Primary Productivity and Water Use of the Perennial Grass, Cenchrus Ciliaris, in Arid Environments

Cenchrus ciliaris is a perennial grass that may be suitable for the restoration of Rhanterium steppes (Chaieb et al., 1991). In this study, four Cenchrus ciliaris accessions from Tunisia from a range of climate and soil conditions, likely to vary in their adaptation to drought, were evaluated for productivity, rainuse-efficiency and reproductive output at Sfax in southern Tunisia. The suitability of these accessions for the restoration of Rhanterium steppes is considered

Genomic DNA extraction method from pearl millet (Pennisetum glaucum) leaves

DNA extraction is difficult in a variety of plants because of the presence of metabolites that interfere with DNA isolation procedures and downstream applications such as DNA restriction, amplification, and cloning. Here we describe a modified procedure based on the hexadecyltrimethylammonium bromide (CTAB) method to isolate DNA from tissues containing high levels of polysaccharides. The procedure is applicable to both dry and fresh leaves of Pennisetum glaucum. This modified CTAB (2%) protocol include the use of 1.4 M NaCl, 1% polyvinylpyrrolidone (PVP), 1% &#946-mercaptoethanol and 100% ethanol in the extraction as well as reducing the centrifugation times during the separation and precipitation of the DNA. This method solved the problems of DNA degradation, contamination, and low yield due to binding and/or coprecipitation with starches and polysaccharides. The isolated DNA proved amenable to PCR amplification and restriction digestion. The technique is fast, reproducible, and can be applied for SSR-PCR markers identification.Key words:Pennisetum glaucum, genomic DNA isolation, leaves. African Journal of Biotechnology Vol. 4 (8), pp. 862-86

The State of the Art of the Tunisian Apidae Fauna (Hymenoptera: Anthophila)

Based on a review of the available literature, the state of the art and a checklist of the fauna of the Apidae family of Tunisia is presented. The first list of the species of the family is given. 184 species and subspecies belonging to 19 genera, 12 tribes and three subfamilies were listed. Distribution of recorded taxa from Tunisia and from the world is provided. Apinae is the subfamily with the highest species richness with 89 species. Nomada has the highest number of species represented by 62 taxa. The Tunisian East center is the least species-diversified regions with only 16 species and subspecies reported so far. Five species are endemic to Tunisian fauna. Eight Nomada and one Anthophora species were collected from Tunisia, but their identity should be re-confirmed. The presence of Thyreomelecta sibirica (Radoszkowski, 1893) in Tunisia is doubtful and a re-examination and confirmation are needed

Biotic potential of an exotic date palm pest specie: Oryctes agamemnon (Coleoptera: Scarabaeidae)

In Tunisia, particularly in southern regions, the culture of date palms plays an important role, both at socioeconomic and ecological levels. In spite of its importance, this agro-system is still threatened by many species of insects and diseases. Among these phytosanitary problems figure the exotic pest Oryctes agamemnon. This insect causes severe damage on palm tree mainly on the collar and the root system. The aim of this work is to study some parameters of the biotic potential of the insect.  A number of ten couples were used in this survey. Follow-up of the experiment under the following conditions (Relative humidity = 40 +/- 6%, Temperature = 28 ° C +/- 2 ° C and a photoperiod: 16/8) allowed to study the reproductive potential, the larval survival rate and the adult lifetime.  The follow-up of the experiment shows that the average pre-oviposition period and the average post-oviposition period are 25.3 ± 9.85 and 7.3 ± 5.39 days, respectively. The developmental cycle comprises, the egg, 3 larval stages L1, L2 and L3, prenymph and nymph respectively lasted 13,742 ± 2,011 days, 26,591 ± 3,142 days, 43,361 ± 3,237 days, 137,047 ± 6,132 days, 7,487 ± 0,909 days and 21,390 ± 2,655 days. Survival rates for the various stages ranged from 83.631 to 93.886%. Adults lived on average 55.18 days for males and 60 days for females. The average number of eggs laid per female was 28.7 ± 17.13 with an average fertility rate of 81.184%

Vegetation Restoration Patterns after Rangeland Enclosure in Arid Tunisia

In Tunisia arid regions, the increase in the rural populat-ion density, (Le Floc’h et al. 1999) has intensified human pressure on natural resources through ‘‘disturbances’’ such as grazing and wood harvesting, land clearing and ploughing, which largely depend on the annual rainfall. About 10% of the steppe area has been taken over by agriculture, shrinking perennial plant cover and a highly degraded vegetation class (Hanafi and Jauffret 2008). This work assesses the vegetation restoration patterns on a protected agricultural field in Tunisian arid rangeland after 15 years of enclosure and protection against plowing

Chemical composition and biological activities of Salvia officinalis essential oil from Tunisia

The aim of this study is to evaluate the chemical composition, antioxidant, antimicrobial, insecticidal and allelopa- thic activities of Tunisia Salvia officinalis essential oil (SoEO). The SoEO was characterized by the presence of 49 components with camphor (25.14 %), α-thujone (18.83 %), 1,8-cineole (14.14 %), viridiflorol (7.98 %), β-thu- jone (4.46 %) and β-caryophyllene (3.30 %) as the major components, determined by gas chromatography-mass spectrometry. The level of antioxidant activity, determined by complementary tests, namely 2,2-diphenyl-1-pic- rylhydrazyl radical-scavenging (IC50= 6.7 mg/mL), linoleic acid peroxidation (IC50= 9.6 mg/mL) and ferric reduc- ing assays (IC50= 28.4 mg/mL), was relatively moderate. The SoEO was also screened for its antimicrobial activity. Good to moderate inhibitions were recorded for most of tested microorganisms. It also exhibited important insec- ticidal activity against Spodoptera littoralis larvae and Tribolium castaneum adults with LC50 values of 55.99 and 97.43 µl/L air, respectively. The effect of the SoEO on seeds germination and growth showed different activities against radical and hypocotyl elongation of the tested species. These results suggest the potential use of the SoEO as natural antimicrobial preservative in cosmetic, pharmaceutical industry and in pest management