Question

Using examples to illustrate your answer, describe the role(s) of mycoparasitic fungi in the protection of plants and their potential relevance in biocontrol applications

Answer 1

• FUNGI AS BIOCONTROL AGENT
• TRICHODERMA SPECIES;[Telomorph hypocrea} these are most successful boifungicides used in today's agriculture.
• It colonize plant roots both externally and internally.
• Trichoderma derive sucrose and other materials from plants,in return for boosting plant immunity against invading pathogens and improving photosynthetic ability.
• AS BIOHERBICIDE;;
• A fungus Phytophthora palmivora does not allow milkweed vine to grow in citrus orchards.
• fungal spores are now available to be sprayed over weeds for their elimination. Two of them are DEVINE and COLLEGO. The spores are ideal for marketing because they can tolerate adverse conditions and can remain viable for long periods.
• FUNGI AS BIOINSECTICIDES;;
• it is the control of plant pest through the search of their natural parasites and pathogens. e.g
• A fungus named Entomophthora ignobilis helps in controlling peach aphid of potato [Myzus persicae]
• In U.S.S.R the fungus Beauveria bassiana has been successfully employed in controlling potato beetle codling moth.
• FUNGUS AS BIOFERTILIZER ;;
• MYCORRHIZA;; it is the mutually beneficial or symbiotic associaton of a fungus with the roots of higher plants.Depending upon the residence of fungus mycorrhiza are of two types.

1. ECTOMYCORRHIZA ;; Fungus forms a mantle on the surface of the roots.

• Fungus takes sugar and other food from plants and in turn perform several functions for plants like absorption of water and nutrients from soil for the plants.Fungus also secrete antimicrobial substances to protect the root from attack of pathogen.
• plants such as Eucalyptus ,peach ,pine.
• fungus usually belong to basidiomycetes.
• 2}ENDOMYCORRHIZA;; Fungus penetrate deep inside the cortex of the root,even the cortical cells.
• The hyphal tips passing into the cortical cells either produce swollen vesicles or finely branched masses called arbuscules. Therfore it is called VAM{vesicular arbuscular mycorrhiza}
• VAM supply inorganic nutrientsand also enhance water absorption. It makes the phosphate available to the plants.
• A single fungus may form mycorrhizal associations with a number of plants,e.g GLOMUS.