Response of the tomato miner Tuta absoluta (Lepidoptera: Gelechiidae) to thirteen insecticides in semi‐natural conditions in Tunisia

Experiments on larvicide and ovicide activity of 13 insecticides in semi‐natural conditions showed a medium to low efficacy of bio‐insecticides on all instars of Tuta absoluta (Meyrick) except for Bacillus thuringiensis Berliner var. kurstaki which was distinguished by an average mortality of 72.5%. Spinosad and Spinetoram based insecticides showed high efficiency in controlling all instars of larvae with respectively an average mortality of 66.5% and 85.6%. However, this study revealed a unique ovicide effect of azadirachtin‐neem oil based insecticide with 43.8% egg mortality.     

Oxidant and antioxidant profile of hyperketonemic ewes affected by pregnancy toxemia

Background: Negative energy balance during late pregnancy in ewes is an important cause of hyperketonemia. Ketone bodies can generate superoxide radicals and cause oxidative stress and cellular dysfunction, as noted in cows with subclinical ketosis or in diabetic people. Objective: The aim of this study was to evaluate the role of hyperketonemia in initiating the process of lipid peroxidation. Methods: The study included 10 pregnant ewes (aged 3.5–6 years) with pregnancy toxemia, 10 clinically healthy pregnant ewes, and 10 clinically healthy nonpregnant ewes. Serum concentrations of β‐hydroxybutyrate (BHB), cortisol, and glucose, plasma activities of glutathione peroxidase, superoxide dismutase, and catalase, and plasma concentrations of thiobarbituric acid reactive substances (TBARS), markers of lipid peroxidation, and reduced glutathione were measured. Data from the 3 groups were statistically analyzed and compared. Results: Serum concentrations of BHB, cortisol, and TBARS were significantly higher in ewes with pregnancy toxemia when compared with concentrations in healthy pregnant and nonpregnant groups (P≤.05). In ewes with pregnancy toxemia, a strong positive correlation was found between concentrations of TBARS and BHB (r=.80; P=.002) and between concentrations of BHB and cortisol (r=.76; P=.005). Conclusions: Oxidative stress and lipid peroxidation are involved in the development and complications of pregnancy toxemia. An association between hyperketonemia and the products of lipid peroxidation has also been demonstrated, suggesting that ketosis is a risk factor in the development of lipid peroxidation and oxidative stress in ewes affected by pregnancy toxemia.     

Evaluation of two methods for the protection of tomato crops against the tomato leafminer Tuta absoluta (Meyrick) under greenhouses in Tunisia

The evaluation of two methods of plant protection in tomato crops cultivated in greenhouses against Tuta absoluta (Meyrick) in the region of Teboulba in Tunisia was performed. This study evaluated the use of insect‐proof screens alone or in combination with one sex pheromone water trap compared to a control greenhouse not equipped with either. The study confirms that the use of one sex pheromone water trap combined with insect‐proof covering of doors and aeration openings is sufficient to guarantee good crop protection. This combined control system allowed a low density of the pest (less than 2 individuals per leaf) to be maintained and a mean number of mines below 1 mine per leaf.     

Accelerated hydrolysis method to estimate the amino acid content of wheat (Triticum durum Desf.) flour using microwave irradiation

The technique of microwave-assisted acid hydrolysis was applied to wholegrain wheat (Triticum durum Desf. cv. Balcali 2000) flour in order to speed the preparation of samples for analysis. The resultant hydrolysates were chromatographed and quantified in an automated amino acid analyzer. The effect of different hydrolysis temperatures, times and sample weights was examined using flour dispersed in 6 N HCl. Within the range of values tested, the highest amino acid recoveries were generally obtained by setting the hydrolysis parameters to 150 °C, 3 h and 200 mg sample weight. These conditions struck an optimal balance between liberating amino acid residues from the wheat matrix and limiting their subsequent degradation or transformation. Compared to the traditional 24 h reflux method, the hydrolysates were prepared in dramatically less time, yet afforded comparable ninhydrin color yields. Under optimal hydrolysis conditions, the total amino acid recovery corresponded to at least 85.1% of the total protein content, indicating the efficient extraction of amino acids from the flour matrix. The findings suggest that this microwave-assisted method can be used to rapidly profile the amino acids of numerous wheat grain samples, and can be extended to the grain analysis of other cereal crops.     

Sequence analysis of the internal transcribed spacers (ITSs) region of the nuclear ribosomal DNA (nrDNA) in fig cultivars (Ficus carica L.)

