Effect of integrated management on Fusarium wilt progression and grain yield of chickpea in Syria

Fusarium wilt, caused by Fusarium oxysporum Schlechtend.: f. sp. ciceris (Padwick) Matuo & K. Sato, is a major production problem in many countries. A study was conducted to develop an integrated management of Fusarium wilt of chickpea using genotypes, sowing dates (January as early sowing and March/April as spring sowing) and fungicide seed treatments under natural infested plots in research plots and farmers’ fields 2007–2009 cropping seasons. In most cases, sowing date and fungicides did not affect disease parameters and seed yield. Chickpea genotypes showed significant differences in seed yield but different responses for disease parameters. Averaged over locations and seasons, the rate of disease development was higher in early (0.035 units day^?1) than spring (0.023 units day^?1) sowing. Chickpea genotypes showed different responses in affecting rate of disease development and cumulative wilt incidence in early and late sowing periods. Higher mean seed yield (1.3 t ha^?1) was recorded in early than late sowing (1.0 t ha^?1) of chickpea. The average seed yield reduction due to spring sowing ranged from 9% to 60% and highest yield losses were observed in FLIP-97–706 and Ghab-3. This study showed that integrating January sowing with genotypes having good levels of resistance for Fusarium wilt and Ascochyta blight helps farmers to narrow chickpea yield gaps in Syria.     

Histomorphometrical and stereological study of the oesophagus in the adult male Persian squirrel (Sciurus anomalus)

The Persian squirrel (Sciurus anomalus) is habitat in the Middle East countries and feed on pine acorns and other seeds. The present study was carried out to investigate the histological and volumetric features of the oesophagus in Persian squirrels. Five adult male Persian squirrels were included in the study. The cervical, thoracic and abdominal oesophagus of all subjects were processed routinely and sectioned in a serial manner. Then, the total volume of the oesophagus and its different layers were estimated using Cavalieri's principle. Histological assessment revealed a non‐keratinized stratified squamous epithelium lining the mucosa. No glands were seen in the lamina propria and submucosa. Lamina muscularis was present as a distinct layer of smooth muscle cells separating the lamina propria from the tunica submucosa. The tunica muscularis consisted of two distinct layers of striated muscle fibres: inner circular and outer longitudinal that was intermingled with few scattered smooth muscle fibres especially in the abdominal region. The thoracic region contained more amount of the lamina muscularis and tunica muscularis in comparison to the cervical or abdominal regions. The obtained results revealed that the histological structure of the Persian squirrel oesophagus has differences and similarities with other rodents and even with other species of squirrel. These findings would be useful to improve the knowledge in the areas of histological structure of the rodent digestive system.     

Comparative Study of Immunological and Structural Properties of Two Recombinant Vaccine Candidates against Botulinum Neurotoxin Type E

Background

Recently, botulinum neurotoxin (BoNT)-derived recombinant proteins have been suggested as potential botulism vaccines. Here, with concentrating on BoNT type E (BoNT/E), we studied two of these binding domain-based recombinant proteins: a multivalent chimer protein, which is composed of BoNT serotypes A, B and E binding subdomains, and a monovalent recombinant protein, which contains 93 amino acid residues from recombinant C-terminal heavy chain of BoNT/E (rBoNT/E-HCC). Both proteins have an identical region (48 aa) that contains one of the most important BoNT/E epitopes (YLTHMRD sequence).

Methods

The recombinant protein efficiency in antibody production, their structural differences, and their BoNT/E-epitope location were compared by using ELISA, circular dichroism, computational modeling, and hydrophobicity predictions.

Results

Immunological studies indicated that the antibody yield against rBoNT/E-HCC was higher than chimer protein. Cross ELISA confirmed that the antibodies against the chimer protein recognized rBoNT/E-HCC more efficiently. However, both antibody groups (anti-chimer and anti-rBoNT/E-HCC antibodies) were able to recognize other proteins. Structural studies with circular dichroism showed that chimer proteins have slightly more secondary structures than rBoNT/E-HCC.

Conclusion

The immunological results suggested that the above-mentioned identical region in rBoNT/E-HCC is more exposed. Circular dichroism, computational protein modeling and hydrophobicity predictions indicated a more exposed location for the identical region in rBoNT/E-HCC than the chimer protein, which is strongly in agreement with immunological results. Iran. Biomed. Key Words: Botulinum neurotoxin type E (BoNT/E), Cross ELISA, circular dichroism, Computational modeling, recombinant vaccine-candidates     

Control of volunteer cereals with post-emergence herbicides in maize (Zea mays L.)

