Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most important diseases of wheat in humid and warm areas. It reduces yield and seed quality significantly. Knowledge on fungal infection of wheat spikelets is essential in effective control of FHB disease. Adult plants of the cultivar FALAT and the line ERN92–4 were inoculated at anthesis stage by injection of 10μl spore suspension at concentration of 5 ? 104 per ml in medial spikelets using point inoculation method. The number of infected spikelets was counted 7, 14, 21 and 28?days post inoculation (dpi). At 4, 8, 24, 48, 72, 84 and 120?h post inoculation (hpi), parts of infected spikelets were observed with light microscopy and TEM. Disease sever

The main aim of present study was to prepare chitosan (CS) and chitosan nanoparticles (CS/NPs) to evaluate their antifungal and oxidative activity. CS/NPs were prepared based on the ionic gelation of CS with tripolyphosphate (TPP) anions by using centrifugation and pH change. The obtained nanoparticles (NPs) were characterized by size and zeta potential analysis. The antifungal activity of the CS and CS/NPs were evaluated on the Fusarium graminearum, which causes Fusarium head blight (FHB) on wheat by the method of spraying on the Potato dextrose agar (PDA) medium. The Dynamic light scattering (DLS) indicated that particle diameter (z-average) was approximately 180.9???35.5–339.4???50.9 and 225.7???42.81–595.7???81.7?nm for NPs prepared

Plant Protection (PPR).

Fusarium head blight (FHB) disease caused by Fusarium graminearum is one of the most important diseases of wheat in humid and warm areas. This disease significantly reduces yield as well as seed quality. The aim of this work was to evaluate the possibility of control of FHB by chitosan (CS) and chitosan nanoparticles (CS/NPs). In vitro, the application of various concentrations of CS and CS/NPs showed significant inhibition of both radial mycelial growth and number of colonies formed against F. graminearum. The application of 1000 and 5000?ppm concentration of CS and CS/NPs produced maximum inhibition of radial mycelial growth in comparison to the control, respectively. The microscopic examination, of treated F. graminearum with the CS and

In Iran, common bunt of wheat is one of the most important diseases of wheat and using resistant varieties is the best strategy against it. In order to find resistance sources against the disease for effective breeding programs, it is critical to determine races of the pathogen. In this study, spikes infected with common bunt of wheat were collected from different farms of Khuzestan province in 2005-2006. Tilletia laevis and Tilletia caries were identified as the causal agents of the disease. Twenty selected isolates were inoculated on differential genotypes and planted under field condition. Fifteen different pathogenic races were identified in this study; L-19, L-21, and L-1 (for T. laevis) T-11, T-1, T-2 and T-31 (for T. caries). Except

During a survey in the years 1384-1386 from olive orchards in Khuzestan province, a sample of olive trees showing symptoms viz wilting, dieback and in some cases decline was collected. After washing and surface sterilization, the suspected samples were cultured on PDA medium and incubated at 25 o C. In total, 124 fungal isolates from root and crown of olive were identified including a species from Verticillium (V. dahliae with 35 isolates), three species of Fusarium (F. solani with 23 isolates),) F. equiseti with 20 isolates),(F. semitectum with 4 isolates), three species of Cylindrocarpon (C. destructans with 20 isolates),(C. didymum with 8 isolates),(C. obtosisporum with 9 isolates), and R. solani with 5 isolates that were multinucleate a

During growing seasons 2005-2007 samples of grapevine with esca symptoms were collected from different vineyards in Bojnourd (North Khorassan province). Isolation were made from affected wood tissues from branches and trunks on PDA, MEA and OA media. In this study, 64 fungi isolates were recovered and identified as Phaeoacremonium parasiticum phaeoacremonium parasiticum Subject Category: Organism Names

The polymorphism and similarity relationshipsamong 50 mating-type isolates of Ustilago maydis collectedfrom Lorestan Province were determined with random amplified polymorphic DNA (RAPD). These fungal isolates were collected from 4 corn lines. Then DNA was extracted from haploid sporidiums usingpolymerase chains reaction (PCR) and specific primers, the genome offungus were examined Molecular studies of RAPD markers by using 10-primer 10–nucleotide random primers were used. The highest multiples are established by primer opo 1 with 16 bands in isolates and the lowestones are related to opo 3 primer with 6 bands in isolates. Bands created the primers opo5a 900 based pair band in 36 isolates and there was a separated model that isolate with

Cytology of Ustialgo maydis teliospore, basidiospore and mycelium was investigated with epiflouresent microscope using both ethidium bromide and ocridin orange. Surface sterilized teliospores were cultured on PDA+ 10% dextrose medium and incubated at 25 ? C for 5 days. The results revealed that nucleus in teliospore occupied most of the inner part of its cell. Sporidia had an ellipsoid shape nucleus and by means of budding produced a secondary sporidia with degree of 35 to 45 from mother cell. Two types of hyphae were investigated in infected tissues. Some of them were dicaryotic, delicate with different shapes from lobed hyphae to finger pointed like or other kinds of swelling shapes. In dicaryotic hyphae both nuclei had a close relation a

Histopathology of fungus Ustilago maydis causal agent of common corn smut was investigated in exposure to both light and electron microscopy in cultivars SC301, SC647 and DC704 that were known before as sensitive, semiresistant and resistant cultivars, respectively. For providing fungal inoculum, mixture of teliospors were collected from Khozestan province, then cultured in CMA and PDA+ 10% dextorose media and incubated 5 days at 25 C. Fungal inoculums were inoculated under 2 different methods, injection and spray; then samples were collected and fixed 2, 4, 11 and 25 days after inoculation. 18 days after inoculation, disease symptoms were first observed in injection and then spray method. Fungal penetration in host by scanning electron mic