Field, glasshouse and laboratory experiments and field surveys were done in Western Australia to develop control strategies for various non-persistently aphid-borne viruses of grain legumes, celery and carrots and for the fungally-transmitted lettuce big vein disease (LBVD). In a range of legumes, extreme resistance to Alfalfa mosaic virus (AMV) was found in Vicia faba cv. Ascot, Hedysarum coronarium cv. Grimaldi, and Lens culinaris IL5480, to Cucumber mosaic virus (CMV) in Lathyrus cicera ATC80521, L. clymenum C7022, Ornithopus sativus cv. Cadiz, and V. sativus cv. Languedoc, and to Pea seedborne mosaic virus (PSbMV) in all accessions and varieties of Cicer arietinum and L. culinaris and some of L. sativus and most pasture legumes tested. No sources of extreme resistance to Carrot virus Y (CarVY) was found to carrot germplasm. The first reports of seed transmission of AMV in Vicia faba and of CMV in Pisum sativum, V. faba, V. narbonensis and eight pasture legumes were made. No evidence for the seed transmission of CarVY was found. Plants of V. faba infected early with AMV recovered while plants infected later incurred yield losses (up to 45%). In contrast, plants of C. arietinum infected with AMV when young were killed. L. culinaris plants infected with AMV and CMV suffered high yield losses (up to 90%) dependent on the age of plants when they were infected. Plants of lettuce infected with LBVD when young often failed to form ‘hearts’ but leaf symptoms were mild, whereas later infected plants had more severe leaf symptoms. Spatial patterns of disease spread were monitored and implications for disease control discussed for CarVY and LBVD. The incidence of CarVY in carrot crops was often high in a wide selection of varieties grown throughout Australia. CarVY was determined to have a wide host range within the Apiaceae family but not in other plant families. No evidence for reservoirs of CarVY was found in species other than carrot, despite extensive surveys of known Apiaceous hosts. CarVY was readily transmitted by a wide range of aphid species in a non-persistent manner. Control strategies for Celery mosaic virus (CeMV), by instigation of a ‘celery free period’ and LBVD by combining resistant lettuce varieties and plastic mulch were demonstrated. New control measures for AMV, CMV, PSbMV and CarVY were also discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:493647 |
| Date | January 2008 |
| Creators | Latham, Lindrea Jane |
| Publisher | University of Greenwich |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://gala.gre.ac.uk/6216/ |
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