The Potential of Green Manure Mixtures to Provide Nutrients to a Subsequent Lettuce Crop

The objectives of this greenhouse experiment were to quantify the benefits of green manure (GM) diversity and to assess effect of GM on a succeeding lettuce crop. Species included barley (B), field pea (P), sunn hemp (S), and buckwheat (U). Treatments included single plantings of B and P and mixtures of B and P (BP), B, P, and S (BPS), and B, P, S, and U (BPSU). The pea GM had the highest shoot concentration of potassium, calcium, magnesium, manganese, zinc, and iron. Roots had higher concentrations of nutrients than shoots. Accumulation of nutrients in legumes was higher than in barley. The CO₂ flux from the soil suggests that the most intensive mineralization period occurred within two weeks after incorporation of GMs. The mixtures and single planting of P mixtures had a significant benefit over single planting of B regarding fresh and dry weight of the lettuce.     

Accumulation and phytoremediation of Pb,Zn, and Ag by plants growing on Koshk lead–zinc mining area,Iran

Purpose

This study investigated the extent of metal accumulation by plants colonizing a mining area in Yazd Province in Central Iran. It also investigated the suitability of these plants for phytoextraction and phytostabilization as two potential phytoremediation strategies.

Materials and methods

Plants with a high bioconcentration factor (BCF) and low translocation factor (TF) have the potential for phytostabilization, whereas plants with both BCFs and TFs >1 may be appropriate for phytoextraction. In this study, both shoots and roots of 40 plant species and associated soil samples were collected and analyzed for total concentrations of trace elements (Pb, Zn, and Ag). BCFs and TFs were calculated for each element.

Results and discussion

Nonnea persica, Achillea wilhelmsii, Erodium cicutarium, and Mentha longifolia were found to be the most suitable species for phytostabilization of Pb and Zn. Colchicum schimperi, Londesia eriantha, Lallemantia royleana, Bromus tectorum, Hordeum glaucum, and Thuspeinantha persica are the most promising species for element phytoextraction in sites slightly enriched by Ag. Ferula assa-foetida is the most suitable species for phytostabilization of the three studied metals. C. schimperi, L. eriantha, L. royleana, B. tectorum, M. longifolia, and T. persica accumulated Ag, albeit at low level.

Conclusions

Our preliminary study shows that some native plant species growing on this contaminated site may have potential for phytoremediation.

     

Role of Clostridium perfringens in causing abomasal ulcers in buffalo

In this study, the correlation between abomasal ulcers and presence of Clostridium perfringens (C. perfringens) was evaluated in 80 (50 affected and 30 non affected) randomly slaughtered buffaloes in Ahvaz slaughterhouse. Immediately after the slaughter, the abomasums was isolated and an incision was made on the wall of it. Then the abomasums were emptied and its interior was washed with water. The inner surface was examined for presence of abnormal lesion. Ulcers from affected and piece of abomasa from non affected buffaloes were cultured. Cultures were also made from contents of all samples and smears were also prepared from affected and non affected tissues. Cultures from content samples (12%) of 50 ulcerated abomasa were positive for C. perfringens while the agents were isolated from 1 content (3.3%) of non ulcerated abomasa. There was no statistical difference between presence of C. perfringens in contents and abomasal ulcers. Totally C. perfringens were isolated from ulcers of 6 (12%) ulcerated and tissues of 3 (10%) non ulcerated cases. Statistical analysis showed no correlation between presences of C. perfringens and abomasal ulcers. There was no statistical difference between sex and age of the affected animals. In conclusion C. perfringens seems not to be solely, a cause ofabomasal ulcers in buffaloes.     

Effects of ketamine‐diazepam and ketamine‐acepromazine combinations on intraocular pressure in rabbits

ObjectiveTo determine the effects of ketamine-diazepam and ketamine-acepromazine combinations on intraocular pressure (IOP) in rabbits.Study designRandomized clinical trial.AnimalsSixteen adult New Zealand white rabbits approximately one year old, weighing 2.3 ± 0.2 kg were used in this study.MethodsThe animals were randomly divided into two groups of eight each (KA and KD). The pre-treatment IOPs were recorded in both groups (T0). All rabbits in group KA received intramuscular ketamine-acepromazine (ketamine 30 mg kg^?1+ acepromazine 0.5 mg kg^?1). Ketamine-diazepam (ketamine 30 mg kg^?1 + diazepam 1 mg kg^?1) was administered intramuscularly in members of group KD. The IOP values were measured at 5 (T₅), 15 (T₁₅), and 20 (T₂₀) minutes after drug administration in both treatment groups.ResultsSignificant increases in IOP values were observed in both treatment groups at T_5, T₁₅, and T₂₀ in comparison to the baseline values. In group KA the mean ± SD IOP at T_5, T₁₅, and T₂₀ were 37 ± 13 (p < 0.001), 35 ± 4 (p < 0.001) and 34 ± 4 mmHg (p < 0.001). The post-treatment mean ± sd values in group KD were 23 ± 8 (p = 0.002), 23 ± 5 (p < 0.001) and 23 ± 6 mmHg (p = 0.001) at 5, 15, and 20 minutes respectively.Conclusion and clinical relevanceBoth ketamine-diazepam and ketamine-acepromazine combinations increased IOP after intramuscular administration in rabbits.     