Volunteer winter cereals are found sporadically in maize (Zea mays L.) fields across southern Ontario. Seven field trials were conducted over a two-year period (2006 and 2007) at four locations to determine the efficacy of five acetolactate synthase (ALS)-inhibiting herbicides for the control of volunteer cereals applied at two post-emergence application timings (2–4 and 4–7 maize leaf tips). The volunteer cereals were a hard red winter wheat (Triticum aestivum L.) (‘Hyland AC Morley’), soft red winter wheat (‘Pioneer 25R47’), soft white winter wheat (‘Pioneer 25W41’), and a autumn rye (Secale cereale L.) (‘FR’) cultivar. Volunteer cereal competition in maize resulted in a yield reduction of up to 44%. Foramsulfuron, nicosulfuron, nicosulfuron/rimsulfuron provided greater than 70% control of the volunteer cereals at 56 days after treatment (DAT), while primisulfuron and rimsulfuron provided greater than 60% control. Volunteer cereal control with early and late application was greater than 82 and 61%, respectively. Hard red winter wheat was the most sensitive to the ALS-inhibiting herbicides with control of 84–93%. Soft red and soft white winter wheat cultivars were intermediate in sensitivity with control of 76–87%, while autumn rye was the least sensitive with control of at 56–71% control at 56 DAT. Maize yields were improved when volunteer cereals were controlled with the use of herbicides compared to the weedy control, but were lower than the weed-free control. Early herbicide application resulted in improved control of volunteer cereals and higher maize yield.     

Comparison of rapid diagnostic tests to detect <Emphasis Type="Italic">Mycobacterium avium</Emphasis> subsp. <Emphasis Type="Italic">paratuberculosis</Emphasis> disseminated infection in bovine liver

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne’s disease, a chronic enteritis in cattle and other domestic and wild ruminants. The presence of MAP in tissues other than intestines and associated lymph nodes, such as meat and liver, is a potential public health concern. In the present study, the relationship between the results of rapid diagnostic tests of the Johne’s disease, such as serum ELISA, rectal scraping PCR, and acid-fast staining, and the presence of MAP in liver was evaluated. Blood, liver, and rectal scraping samples were collected from 200 slaughtered cattle with unknown Johne’s disease status. ELISA was performed to determine the MAP antibody activity in the serum. Acid-fast staining was performed on rectal scraping samples, and PCR was performed on rectal scraping and liver samples. PCR-positive liver samples were used for mycobacterial culture. Overall, the results of this study demonstrated that MAP can be detected and cultured from liver of slaughtered cattle and rapid diagnostic tests of Johne’s disease have limited value in detecting cattle with MAP infection in liver. These findings show that the presence of MAP in liver tissue may occur in cows with negative results for rapid diagnostic tests and vice versa. Hence, liver might represent another possible risk of human exposure to MAP. Given concerns about a potential zoonotic role for MAP, these results show the necessity to find new methods for detecting cattle with MAP disseminated infection.     

Analysis of the effect of ozone on soybean in the Mediterranean region: I. The consequences on crop-water status

This study was carried out over three successive years (2003–2004–2005) in the southern Mediterranean region of Europe. Soybean plants were subjected to well-watered and water-stress conditions, and three levels of ozone (zero, low and high) in open top chambers (OTC) during the growing seasons.

The paper has four objectives: (i) to reproduce in OTCs the ozone concentrations actually observed in the field; (ii) to analyze the effect of ozone on well-watered crops by comparing a “control” (OTC ozone filtered treatment) with two ozone levels (at the end of the soybean growing seasons accumulated AOT40 values were 3400 and 9000 ppb h for low and high ozone treatments, respectively); observations were carried out both at leaf scale (stomatal conductance) and at canopy scale (determination of daily evapotranspiration, AET); (iii) to take into consideration the effect of drought, where the leaf and canopy scale observations were also implemented on water-stressed crops; and (iv) to analyze and verify the reliability of the ozone exposure–plant response relationship.

