Seeds of bread wheat (T. aestivum), Hidhab cultivars (HD1220/3*Kal/Nac, proven from CIMMYT, selected in agricultural research station of Sétif (Algeria) in 1985), treated and untreated by (Tebuconazole, 60 g/l) and inoculated with actinomycetes isolates of indigenous plants rhizospheric soil (Ononis angustissima Lam., Astragalus gombo Coss. & Dur. and Daucus sahariensis Murb.) taken from Djebel Messaad region at M’sila-State, in southern of Algeria (Figure 1). Samples were collected in sterile cylinders, closed tightly and stored in the refrigerator at 4˚C. For each collected sample, 10 g of soil was suspended in 90 ml of physiological water (NaCl, 9 g/l), then incubated in an orbital shaker incubator at 50˚C with shaking for 30 min at 160 rpm. The suspension was serially diluted up to 10.

Several solid culture media, such as ISP2, GYEA and GYME (Table 1) in addition to streptomycin, penicillin and actidione, antibiotics were used to isolate and maintain actinomycetes isolates from selected soil samples. Culture media autoclaved at 120˚C for 2 h; glassware is sterilized at 180˚C in ventilated oven for 30 min and then microbiological manipulations performed in a laminar flow hood around a Bunsen burner.

Using the method of Pochon and Tardieux [13] three samples of 100 g to 5 cm of the top soil away from roots have been taken from the rhizosphere of 3 endemic plants zones; then putted in plastic bags and analyzed directly

ISP2 = International Streptomyces Project (Shirling and Gottlieb 1966), GYME = Gelose Yeast-Malt Extract (Kitouni 2007), GYEA = Glucose-Yeast Extract-Agar (Athalye et al. 1981), PDA = Potato dextrose agar.

or stored at 4˚C for 6 h. 10 g of each sample was ground in a sterile mortar and then sieved. 5 g were processed by 0.02 g and introduced into a container containing 50 ml of sterile distilled water. After homogenization of solution, a serie of dilutions of 10⁻¹ to 10⁻⁵ was prepared. 0.1 ml from the last three dilutions collected. Then seeded depositing 0.1 ml of each sample corresponding to the dilution 10⁻³, 10⁻⁴ and 10⁻⁵ to the spread surface of the corresponding culture medium (GYME, GYEA, ISP2) in Petri dish. Which were incubated at 28˚C for 7 to 14 days, while the boxes containing only ISP2 backgrounds, GYEA, GYME served as control and incubated in the same previous conditions [14] . Actinomycetes colonies were observed under an optical microscope (×40). They marked by their macroscopic and microscopic appearance of hard colonies; small size with a round shape surrounded by microfilaments (Figure 2(a), Figure 2(b)) and then crop diversity was thus carefully analyzed and investigated.

An aliquot of 0.1 ml of appropriate dilutions was taken and spread evenly over the surface of yeast extract-malt extract agar medium ISP2 (international streptomycetes project) [15] , supplemented with 2.5 mg/ml streptomycin and 75 mg/ml amphotericin B to inhibit bacterial and fungal contamination. Plates were incubated at 28˚C and growth development was monitored through 14 days. The isolates maintained on ISP2 medium slants at 4˚C and as a glycerol suspension 20% (v/v) at −20˚C.

Isolates morphology was examined according to the methods recommended by Shirling and Gottlieb for the International Streptomycetes Project (ISP) [15] and Bergey’s Manual of Systematic Bacteriology [16] . Visual observation using light microscopy and Gram-straining performed for further identification. Cultural characteristics of pure isolates in ISP2 media recorded after incubation for 7 to 14 days at 28˚C. Catalase and oxidase activities were determined with 3% (v/v) hydrogen peroxide solution (H₂O₂) and 1% (v/v) tetra-methyl phenylene- di-amine dihydrochloride solution (TMPDADC), respectively. The color of mycelium and soluble pigment were examined in ISP2 medium and determined by comparison with chips color of in the color harmony manual [17] . Growth at pH values (4 - 11), tolerance to NaCl (1% - 12%) and temperature range for growth (5˚C - 50˚C) was examined on ISP2 too.