The nutritional effect of Isochrysis galbana and Chaetoceros muelleri cultured with different seaweed extracts on the larval development,growth and survival of the marine shrimp,Penaeus indicus

The microalgae Isochrysis galbana and Chaetoceros muelleri were cultured with seaweed extract (SWE) from six different seaweeds and each SWE was used either as a supplement or as an alternative media to conventional f/2 medium. Microalgae cultured with only the f/2 media acted as the control treatment. I. galbana and C. muelleri were then fed to Penaeus indicus larvae, either singly or in combination, for 8 days to evaluate its nutritional quality. Shrimp larvae fed on microalgae cultured in f/2 media supplemented with SWE from Ulva lactuca or Enteromorpha intestinalis moulted faster (P < 0.05) to the second mysis stage compared with the control. Survival, total length and growth rates were better in shrimp larvae fed on microalgae previously cultured in media supplemented with SWE. In general, shrimp larvae fed microalgae cultured entirely in SWE performed equally well compared with the control. Shrimp larvae fed on mixed microalgae (I. galbana + C. muelleri) showed significantly better growth, survival and development compared with larvae on either single microalgal diet. It was concluded that microalgae cultured with SWE could be used as a low‐cost alternative media in producing live food for the hatchery production of shrimp larvae.     

Determination of antibiotic resistance pattern and virulence genes in Escherichia coli isolated from bovine with subclinical mastitis in southwest of Iran

The aims of the present study were to investigate the prevalence of some virulence genes and also determine the antimicrobial resistance pattern of E. coli isolated from bovine with subclinical mastitis. The milk of 502 cows was collected from 8 dairy herds in the southwest of Iran. Conventional biochemical tests were used for identification of E. coli at the species level. Antimicrobial susceptibility patterns of E. coli isolates were determined by disc agar diffusion method and polymerase chain reaction (PCR) was used for detection of seven virulence genes including f17A, afaE-8, afaD-8, eaeA, cnf1, cnf2, and iucD. Seventy (13.94%) isolates of E. coli were identified in 502 milk samples. The highest rate of resistance was observed against tetracycline (18.6%), while none of the isolates were resistant to streptomycin. Eight (11.5%) out of 70 E. coli isolates carried at least one of the virulence genes. The afaD-8 was the most prevalent gene detected in 5 (7.1%) isolates. The afaE-8, iucD, and eaeA were detected in 3, 3, and 2 isolates respectively. Low prevalence of virulence factors may be indicating that most of the E. coli isolates originated from the commensal flora of cows and enter to the udders via environment contamination with feces.

     

Characterization of phytoplasmas related to peanut witches’-broom and stolbur groups associated with alfalfa diseases in Iran

Journal of Plant Diseases and Protection - In the central and south eastern provinces of Iran, alfalfa plants showing phytoplasma diseases-like symptoms categorized into three major types, namely...     

Genetic variation,vegetative compatibility,and aggressiveness diversity of Diplodia bulgarica isolates from apple orchards in West Azarbaijan province of Iran

This study investigated inter-simple sequence repeat (ISSR), vegetative compatibility, and aggressiveness diversity in 101 isolates of Diplodia bulgarica recovered from apple trees displaying symptoms of canker and decline in West Azarbaijan province of Iran. Marker analyses revealed high within population diversity, low genetic differentiation, high gene flow, and sharing of multilocus genotypes (MLGs) among geographic populations. Moreover, clustering and multivariate analyses identified two highly differentiated genetic clusters with limited admixture between them. These findings may suggest that the pathogen has been introduced from two genetically divergent sources and has been moved within the region through infected materials. The large number of MLGs, low clonal fraction, and absence of a widely distributed dominant genotype may explain the occurrence of recombination in this pathogen. However, significant linkage disequilibrium in the populations and limited admixture between genetic clusters may indicate the rare occurrence of recombination in D. bulgarica populations in West Azarbaijan, and that the pathogen has not been in the province long enough to reach equilibrium. Vegetative compatibility analyses revealed the occurrence of anastomosis between nonself pairings and high vegetative compatibility group diversity within populations. All studied MLGs produced necrotic lesions on detached shoots of Red Delicious apple but differed in their aggressiveness levels. Our results provide new insights into genetic and phenotypic variation of D. bulgarica that can assist in developing management strategies. Our findings also highlight the vital need for quarantine measures and the production of healthy plant materials to prevent the introduction and spread of the pathogen in Iran.     

Resistance spectra of wheat genotypes and virulence patterns of <Emphasis Type="Italic">Mycosphaerella graminicola</Emphasis> isolates in Iran

Co-evolution of wheat and its devastating pathogen Mycosphaerella graminicola (anamorph Septoria tritici), the causal agent of septoria tritici blotch, a foliar disease of wheat, is suggested to occur in Fertile Crescent as their center of origin and, thus, interaction between pathogen virulence and host resistance is important subject to be addressed. We have investigated resistance spectra of 54 wheat genotypes including a set of differentials carrying known resistance genes and virulence patterns of 14 M. graminicola isolates at seedling stage under controlled environmental conditions. The isolates were collected in Iran from five provinces. Diversity in virulence and aggressiveness was observed among the isolates from four provinces. Isolates collected from Golestan province were virulent to all wheat genotypes from germplasm of Iran, while specific resistances were identified to the isolates from other provinces. Among wheat genotypes, cvs. Chamran, Morvarid and Hirmand had the greatest number of specific resistances as well as partial resistance. Wheat genotypes of the differential set also differed in their reactions to the isolates. Arina, Flame and TE 9111 were specifically resistant to the greatest number of isolates from different provinces. Most isolates were virulent to the other differentials such as cvs. Shafir, Estanzuela federal and Courtot indicating that extensive adaption of virulence to most of the known resistance genes (Stb) has occurred in these regions. The new sources of resistance to highly virulent isolates from Iran may also be utilized in wheat breeding programs to develop resistant cultivars against pathogen populations in other countries.