MSpace - DSpace at UofM >
Faculty of Graduate Studies (Electronic Theses and Dissertations) >
FGS - Electronic Theses & Dissertations (Public) >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1993/4731

Title: Identification of quantitative trait loci for resistance to Sclerotinia sclerotiorum in Brassica napus
Authors: Behla, Ravneet
Supervisor: Li, Genyi (Plant Science)
Examining Committee: McVetty, Peter (Plant Science) McCallum, Brent (Biological Sciences) Selvaraj, Gopalan (University of Saskatchewan)
Graduation Date: October 2011
Keywords: Sclerotinia stem rot
Brassica napus
QTL
resistance
Issue Date: 24-Jun-2011
Abstract: Quantitative trait loci (QTL) analysis for Sclerotinia stem rot resistance was carried out in five doubled haploid (DH) populations of Brassica napus. Sclerotinia stem rot is caused by the necrotrophic fungus Sclerotinia sclerotiorum (Lib.) de Bary. Sclerotinia stem rot has worldwide occurrence and causes significant yield losses in many crop species. Several screening methods have been recommended in the literature to evaluate plant resistance to Sclerotinia stem rot. Four controlled environment based screening methods: 1) excised leaf assay, 2) cotyledon assay, 3) mycelial stem inoculation technique and 4) petiole inoculation technique compared for their ability to differentiate between plant susceptibility/resistance, their reliability and suitability for large scale screening using eight B. napus cultivars/lines of varying reaction to S. sclerotiorum. The petiole inoculation technique and the mycelium stem inoculation technique were identified as reliable methods in this study. Previously developed, five B. napus DH populations (H1, H2, H3, DH179 and DH180) segregating for resistance to Sclerotinia stem rot were used in this study. The petiole inoculation technique was used to evaluate resistance to Sclerotinia stem rot. Data on days to wilting was recorded for a two week period. Twelve plants per line were screened in each evaluation and each population was evaluated three times. Two to three day-old mycelial cultures of S. sclerotiorum isolate Canada 77 was used. QTL analyses were carried out using a LOD threshold value of 2.5 on each individual replicate and on the average of all the replicates. In the H1 population, the number of QTL detected ranged from four to six in each analysis. In the H2 population, there were three to six QTL in each analysis. There were two to six QTL in each analysis of the H3 population. In the DH179 population, the number of QTL detected ranged from three to five in each analysis. In DH180 population, the number of QTL identified varied from three to six in each analysis. A number of common QTL were found between the replicates of each population. Five common QTL were identified between these populations. The markers linked to these QTL are now available for marker assisted selection.
URI: http://hdl.handle.net/1993/4731
Appears in Collection(s):FGS - Electronic Theses & Dissertations (Public)

Files in This Item:

File Description SizeFormat
Ravneet Behla.pdf9.57 MBAdobe PDFView/Open
View Statistics

Items in MSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! MSpace Software Copyright © 2002-2010  Duraspace - Feedback