatment (control), and they had significantly less effect than chemical control treatment. Bio-Compost fortified with Trichoderma harzianum and Bacillus subtilis (disease suppressive compost) recorded survival rate similar to biofumigation treatments but were significantly lower than chemical control treatment. Bio-Compost treatment did not result in a good result regarding total and marketable yield head fresh and dry weight. There was no detected significant effect of the studied treatments on stem diameter, L?ascorbic acid (vitamin C), phosphorus and potassium content     

Impact of drought stress on yield,photosynthesis rate,and sugar alcohols contents in wheat after anthesis in semiarid region of Iran

Owing to the importance of after anthesis water deficit in Mediterranean regions (such as Iran), this study has focused on harmful impact of after anthesis drought stress on grain yield (GY), photosynthesis, and some physiological characteristics of wheat. To this aim, a factorial experiment based on randomized complete block design with three replications was used in greenhouse conditions in Razi University in Kermanshah city of Iran, during 2010–2011 growing season. Two bread wheat genotypes, “Zagros” (tolerant to drought) and “Marvdasht” (sensitive to drought) were grown in normal water supply condition (100% of field capacity) and drought stress from anthesis until maturity (50% of field capacity). The results indicated that after anthesis water deficit considerably reduced grain and biological yields, thousand grain weight (TGW) and a number of grains per spike (NGS) among different traits in genotypes. Under well-watered and drought-treated conditions, genotypes in terms of all evaluated traits had considerable variations. Water deficit caused more reduction of net photosynthesis rate (Pn), stomatal conductance (gs), relative water content (RWC) of leaf, chlorophyll a, b (Chl), and soluble proteins content in sensitive genotype; values were respectively 66.3, 73.2, 14.6, 32.1, 46.2, and 25.6%. Better performance of tolerant genotype under water deficit was associated with a great ability in production of some osmoprotectants as inositol, glycerol, and erythritol sugars. Rather adaptation of tolerant genotype to water deficit may be attributable to having maximum soluble protein, sugar alcohols, Chl content, RWC, gs and Pn in drought stress, and with respect to the results, wheat might not be able to synthesize mannitol. Transfer of gene(s) producing mannitol may cause more improvement of growth performance of wheat under stresses.     

Improving of seed quality of black seed (Nigella sativa L.) by increasing seed phosphorus content in a calcareous soil

Phosphorus (P) sufficiency during seed formation and development can affect the quality of seeds production. For increasing P content of black seed (Nigella sativa) in a calcareous soil, series of experiments were conducted in completely randomized factorial design with 4 replications at the Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2012 and 2013. The combinations of vermicompost (V), sulfur (S), and Thiobacillus bacteria (T) were mixed with a calcareous soil fertilized with 0, 30 and 60 kg P ha^?1 in pots and incubated for 63 days. At the end of incubation period, black seeds were sown in the pots and plants were grown to maturity. Results showed that S+T and V treatments were significantly increased soil available P, emergence, plant P content, seed yield and vigor of the seeds production. There were positive relationship between soil and plant P concentration with the quality of seeds production.     

Effects of municipal wastewater on soil chemical properties in cultivating turfgrass using subsurface drip irrigation

Knowing the concentrations of the nutrient elements in soils is important due to their toxic effect on humans and the environment. The aims of this study were to assess the effects of water quality, depths, and distances of lateral installation on soil chemical properties during turfgrass cultivation. A field experiment was conducted using a Split-Split-Plot design based on the randomized complete block (RCB) design with two treatments (well water and wastewater) and eight sub-treatments (45 and 60 cm distance of the laterals and 15, 20, 25, and 30 cm depths of laterals) in three replicates on a sandy loam soil, in Shahrekord, Iran. Soil samples were collected from 0 to 30 and 30 to 60 cm depth for measuring nitrate (NO₃^?), electrical conductivity (EC), and pH at the end of the experiment. During the experiment, fecal coliform was also measured at the soil surface. Results indicated that by increasing lateral distance, NO₃^? level increased in both layers. With installing laterals in deeper levels, NO₃^? concentration decreased at the beginning, then increased in the first layer, whereas in the second layer, NO₃^? concentration decreased. In addition, installing laterals in deeper depth caused an increase in soil EC in the top layer, but a decrease in the lower layer. However, the results showed that there was no significant effect of the treatments (well water and wastewater) and the sub-treatments (distance and depths of laterals) on soil pH. The results also show that with increasing laterals depth, fecal coliform level decreased at the soil surface.     

Organic and urea nitrogen fertilizer effects on rapeseed and wild mustard competition

The competitive effects of wild mustard on rapeseed with organic amendments and urea alone or combined were studied for 2 years. Treatments consisted of three Sinapis arvensis densities and fertilizer treatments of composted cattle manure, composted municipal waste, urea nitrogen, a combination CCM+urea, a combination of CMW+urea, and a control. Weed growth was stronger in urea fertilizer and with combined organic amendments than in organic amendments alone. However, application of organic amendments could increase weed competitive ability. In the first year, urea fertilizer alone and combined with organic amendments led to the greatest rapeseed yield, but in the following year, organic amendments alone were able to increase rapeseed yield approximately equal to urea fertilizer and combined with organic amendments. Application of organic amendments alone or combined with N fertilizer could be an efficient method to increase soil productivity.