اسم المؤلف:
هدى محمد كاظم ديوان
اسم المشرف:
بتول زينل علي
المستخلص:
استهدفت الدراسة الحالية عزل وتشخيص الفطريات المستنبتة في اوراق نبات الاس Myrtus communis واختبار فعاليتها المضادة للاحياء المجهرية وفعاليتها الانزيمية. - اظهرت نتائج عزل الفطريات المستنبتة في 500 قطعة اوراق للحصول على عدد كلي للعزلات مساويا الى 99 عزلة ف | The present study was aimed to isolate and identify endophytic fungi from leaves of myrtle Myrtus communisand study their antimicrobial and enzymatic activities. - Results of fungal isolation from 500 leaves fragments revealed isolation of 99 endophytic fungi represented a total colonization frequency (CF) of 20.4%. These fungi were related to 23 species or isolates, where Aspergillus spp. prevailed over all others (11 species) with CF of 14% for all Aspergilli, Aspergillusniger and Aspergillusflavus showed the highest CF 7.2% and 3% respectively, other Aspergilli represented Aspergillusparvulus (CF 1.6%), Aspergilluscandidus (0.4%), Aspergillusraperi, Aspergillusclavatus, Aspergillusglaucus, Aspergillusornatus, Aspergillussclerotioniger, Aspergillusterreus and Aspergilluswentii were all showed CF of 0.2%.Other isolates fungi from leaves fragments were four morphologically different isolates of Penicillium with 0.4% CF for each. Additionaly, isolates of Cladosporium sp. (2%) and Cladosporiumcladosporoides (0.4%), as well as Cunninghamella sp., Drechsleraaustraliensis, Alternariaraphani, which showed 0.2% CF for each, Paecilomyces variotii (0.6|%), and different isolates of sterile fungi (White and Hyaline colonies) were also obtained. - Study the antagonistic activity of isolated endophytes using dual culture method against five plant pathogenic fungi(Fusarium oxysporum, Fusarium graminearum, Fusarium sp., Macrophomina phaseolinaandRhizoctonia solani)taking into account the percentage of inhibition of pathogenic fungi, results revealed variation of antagonistic activities between endophytes and pathogens. Different cases of antagonism were also appeared ranged from mycoparasitism of the endophytes on pathogens or vice versa, to competition between the two fungi and to the appearance of inhibition zone between them, this result may indicates the affinity of using some isolated endophytes in biological control applications against or controling fungal plant diseases. - Effect of ethylacetate extracts of culture broth of active endophytes shown in the last experiment against two bactria E.coli, S.aureus and the yeast Candida albicans using disc diffusion method, where filter paper discs were imprignated with different concentrations of fungal broth extracts. Results showed variation of inhibitory activity against bacteria with different endophytes, bacteria and conc. of the extract. Regarding the effect onC.albicans and filamentous fungi, most fungal broth extracts showed no inhibitory activity against yeast and no extract as well showed inhibitory activity on filamentous fungi. These results give indication thatbroth extracts contain antibacterial compounds. - Addition of 20% crude fungal broth of some endophytes to the culture medium showed significant inhibitory activity against filamentous fungi which did not respond to broth extracts, percentage of inhibition ranged between 0 - 77.08% and maximum inhibitory activity was shown by Penicillium sp. Isolate. These results give indication that some of crude filtrates contain antifungal compounds. - Analysis of broth extracts of some endophytes using TLC technique showed the content of extract of number of UV illuminated spots isolated on TLC pates having different Rf values, Bioautography showed inhibitory activity of some of these isolated spots against E.coli, S.aureus and the Filamentous fungus F.oxysporum. - Testing the extracellular enzymes activities of isolated endophyles on solid media, enzymes included amylase, lipase, pectinase, laccase, cellulase and protease showed variation in secretion of these enzymes, as well as, no endophytes showed the affinity of secreting all tested enzymes. Results also showed the high affinity of some endpohytes to secrete enzymes that could be use in multiple important applications after separation andcharacterizationof these enzymes.
