Turnip yellows virus (TuYV) TuYV is spread by greenfly (aphids) and can cause major losses of yield in Brassica crops (e.g. oilseed rape, Brussels sprouts, broccoli etc.). Symptoms can include yellowing, or purpling of the leaves and stunIng of plants; environmental stresses can cause similar symptoms, making it hard to idenIfy virus-­‐infected plants by eye. TuYV is known to reduce the yield of oilseed rape by at least 30% in some regions of the UK, making it one of the major causes of yield loss. TuYV is not well researched, resulIng in limited geneIc informaIon. No whole genomes of European isolates of the virus have been sequenced. Our group is addressing this shortage of informaIon by sampling and tesIng oilseed rape crops around the UK and Europe and building a database of TuYV isolates found. Our research focuses on understanding the gene=c and geographic diversity of the virus and exploiIng sources of natural plant resistance to the virus. We are working with oilseed rape breeders to exploit our sources of resistance to TuYV in order to increase yields and reduce the need for insec=cides that are sprayed on crops, in a]empts to control the insect vectors of the virus. Aphids Turnip yellows virus parIcles (electron micrograph, Colin Clay). TuYV-­‐ infected Aphids on a brassica plant. Healthy Yield reducIon in Brussels sprouts caused by Turnip yellows virus. An aphid as seen in a scanning electron microscope (electron micrograph, Colin Clay). School of Life Sciences, Wellesbourne Campus, University of Warwick, CV35 9EF. Turnip mosaic virus (TuMV) Clubroot (Plasmodiophora brassicae) TuMV is the second most important virus affecIng field-­‐grown vegetables world-­‐wide, e.g. cabbage and other Brassica species. The Turnip mosaic virus NecroIc spots on Cabbage parIcles (electron due to TuMV infecIon. virus causes significant economic losses in micrograph, Colin Clay). these crops. TuMV is spread by greenfly (aphids). Virus symptoms, including black spots on the plants, make infected plants undesirable and unmarketable. Our group works on discovering the geneIc basis of natural Healthy TuMV-­‐infected resistance to TuMV and the deployment of this Turnip mosaic virus symptoms. in commercial crops. In collaboraIon with Syngenta Seeds, following our discovery of the genes controlling TuMV resistance, virus-­‐
resistant Chinese cabbage seed will soon be available for growers. We are now focusing on idenIfying genes controlling other sources of resistance to TuMV for other brassica crops. Brassica field devastated by Turnip mosaic virus Clubroot is a parasiIc organism which infects the roots of brassica crops, such as broccoli, cabbage, sprouts and oilseed rape (Brassica species). It can severely reduce yields, or even cause total crop loss in some fields. It is a resilient organism and tradiIonal sterilisaIon techniques have oQen failed to kill the clubroot spores. A current group project is invesIgaIng heat treatments and disinfectants for their efficacy in killing clubroot spores. A range of op=ons will then be made available to growers for sterilising infected equipment. The research is at an early stage but preliminary results look promising. (InsItute of Vegetables and Flowers, Beijing). 0 1 2 3 Broccoli plant infected with clubroot. Varying severiIes of clubroot following infecIon with different quanIIes of spores; 0, healthy – 3, severely infected. Contact: john.walsh@warwick.ac.uk