SummaryInfection with endophytic fungi (Acremonium spp.) was detected in wild populations of Lolium spp. from 15 of 20 European countries. Of 523 populations examined, 38% contained no infection, 48% contained 1–50% infection and 14% contained 51–100% infection. Level of infection was slightly but significantly associated with abundance of Lolium in the sward.For data from France, significant correlations were obtained between level of infection and five climate variables; the highest correlations were with evapotranspiration (0.66, P < 0.001) and water supply deficit (‐0.66, P < 0.001). A model established using multiple regression analysis and incorporating five climatic variables, accounted for 56% of total variation; water supply deficit alone accounted for 43%. These climatic variables were shown by geostatistical analysis to account for a spatial structure in infection level. Groups of Lolium populations with a high level of infection were located mostly in Mediterranean regions, where stress from summer drought is common.
The optimal conditions required for chitinase production from Bacillus licheniformis B307 strain, obtained from Syrian soil, were studied. Optimization experiments were carried out under submerged fermentation conditions, and colloidal chitin was the source of carbon. Luria broth medium supplied with 0.5% colloidal chitin was the optimum medium for chitinase production. The maximum chitinase yield was obtained at 30 C, pH6, incubation time 14 days, and 150 rpm. The optimum chitinase activity was achieved at 60 C and pH6. The chitinase activity with unmodified medium was 1.9 U/mL which then enhanced about eight folds to reach 14.2 U/mL under optimized submerged fermentation conditions. An extracellular chitinase of Bacillus licheniformis B307 was partially purified using ammonium sulfate precipitation followed by concentration with various sizes of concentrator tubes. The chitinase was partially purified 8.24 fold and specific enzyme activity increased 2.08 fold (2 U/mg). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of partial purified chitinase exhibited a molecular weight (M r ) near to 36 and 42kDa. These results make it possible to invest in this strain to produce chitinase to be used as antifungal, food additives and other applications.
Maize is the third most important cereal after wheat and barley in Syria. Maize plants are attacked by several Fusarium species causing mainly stalk and ear rot of maize which poses a major impact worldwide. Identification of Fusarium species is important for disease control and for assessment of exposure risk to mycotoxines. To identify Fusarium species attacking maize in Syria, a total of 32 Fusarium isolates were recovered from maize ears collected from four different geographical regions, mainly from Ghouta surrounding Damascus. Fusarium isolates were identified based on morphology and on partial DNA sequencing of the TEF1‐α and rDNA/ITS genes. The majority (26 of 32) of these isolates was identified as F. verticillioides (subdivided into four groups), whereas three isolates turned out to be F. thapsinum, F. equiseti and F. andiyazi. The remaining three isolates were close to F. andiyazi, although further investigation is needed to confirm whether they represent a yet undescribed species. Furthermore, our results showed that sequencing the TEF1‐α gene is much more informative than sequencing of the rDNA/ITS region for Fusarium identification at the species level. PCR analysis showed that only F. verticillioides isolates were potentially fumonisin producers and that only the F. equiseti isolate was potentially trichotecene producer. This is the first report on Fusarium thapsinum, F. equiseti and F. andiyazi attacking maize in Syria.
Ins ti ti4 r Nu tiona 1 de la Recli e rcIi e A g ronom iq u r , Stri t ion d 'A i n r'lio ru tion des Pluiites, 234 avenue du Brk:rt, Frunc e (Summary Poaceae of subfamily Festucoideae frequently harbour endophytic, symbiotic fungi in their aerial parts. Isolations were made from 21 different species of Poaceae, belonging mainly to the genera Lolium and Festuca. Pure cultures of 45 fungal isolates were obtained. Morphology, isozyme and molecular analysis showed the presence of three groups of endophytes. Most of the isolates could be accommodated with the previously described species of Neotyhodium and Epichloe (the e-endophytes). Two new endophytes isolated from Koeleria cristata and Melica ciliata were shown to belong to this group. Gliocladiutn-like and Phialophot-(1-like isolates were obtained from Loliutn pereiirze and Festuca giganteit respectively (the p-endophytes). Nine isolates especially those from annual Loliiiin produced rod-like conidia. These isolates belong to Ac~retizotziurti semi4 srricto and are morphologically similar to Acremoniutn clzilense.
Fifteen isolates of fungal endophytes of grasses were studied for their ability to metabolize different sources of carbon and nitrogen. These endophytes had been isolated from 12 different species of Poaceae and included Clavicipitaceae with or without a teleomorph (genera Epichloë and Neotyphodium, respectively) and species belonging to the genus Acremonium sensu stricto (Acremonium chilense-like). Pectin and cellulose as carbon sources and tryptophan and methionine as nitrogen sources appeared to support poorly the growth of most isolates. Hexoses, disaccharides, complex nitrogen sources, asparagine, and glutamine supported growth of all isolates. The isolates of genus Neotyphodium were characterized by limited growth whatever the substrate, the inhibition of their growth by high concentrations of glucose and fructose, and their inability to assimilate pentoses (xylose, arabinose) and nitrates. The isolates of genus Epichloë showed better growth than those of the previous group and their growth was not inhibited by high concentrations of glucose, but they were also unable to use pentoses. The Acremonium chilense-like isolates showed rapid growth and were distinguished by their ability to use the pentoses and nitrates. In contrast, they showed relatively poor growth on methionine and alanine as nitrogen sources. They showed the most rapid growth on high concentrations of glucose or fructose.Key words: carbon sources, nitrogen sources, Neotyphodium, Epichloë, Acremonium, grass endophytes.
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