Abstract

Late Wilt disease in maize, caused by Cephalosporium maydis, is considered to be the most economically important fungal disease of maize in Egypt. The fungus is a soil borne vascular disease that affects vascular tissue by penetrating the root system and colonizing the xylem. An infection rate of up to 100% can be recorded in fields of susceptible hybrids, which can result in a yield loss of 50%. Therefore, characterizing traits and their genes that confer resistance against C. maydis is a priority in maize crop management. In this study, quantitative trait loci (QTL) of late wilt resistance were mapped by using eight F3 populations encompassing 554 lines ( five populations belongs to the stiff stalk group, while the other three belongs to the non-stiff stalk genetic group) resulting from crossings between five resistant and six susceptible inbred lines. The populations and their parents were evaluated under artificial infestation using the four Egyptian clonal lineages of the pathogen during the growing season in 2011. Variation shown in infection incidence within the populations was significant regarding disease symptoms. Parents for each of the 8 population showed high diversion in infection incidence, varied between 5% for resistant parents, while reached average of 66% for susceptible parents. QTLs were mapped on the public linkage map IBM2 constructed with 842 SNPs. Composite Interval Mapping on IBM2 linkage map identified major QTLs accounting for 1 to 58 % of the phenotypic variance, which can be candidate markers used in Marker Assisted Selection to breed for late wilt resistance in maize.

School

School of Sciences and Engineering

Department

Biotechnology Program

Degree Name

MS in Biotechnology

Graduation Date

2013

Submission Date

2013

First Advisor

Edwin Cruz-Rivera

Committee Member 1

Walid Fouad

Committee Member 2

Ahmded Moustafa

Extent

56 leaves

Document Type

Master's Thesis

Rights

The American University in Cairo grants authors of theses and dissertations a maximum embargo period of two years from the date of submission, upon request. After the embargo elapses, these documents are made available publicly. If you are the author of this thesis or dissertation, and would like to request an exceptional extension of the embargo period, please write to thesisadmin@aucegypt.edu

Institutional Review Board (IRB) Approval

Not necessary for this item

Creative Commons License

Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.

Available for download on Friday, August 02, 2999

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