Epsilon Archive for Student Projects

Abstract

Virus yellows is an increasing problem for the sugar beet industry in Europe. The disease was previously limited by effective vector control by neonicotinoids insecticides, but after they were phased out in the EU, there is a growing need for resistant and tolerant sugar beet cultivars. The global seed producer DLF Beet Seed is therefore evaluating a broad genetic material for resistance and tolerance and is
working extensively with breeding new resistant/tolerant varieties. Beet mild yellowing virus (BMYV, genus Polerovirus, family Luteoviridae) is one of the viruses causing yellowing in sugar beets. BMYV is naturally transmitted by the aphid vector Myzus persicae and mechanical inoculation of the virus is not possible,
as BMYV is limited to vascular tissue in the plant. DLF Beet Seed is therefore using aphids as vectors in the resistance and tolerance screening. However, a practical alternative to aphid transmission is the use of agroinfection, which is
Agrobacterium-mediated transmission of a full-length cDNA clone of the virus.
The agroinfection method offers less expensive screening and enables resistance evaluation to virus strains not presents in Sweden. Thus, this thesis is aimed to commence the development of the agroinfection method at DLF’s station for
breeding and development in Landskrona. First, the GFP and GUS reporter gene systems were evaluated to allow optimization of the argoinfection method, where the GUS reporter gene system was found to be suitable to work with. Secondly, the transformation ability of the two Agrobacterium tumefaciens strains AGL-1 and GV3101 were assessed by utilizing the GUS gene. Both strains were shown to have a high transformation rate of all four sugar beet genotypes tested. Lastly, this thesis also aimed to produce a full-length cDNA clone of BMYV. However, due to difficulties with the amplification of the genome, further work is required to complete the clone. In conclusion, agroinfection can be a valuable tool for resistance screening at DLF Beet Seed, although further work is needed to develop the method.