In well-watered conditions, an increase in ozone concentration levels reduced stomatal conductance and AET. Reductions in AET were 14% and 28% at low and high ozone levels, respectively, as compared to the control treatment. Hence, the results of daily AET were consistent with stomatal conductance results.

In water stress conditions, on the contrary, an increase in ozone had no effect on stomatal conductance and AET.

During the 3-year study, significant relationships were found between AOT40 and relative (low or high to control ozone treatment) values of stomatal conductance and AET in well-watered conditions. The reliability observed for these relationships suggest that they will be useful in soybean growth and yield-prediction models.     

Leaf type is not associated with ascochyta blight disease in chickpea (Cicer arietinum L.)

The three major leaf types in chickpea are normal compound leaf, simple leaf and multipinnate. Simple leaf types are less commonly cultivated worldwide and are often reputed to be susceptible to ascochyta blight disease, whereas other leaf types range from resistant to susceptible. This study determined the association between host plant resistance to ascochyta blight and different leaf types in segregating populations derived from crosses between disease resistant and susceptible chickpea genotypes. In addition, the inheritance of disease resistance and leaf type was investigated in intraspecific progeny derived from crosses between two resistant genotypes with normal leaf type (ICC 3996 and Almaz), one susceptible simple leaf type (Kimberley Large) and one susceptible multipinnate leaf type (24 B-Isoline). Our results showed that, in these segregating populations, susceptibility to ascochyta blight was not linked to multipinnate or simple leaf types; resistance to ascochyta blight depended more on genetic background than leaf shape; leaf type was controlled by two genes with a dihybrid supplementary gene action; normal leaf type was dominant over other leaf types; and inheritance of ascochyta blight resistance was controlled by two major genes, one dominant and one recessive. Since there was no linkage between ascochyta blight susceptibility and leaf type, breeding various leaf types with ascochyta blight resistance is a clear possibility. These results have significant implications for chickpea improvement, as most current extra large seeded kabuli varieties have a simple leaf type.     

Productivity and water use efficiency of sweet sorghum as affected by soil water deficit occurring at different vegetative growth stages

The growth and production of sweet sorghum [Sorghum bicolor (L.) Moench] crops under semi-arid conditions in the Mediterranean environment of southern Italy are constrained by water stress. The effects of temporary water stress on growth and productivity of sweet sorghum were studied during three seasons at Rutigliano (Bari, Italy). The aim of this research was to evaluate the sensitivity of phenological stages subjected to the same water deficit. In a preliminary study it was observed that stomata closed when pre-dawn leaf water potential (Ψ_b) became lower than −0.4 MPa. This criterion was used in monitoring plant water status in three different plots: one never stressed and two stressed at different phenological stages (‘leaf’ and ‘stem’) when mainly leaves or stems were growing, respectively. An evaluation of the sensitivity of phenological stages subjected to identical water stress was obtained by comparing the above-ground biomass and WUE of drought crops with those of the well-irrigated crop (up to 32.5 t ha⁻¹ of dry matter and 5.7 g kg⁻¹). The sensitivity was greatest at the early stage (‘leaf’), when a temporary soil water stress reduced the biomass production by up to 30% with respect to the control and WUE was 4.8 g kg⁻¹ (average of three seasons). These results help quantify the effects of water constraints on sweet sorghum productivity. An irrigation strategy based on phenological stage sensitivity is suggested.     

Chemometrics Approaches to Monitoring of Biogenic Amines Changes in Three Fish Species

The biogenic amine contents in fillets of three freshwater fish of kutum (Rutilus frisii), common carp (Cyprinus carpio), and Caspian salmon (Salmon caspius) were monitored during storage at 4°C for 20 days. The amounts of biogenic amines were determined at regular intervals using high performance liquid chromatography after derivatization with benzoyl chloride. Significant differences in the levels of selected biogenic amines among the fish samples were found (p < 0.05) during storage times. While the amount of putrescine, cadaverine, histamine, and tyramine in the fish fillets increased during the storage time, the changes in spermine and spermidine contents of the fish species were minor and both showed low and inverse correlations with storage time. For each of the three fish species, the sensory acceptability limit was found to be 4–8 days. The quality and biogenic amine indices of fish samples showed high correlation with storage time (r > 0.9). The principal component analysis of the results indicated that the formation of biogenic amines displays a certain behavioral pattern in all fish samples.