| dc.contributor.author | Delgado, Javier Andres | |
| dc.description.abstract | Ascochyta blight is the most important disease of chickpeas in North America since the
fungal pathogen Ascochyta rabiei was introduced to this region in 1986. Ascochyta blight epidemics
can cause yield and economic losses of up to 100%. Currently available chickpea cultivars are
partially resistant to A. rabiei, and the disease is primarily managed with the aid of seed and foliar
fungicide treatment throughout the growing season. Development of resistance to highly effective
fungicides such as the quinone outside inhibitor (Qol) fungicides has therefore significantly
threatened chickpea production in the US and Canada. In this dissertation, the mutation associated
with resistance to Qol fungicides was identified in A. rabiei in North Dakota from which a quick and
accurate diagnostic assay was developed for the detection of Qol resistant isolates of A. rabiei. The
detection of Qol resistant isolates is important for designing management strategies aimed to
controlling A. rabiei in the field. Polyketide synthases (PKSs) and methyltransferases have been
associated with virulence in several fungi but these genes have not been identified or characterized
previously in A. rabiei. Therefore, a bioinformatic resource was developed for the identification of
PKS proteins from the genome of A. rabiei. This was developed using the 13-ketoacyl synthase and
acyltransferase domains from PKS proteins exclusively belonging to the fungal species and was used
to identify PKS genes from the A. rabiei genome. Several methyltransferase genes were also
identified using a similar strategy. The characterization of the identified A. rabiei PKSs and
methyltransferases was conducted to study the effect of the divalent cations present in chickpea seed extracts on the accumulation of phytotoxic compounds, vegetative growth, and conidial
production. This study provides an insight into the effect of these divalent cations on the
expression of genes that modulate biological processes that may be directly associated with
infection and colonization of the host. | en_US |
| dc.publisher | North Dakota State University | en_US |
| dc.rights | NDSU policy 190.6.2 | en_US |
| dc.title | Detection of Qol Fungicide Resistance and Genomic Analysis for Identification of Polyketide Synthases and Methyltransferases in Ascochyta rabiei | en_US |
| dc.type | Dissertation | en_US |
| dc.date.accessioned | 2023-12-26T17:12:59Z | |
| dc.date.available | 2023-12-26T17:12:59Z | |
| dc.date.issued | 2011 | |
| dc.identifier.uri | https://hdl.handle.net/10365/33453 | |
| dc.subject.lcsh | Chickpea -- Diseases and pests -- Control. | en_US |
| dc.subject.lcsh | Ascochyta rabiei -- Control. | en_US |
| dc.subject.lcsh | Chickpea ascochyta blight. | en_US |
| dc.rights.uri | https://www.ndsu.edu/fileadmin/policy/190.pdf | en_US |
| ndsu.degree | Doctor of Philosophy (PhD) | en_US |
| ndsu.college | Agriculture, Food Systems and Natural Resources | en_US |
| ndsu.department | Plant Pathology | en_US |
| ndsu.program | Plant Pathology | en_US |
| ndsu.advisor | Goswami, Rubella S. | |
| ndsu.advisor | Markell, Samuel G. | |
