Open Collections

Kahl, Dieter

University of British Columbia

The first data chapter of this research presents a novel approach for identifying potential insect vectors of circulative plant viruses, significantly reducing time-to-results and the resource costs associated with greenhouse transmission experiments. This artificial transmission protocol using a buffered sucrose solution as the virus recipient in place of a living plant, also eliminates plant-to-plant variation in susceptibility to infection, allowing assessment of virus-insect compatibility required for successful transmission of persistent viruses. To validate this approach, species of hemipteran insects, including leafhoppers, froghoppers, aphids, sharpshooters, and treehoppers, were subjected to the artificial feeding system to determine their ability to vector Grapevine red blotch virus (GRBV). Test insects were allowed to feed on a potted grapevine infected with GRBV for three days and then transferred to tubes containing the sucrose solution partitioned by a thinly stretched Parafilm membrane. After three days of feeding through the membrane, viruliferous test insects were stored for species identification and the sucrose solutions were tested by polymerase chain reaction for the presence of GRBV DNA. Of all the insects tested (n = 393), only nine treehoppers from two different species successfully transmitted GRBV to the sucrose solutions, indicating a high-likelihood of vector capability to plants, to be validated by greenhouse or field experiments. The second data chapter presents research that investigated GRBV titres from several grapevine tissues, including roots, buds, cortical scrapings, and leaves, at varying distances from the cordons, and at different times during the growing season and winter dormancy. Two common nucleic acid extraction techniques were compared, a low cost high-throughput nucleic acid extraction method (GES) and a DNA column purification method. Ideal combinations of sampling parameters were determined for summer and winter diagnostics. In dormant samples, cortical scrapings yielded the highest GRBV titres and produced no false-negatives, and basal leaves yielded high GRBV titres throughout the summer months with only one false-negative on the earliest sample date. These two tissues provide the best samples for reliable and reproducible GRBV diagnostics. The crude GES and DNA column purification methods performed comparably well for binary diagnostics, however the GES method performed poorly in quantitative analysis.

Text

2021-08-01

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/78480

Biology

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/