The ability of actinobacteria to produce IAA was measured based on the colorimetric method described by Khamna et al., [18] and Kaur et al., [19] with some modifications. Three discs (6 mm ϕ each one) of growing actinobacteria from yeast malt agar (YMA) were inoculated into 100 ml yeast medium both containing 0.05% L-tryptophan and incubated at 28˚C on a rotary shaker at 160 rpm for seven days. Cultures were harvested and centrifuged at 1000 rpm for 10 min at 4˚C. Their action mixture, which included 2 ml of supernatant and 2 ml of “Salkowski reagent”, were incubated at 25˚C for 30 min in the dark. The absorbance of the reaction mixture was measured at 530 nm and the IAA content of the culture filtrate was quantified using a standard curve with known concentrations of pure IAA (Sigma).

Bread wheat (Triticum aestivum L.), cultivar (HD), highly susceptible to Fusarium head blight (FHB) used in this experiment. Seeds were surface sterilized by immersion in 70% ethanol for 1 min, followed by continuous agitation in a 1% sodium hypochlorite solution (NaOCl) for 5 min and rinsed with sterile distilled water. They were allowed to imbibe water overnight at room temperature. Pre-germinated seeds grown in Petri dishes, which experiments were performed in controlled environmental conditions using plant growth chamber. Seeds germinated in 150 mm diameter plastic Petri dishes each containing 20 seeds on two layers of 125 mm diameter Whitman N˚1 filter paper moistened with 8 ml Murashigue and Skoog (MS) solution [20] , in three replicates.

Actives fresh suspensions of actinomycetes isolates, approximately 1 × 10 CFU/ml in 1ml of ISP2 broth with 0.01% Tween-20 and 1 ml of F. culmorum approximately 1 × 10⁵ CFU/ml added to the seeds immediately before planting. Two seed lots were used such as seeds inoculated with F. culmorium untreated by fungicide Tubeconazole, 60 g/l without actinomycetes isolates and seeds inoculated with F. culmorum treated by fungicide Tubeconazole, 60 g/l for 7 days in the presence of actinomycetes isolates. Plants were maintained in a growth room conditions with temperature 24˚C, 16 h light/8h dark photoperiod and relative humidity of 80% and fertilized weekly with MS solution. Germination rate determined after three days after seeding and growth morpho- physiological parameters, such as the number of leaves, leaf area, root length, and chlorophyll content determined after four weeks.

Antimicrobial activities of actinomycetes isolates were evaluated by cross-striations method on ISP2. It consists in seeding actinomycetes isolates in a single line on the surface of the solid medium. After incubation at 30˚C for seven days, Target isolates were seeded perpendicular to the actinomycetes. Results were obtained after 36 to 48 h by measuring the distance between the edges of inhibition of target strain and actinomycetes isolates. Actinomycetes seeded, on PDA (Potato Dextrose Agar), the device of the Petri dish (away from the edge of the box by 3 mm), with a streak of 6mm wide. These cultures incubated at 28˚C for five days. A disk of 7 mm diameter mushroom cultivation eight days old deposed share of actinomycetes culture. The distance between mushroom and disc edge of the box is 15 mm. For each fungal isolate a control treatment was provided, with disc deposited on PDA medium without actinomycetes. Fungus colonies diameter was measured for all treatments including the control [21] . According to Williams and Willis [22] ; Aghighi et al., [23] , agar discs (6 mm ϕ) were collected from an actinomycetes culture of 14 days then putted into a Petri dish containing (PDA) medium. A washer (8 mm ϕ) of F. culmorum of 10 days old was then deposited in the center of the box and at a distance of 3 cm agar discs away. Petri dishes then incubated at 25˚C for five days. Control sample contains only a washer of F. culmorum. Daily reading is done on sample control culture.

