Improving spring wheat resistance to the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) by understanding the resistance mechanisms of the winter wheat Mironovskaya 808 and assessing hairs and awns as physical barriers to oviposition
| dc.contributor.author | White, Bridget | |
| dc.contributor.examiningcommittee | Lamb, Robert (Entomology) | |
| dc.contributor.examiningcommittee | McCartney, Curt (Plant Science) | |
| dc.contributor.supervisor | Costamagna, Alejandro | |
| dc.date.accessioned | 2023-09-05T16:50:13Z | |
| dc.date.available | 2023-09-05T16:50:13Z | |
| dc.date.issued | 2023-08-16 | |
| dc.date.submitted | 2023-08-16T20:58:21Z | en_US |
| dc.degree.discipline | Entomology | en_US |
| dc.degree.level | Master of Science (M.Sc.) | |
| dc.description.abstract | The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a prominent pest of spring wheat in western Canada, with larvae causing damage by feeding on the developing kernel, reducing yield and grain quality. Antibiosis, expressed through the Sm1 gene, is important in controlling wheat midge, however, larval feeding on Sm1 varieties can still reduce grain quality. Antixenosis is another type of host plant resistance that could potentially control wheat midge, primarily through plant traits that deter oviposition. To improve host plant resistance in spring wheat, laboratory and field studies were used to assess the mechanisms of resistance in a particularly resistant Sm1 variety, Mironovskaya 808, and the impact of awns and hairy glumes as physical barriers to oviposition (using SMART lines with these traits). Wheat spikes of different lines were exposed to wheat midge adults in choice cages and dissected for eggs. Field studies were conducted over two years at two locations in Manitoba to assess the percentage of midge-damaged kernels (% MDK) between the different cultivars. In addition, a doubled haploid (DH) population derived from a Roblin/ Mironovskaya 808 cross was assessed for % MDK across three growing environments to identify quantitative trait loci (QTL) for wheat midge damage. Larvae hatched on Mironovskaya 808, and dead 1st instars were found within six days of wheat midge exposure. In addition, Mironovskaya 808 had consistently low damage in the field. Genetic analysis revealed a QTL on chromosome 4B (QSm.umb-4B) that improved resistance in combination with Sm1, and on chromosome 2D (QSm.umb-2D) where the Ppd-D1 photoperiod sensitivity gene is located. Spikes with awns tended to have fewer eggs in the laboratory, however both awns and hairy glumes did not reduce damage in the field, suggesting these morphological traits do not offer resistance against wheat midge. However, four SMART lines exhibited oviposition deterrence and lower damage in the field independently of awns and hairs. Combining the deterrence traits from these SMART lines and QSm.umb-4B with the Sm1 gene could be a way to decrease damage and maintain high-quality grain, while also reducing the adaptation of wheat midge to resistant varieties. | |
| dc.description.note | October 2023 | |
| dc.identifier.uri | http://hdl.handle.net/1993/37568 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Crop protection | |
| dc.title | Improving spring wheat resistance to the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) by understanding the resistance mechanisms of the winter wheat Mironovskaya 808 and assessing hairs and awns as physical barriers to oviposition | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | yes | |
| project.funder.name | Agriculture Development Fund Saskatchewan |