| Research Abstract |
The symbiotic association between arbuscular mycorrhizal (AM) fungi and plant roots is widespread in nature. The positive effects of AM fungus inoculation on agricultural cropping systems have been investigated and include improved uptake of phosphorus and other nutrients, increased stress tolerance, and beneficial plant growth regulation. DNA amplification by PCR has been proposed as a technique for AM fungus detection and identification. I have examined the application of PCR-DGGE (Denaturing Gradient Gel Electrophoresis) analysis to the study of AM fungal community structure colonizing plant root in this research. Five kinds of AM fungal DNA (Glomus etunicatum, Glomus mosseae, Gigaspora margarita, Gigaspora rosea, Acaulospora longura) were isolated from each spore, while DNA of Fusarium sp. and Mortieralla alpina were isolated from each mycelia. Spore was crushed and its DNA was extracted by use of the freeze-thaw method. This crude extract was used as template for PCR. A nested PCR strategy was employed to amplify a 500-bp region of the 18SrDNA from fungal isolates. PCR products from fungal isolates were subjected to DGGE analysis to examine the variation seen between different fungal taxa. DGGE of the 18SrDNA fragments could resolve species differences from most of fungi used, but was unable to discriminate between G. etunicatum and Gi. margarita. We suggest that PCR- DGGE analysis is a good approach for investigating AM fungal community structure.
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