Antifungal activity of actinomycetes isolates was underscored by cross streaks method on the ISP2 environment, agar-cylinder method and confrontation method in Petri dish [24] . The target seeds used were filamentous fungi and pathogenic bacteria. The following protocol showed the antifungal activity and biological control against plant diseases by actinomycetes isolates that produce antibiotics (Figure 2(c)). Both of 8 treated and untreated seeds of (HD) with the fungicide seeded on MS medium supplemented with 3 ml of Fusarium suspension and 3 ml of actinomycetes suspension.

We have studied actinomycetes action on Fusarium mycelium growth to assess the effectiveness of actinomycetes suspensions on Hidhab (HD) variety seeds. Spores of phytopathogenic fungus (F. colmorum) obtained by flooding a culture of 14 days on (PDA) medium incubated at 25˚C with 10 ml of sterile distilled water; conidia dislodged by scraping the medium surface with sterile Pasteur pipette. The resulting liquid was filtered through 4 layers of cotton to remove debris from the mycelium. The filtrate obtained containing spores washed twice with sterile distilled water, and spore suspension centrifuged at 1000 rpm for 5 min. Thus, pre-identified isolates of actinomycetes are streaked on Petri dish containing nutrient agar medium and incubated at 30˚C for 24 h. Cans were flooded with 10 m1 of sterile distilled water and scraped with a sterile Pasteur pipette; the recovered suspension homogenized by stirring, then spore concentration estimated using a Malassez cell and adjusted to the required concentration (108 spores/ml) by adding it to sterile distilled water [25] . It noted that we have used in this study the MS medium [20] supplemented with 0.5 g/l of 2.4, Dichlorophenoxyacetic acid. Wheat seeds disinfected by 70% alcohol for 70 seconds, and then they soaked in water for 15 min bleach followed by three successive rinses with sterile distilled water.

Measurements related to the enumeration of isolated actinomycetes and their behavior towards the culture medium used and macro-morphological characterizations, and their antagonistic activities mentioned. Data were processed by the analysis of variance, using Crop-Stat 7.2.3 software (2009), and then Newman-Keuls test at 5% probability, is used to compare treatment means.

Seed germination capacity of bread wheat (T. aestivum), Hidhab variety inoculated by actinomycetes isolates in the presence of F. culmorum showed that the percentage of both germinated seeds treated and untreated by commercial fungicide (Tebuconazole, 60 g/l) exceeds 85%, so there is a significant effect of treatment by fungicide. These results, confirm that the treatment by fungicide has a depressive effect on the pathogen and therefore a positive effect on the germination rate (Figure 3(a)).

In general, plants are grown from inoculated seeds with actinomycetes isolated and treated with commercial fungicide (Tebuconazole, 60 g/l), the number of leaves is high (6 leaves) compared to seedlings which untreated seeds (2 leaves) (Figure 3(b)). However, seedlings treated and untreated with the commercial fungicide and inoculated with D8 and D5 isolates in the presence of (F. culmorum) have developed an average leaf area 5.5 cm² and 14 cm² respectively. While plantlets seeds inoculated with AST1 isolate in the presence of the commercial fungicide, have developed a leaf area (8 cm²), and in the absence of this fungicide (17 cm²). For the D2 isolate, leaf area is 18 cm² for plantlets treated seeds and 23 cm² for those from untreated seeds (Figure 3(c)). While root length is 5 to 6.5 cm, for plantlets seed inoculated by D2, D5 and D8 isolates and treated with (Tebuconazole, 60 g/l). Seeds inoculated with AST1 isolate in the absence of fungicide reaches a 3 cm length of roots

(Figure 3(d)). The measurements for chlorophyll content of seeds inoculated by D2, D5, D8 and AST1 isolates, shows values SPAD between 0.9 to 1 for seeds treated with (Tebuconazole, 60 g/l) and between 1.1 to 1.2 for untreated seeds by Tebuconazole, 60 g/l (Figure 4).