Award details

Manipulation of natural enemies of pests in arable crops

Reference	BBS/E/C/00041011
Principal Investigator / Supervisor	Professor Brian Kerry
Co-Investigators / Co-Supervisors
Institution	Rothamsted Research
Department	Rothamsted Research Department
Funding type	Research
Value (£)	339,748
Status	Completed
Type	Institute Project
Start date	01/04/1997
End date	31/03/1999
Duration	24 months

Abstract

This project has been enlarged to bring together basic research on the interactions of microbial pathogens with their invertebrate hosts. The successful exploitation of selected microbial agents is clearly dependent on a thorough knowledge of their biology and ecology. Basic studies on host recognition and infection processes have identified protease enzymes which are virulence and specificity determinants for nematophagous fungi. Such enzymes may provide useful markers to monitor the switch in trophic states of V. chlamydosporium as the fungus changes from a saprophytic to a parasitic mode. The role of the host plant in the growth, physiology and gene regulation of the nematophagous fungus, V. chlamydosporium, in the rhizosphere is being examined using biochemical, immunological and molecular techniques. Similar techniques are used to understand the mechanism of spore attachment of the obligate bacterial parasite, Pasteuria penetrans to nematode cuticle. 2 The entomopathogenic fungus Erynia neoaphidis is an important natural enemy of many pest aphids and has considerable potential for use in biomanagement strategies. Little is known about the toxic metabolites, produced by insect pathogens. The role of Varroa jacobsoni in the epidemiology and induction of latent virus diseases is studied and the interaction of microbes with insect immune systems is a subject of increasing interest. Objectives 1996 (a) To study variation in pathogenicity within isolates of the test fungi. (b) Further studies on Acremonium sp., P. lilacinus and V. chlamydosporium as potential biological control agents of potato cyst nematodes (PCN) and root-knot nematodes (RKN). (c) Study the long term effects of Acremonium sp. and P. lilacinus on populations of PCN and RKN. (d) Continue outdoor pot tests to study the potential of these fungi in the biomanagement of PCN. (e) In collaboration with the Agricultural Research Centre in Sarawak, initiate biomanagement trials against RKN on black pepper in Malaysia. (f) Examine the effects of root exudates on the growth of V. chlamydosporium in the rhizosphere. (g) Continue research on PCR and immunological methods to monitor and quantify V. chlamydosporium in the rhizosphere and soil. (h) Test selected nematophagous fungi for their ability to produce toxins and partially characterise any active compounds. (g) Continue to study the role of fibronectin in the attachment of spores of P. penetrans to nematode cuticle. (i) Cuticle extracts of a range of plant parasitic and free living nematodes such as Caenorhabditis elegans will be analysed for the presence of fibronectin and assessed for their status as hosts for P. penetrans. (j) Extra-cellular enzymes produced by nematode trapping fungi will be tested for their effects on nematode cuticle and the attachment of P. penetrans spores. 1997 1. To evaluate the biomanagement in a second cropping cycle and measure the effects on both nematode and fungal densities. 2. Assess the use of molecular and immunological methods for the detection and quantification of V. chlamydosporium in the rhizosphere. 3. Examine the infection process of Acremonium sp. 4. Assess the pre mortality impacts of entomopathogenic fungi on their insect hosts 5. Examine the impact of abiotic factors, especially rainfall on the efficacy of entomopathogenic fungi 6. Elucidate the importance of enzymes and toxins as host range and virulence determinants for parasitic fungi. 7. Examine further the relationship between the surfaces of mutant C. elegans, parasitic and free-living nematodes and host recognition in nematophagous fungi and bacteria. 8. Examine the effects of Varroa jacobsoni on the foraging behaviour of adult bees. 9. Serological assays will be used to monitor the spread of virus from mites to bees and brood in infested colonies. 10. Monoclonal antibodies will be produced to the slug parasitic nematode Phasmarhabditis hermaphrodita.

Summary

unavailable

Committee	Closed Committee - Agri-food (AF)
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

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