Sequences of the internal transcribed spacers (ITSs) of nuclear ribosomal DNA (nrDNA) were analysed in a set of Tunisian fig (Ficus carica L.) cultivars. The size of the spacers sequences ranged from 200 to 279 bases for ITS1 and from 253 to 314 bases for ITS2. Variation of GC contents has been also observed and scored as 59–68% and 55–68% for ITS1 and ITS2, respectively. This data exhibited the presence of polymorphism among cultivars. The intra-specific variability level of the ITS sequences proved a variation both in the length and in the sequences studied. In fact, ITS1 and ITS2 sequences were considered as a useful tool to establish genetic relationships among cultivars. Our results indicate that the diversity detected among closely related genotypes supported strongly the efficiency of ITS sequences for establishing relationships between cultivars. ITS2 seems to be relatively more informative than ITS1 regarding length or GC contents. Considerable genetic diversity was observed among fig at intra and inter-cultivars levels. Two polyclonal varieties were identified. In addition, data proved that a typically continuous genetic diversity characterizes the local fig germplasm. The topology of the derived dendrogram strongly supported this assumption. In fact, genotypes are clustered independently from their geographical origin or the sex of trees suggesting a narrow genetic basis among the ecotypes studied in spite of their phenotypic distinctiveness. Implications of these results for management of fig germplasm collections are discussed.     

Direct electron paramagnetic resonance study of tobacco. 1. Manganese(ii) as a marker

Three categories of tobacco products were studied using electron paramagnetic resonance (EPR) spectroscopy: Cuban cigar brand name Montecristo, four international trademark cigarettes, and three types of Middle Eastern tobacco blends called Al-Moassal or Jurak. The Montecristo Cuban cigar is used as standard of high-quality tobacco. Mainly two EPR signals from all of the studied samples are observed: a very weak sharp EPR signal superimposed on a broad signal. The broad EPR signal is attributed to a manganese(II) complex. The intensity of the manganese(II) EPR signal is found to be related to the quality of the tobacco content. The sharp signal, which is characteristic of semiquinone radicals, is observed at room temperature, and its intensity increases drastically with temperature.     

Hot water dipping of olives (Olea europaea) for virgin oil debittering

Olives (Olea europaea L.) of the Manzanilla, Picual, and Verdial varieties harvested at the green mature stage of ripening were dipped in hot water at a range of temperatures between 60 and 72 degrees C for 3 min. Immediately after treatment, oils were physically extracted from the olives. Olive heating promotes a reduction of oil bitterness in direct relationship to the temperature used. Fruit heating at > or =60 degrees C for 3 min did not cause significant changes in acidity, UV absorption, peroxide index, and panel test score of the oils obtained but decreased its oxidative stability. Oils extracted from heated fruit showed higher concentrations of chlorophylls and carotenes and lower total phenol content.     

Comparative Analysis of Genetic Diversity in Two Tunisian Collections of Fig Cultivars Based on Random Amplified Polymorphic DNA and Inter Simple Sequence Repeats Fingerprints

This study characterized the genetic diversity of 18 Tunisian fig cultivars using random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR). Both random and ISSR primers tested generated a total of 116 RAPD and 47 ISSR markers. Considerable genetic variation was observed among fig cultivars sampled from two regional Tunisian collections with an average diversity of 4.57. RAPD and ISSR banding patterns and genetic distances values reflected the high level of diversity among the collections and lower variability between the two collections. The correlation between the RAPD and ISSR similarity matrices computed for the 153 pairwise comparisons among the 18 varieties was lower and significant. An analysis of molecular variance showed that 92% of the total genetic diversity resided within collections, whereas only 8% between collections. The results indicated that in the local fig germ plasm the information provided by RAPD and ISSR is not analogous, most likely as a consequence of the fact that the two classes of markers explore, at least in part, different portions of the genome.     

A post-mortem study of bovine fasciolosis in the Mitidja (north center of Algeria): prevalence,risk factors,and comparison of diagnostic methods

Tropical Animal Health and Production - The present study was conducted to determine the prevalence of fasciolosis and investigate the associated risk factors (sex, age, and season) in slaughtered...     

Prevalence and distribution pattern of intestinal helminths in chicken and pigeons in Aswan,Upper Egypt

Tropical Animal Health and Production - There is scarce data available on helminth infection of poultry in the region of Aswan province, Upper Egypt. A total of 276 poultry (156 baladi chickens and...