Three VAM-fungi were isolated from roots of onion (Allium cepa, Liliaceae), broad bean (Vicia faba, Leguminosae) and Swiss cheese (Monstera deliciose, Araceae). Another isolate was isolated from roots of maize (Zea mays Graminae) plants raised from sterilized seeds sown in sterilized soil. All fungi have coenocytic coarse aseptate mycelium and reproduced asexually by sporangia and sporangiospores. Chlamydospores with different sizes were produced also by all fungi. Chlamydospores were formed apically and/or intercalary, either singly and/or in chains. Fungal growths on barely-sand medium and suspensions of sporangiospores (obtained from cultures grown on solid medium) were used for inoculating sterilized soil (at different levels) 7 days before and after sowing, respectively. Maize (Zea maize) seedlings showed significant improvement in their growth when grown in sterilized soil inoculated by these isolated fungi. However rate of growth improvement was quite varied and depended on source of fungal isolate and its inoculum level. Onion-isolate was more effective at the lowest inoculum level and this trend was completely reversed in Swiss cheese isolate. Broad bean-isolate gave the best results at the intermediate inoculum levels. Roots of maize plants raised in soils inoculated with fungal materials showed structures characterizing mycorrhizal infections i.e. inter- and intracellularly aseptate hyphae, chlamydospores, arbuscules and vesicles. These findings are innovative and reported herein for the first time. |
