A. BEN ARFA

H. NAJJAA*

B. YAHIA

A. TLIG

M. NEFFATI

Arid Lands Institute, Range Ecology Laboratory, Medenine, Tunisia

Abstract - Wild Allium species with an important use in Tunisia, such as Allium ampeloprasum L. could provide interesting bioactive compounds to current diet and medical. The bioactive compound content and the antioxidants potentialities of this wild species and the influence of the environmental condition on theses characteristic have been scarcely known. In order to further asses this assumption, ten accessions originating from different bioclimatic stages of Tunisia, were compared on the basis of the bioactive compounds content and the antioxidant capacity of the edible parts of wild leek (leaves and bulbs). The total polyphenol (16.64-48.22 mg GEA/g DM), flavonoid (1.01-5.84 mg CE/g DM) and tannin (3.47-7.62 mg CE/g DM) contents and antioxidants activities (DPPH and iron chelating power) were strongly affected by above cited factors. Such variability might be of great importance in terms of the valorizing of these species as a source of naturally products, and the methods for phenolic and antioxidant production.

Keywords: accessions, bioactive compounds, DPPH and iron chelating power, Tunisia

Read more

Y. ZAOUCHI ^*

S. REZGUI

T. BETTAIEB

Institut National Agronomique de Tunisie (INAT), 1082 Tunis - Mahrajène, Tunisie

Abstract - This investigation aims to evaluate the potential of arbuscular mycorrhization to improve nutrition and growth of Jacaranda mimosifolia D.Don grown under abiotic constraints of the urban environment of Tunis city and to test the capacity of this kind of symbiose to substitute chemical fertilizers applications. The experiment was conducted using plot at the National Agronomic Institute of Tunisia located in Tunis. Plants about 1m in height are treated with indigenous mycorrhizal strains complex and a commercial product equivalent of 1kg / plant and 25 g / plant rates. For each inoculum, three fertilizer rates (15+ 9+ 12 (+2.5)) are tested using 0g, 2g and 4g corresponding to the producer recommended rate (0%, 50% and 100%). Results indicated that the infectious potential of indigenous strains is higher than strains contained within the commercial inoculum. Mycorrhization rates of the plants inoculated with indigenous mycorrhizal strains complex and those with commercial product are respectively of 43.82% and 20.86%. The combined fertilizer application and inoculation has no effect on mycorrhizal strains infectivity. Mycorrhization improves nitrogen, phosphorus, potassium and calcium woody nutrition (p = 0.01). Improvements are observed in the ability to acquire iron, magnesium and manganese by some treatments of mycorrhized Jacaranda. No effect of mycorrhization is found in terms of its zinc and sodium absorption. Jacaranda mycorrhization improves its mineral nutrition more effectively than fertilizer application adapted to the requirements of the plant. It improves its growth by increasing heights and stems and leaves dry weights.

Keywords: Arbuscular mycorrhizal fungi; mineral nutrition; growth; urban conditions; chemical fertilization.

Read more

A. Essid^1*

F. Aljane¹

A. Ferchichi^{1, 2}

¹ Laboratoire d’Aridoculture et Cultures Oasiennes Institut des Régions Arides de Médenine, Médenine 4119, Tunisie

² Institut National Agronomique de Tunisie, 43 Avenue Charles Nicolle, 1082 Cité Mahrajène, Tunis

Abstract: Leaves of twenty accessions of Tunisian caprifig (Ficus carica L.) accessions were investigated for their mineral and phenolic content. Results showed significant differences among accessions for all traits studied. Furthermore, leaves of caprifig are an important source of phenolic and mineral content. Potassium (379.05-1412.84mg/100g) is the major mineral content, followed by calcium (499.20mg/100g), magnesium (320.06mg/100g), phosphorus (175.54mg/100g), sodium (160.36mg/100g), iron (39.08mg/100g), manganese (2.54mg/100g) and zinc (1.41mg/100g). Total phenolic, flavonoid and flavonol contents ranged between 11.88-36.13mg.g-¹GAE DW; 5.88-20 mg.g-¹QE DW; 3-11.08 mg.g-¹QE DW respectively. Cluster analysis and PCA grouped accessions studied in four groups.

Keywords: Caprifig, Ficus carica L., leaves, mineral content, phenolic compound Tunisia.

Read more

W. Jendoubi^*1

K. Harbaoui²

W. Hamada^3,4

¹ Warda Jendoubi, National institute of agricultural research, laboratory of field crops,Av Hédi Karray 2080 Ariana, Tunis, Tunisia,

² Kalthoum, Harbaoui, Regional Field Crops Research Center (CRRGC), Béja-Tunisia Address: B. P. 350 Béja 9000, Tunisia, 

³ Walid Hamada, National Agronomic Institute of Tunisia, Laboratory of Genetic and Plant Breeding, 43 Av Charles Nicolle, 1082 Tunis, Tunisia.

⁴ Higher Agriculture School of Kef, Tunisia

Abstract - Salicylic acid (SA) is a plant hormone that plays an important role in induction of plant defense against a variety of biotic and abiotic stresses through morphological, physiological and biochemical mechanisms. In our study we have observed that plants grown in presence of SA show healthy appearance (Fusarium wilt symptoms) and an optimal vegetative growth compared to inoculated plants. The aimed objective of this work is to deduce if an exogenous application of salicylic acid can induce the accumulation of soluble phenolic compound in leaves of hydroponic tomato plants. This result is confirmed 24h after treatment when a gradual increase in peroxidase activity 24h after SA roots feeding were observed in roots and leaves. RT-PCR expression analysis of the gene encoding phenyl-amenia-lyase (PAL) and peroxidase (PR9) confirmed those results. The present work also showed that the PR-proteins such as glucanase (PR4), and chitinase (PR2) quickly responded to salicylic treatment and a high accumulation level of PR4 and PR2 transcripts was detected earlier at 48h and 72h post treatment through root feeding. These results suggest that SA at 200µM is safe to tomato plants and could be recommended for the stimulation of Fusarium defense which could be used biologic management programs.

Keywords: Fusarium oxysporum f.s.pradicis lycopercisi, gene expression, peroxidase, Salicylic Acid, soluble phenolic compounds, systemic acquired resistance

Read more