Stachybotrys elegans (Pidopl.) W. Gams is a destructive mycoparasite of the soilborne plant pathogen Rhizoctonia solani. It colonizes effectively all types of cells of R. solani, and is considered as an effective biological control agent (BCA). Monitoring the presence of this mycoparasite in the field trials requires the development of a reliable and sensitive diagnostic assay that is able to detect and differentiate the BCA from their target host. To achieve this, designed SCAR (sequenced characterized amplified regions) primers designated as SE-13F and SE-13R were generated from informative RAPD markers. They were tested in conventional PCR assays alone or in conjunction with the recently developed SCAR primers (SBU-177/336) designed for Rhizoctonia solani (Kuhn) on several types of DNA. These included DNA extracted from pure cultures, co-cultures of the BCA and the pathogen, plant tissue and several types of soils inoculated with both the BCA and the pathogen. Irrespective of the type of the biological samples from which the DNA was extracted, the primers SE-13F/SE-13R successfully amplified only S. elegans. No cross-reaction was observed when the primers were used to amplify DNA of other fungi, bacteria and plant tissues. Likewise, the primer pair SBU-177/336 detected only its target organism, i.e., R. solani. The detection limit using these primers on amplified DNA was as little as 1 pg DNA extracted from pure cultures of S. elegans, 100 pg DNA extracted from greenhouse soil and 33 pg DNA extracted from natural soil. This work is the first report on the development of SCAR markers for the BCA, S. elegans. These molecular markers offer not only an alternative diagnostic assay to conventional detection methods, but also the possibility of being used in ecological studies.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.30766 |
| Date | January 2000 |
| Creators | Wang, Xiben, 1973- |
| Contributors | J.-Hare, Suha (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Plant Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001746297, proquestno: MQ64477, Theses scanned by UMI/ProQuest. |
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