 |
| Home | |
| Diseases | |
| Photo Gallery | |
| Glossary | |
| Reference Material | |
| Site Map |
 |
|
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
A
Aeciospore - a spore produced in the aecidium Aecidium - in rust fungi a cup-shaped structure containing chains of spores Alternate host - a second host (of a different plant species) required by some pathogens in order to complete their life cycle Anamorph - the imperfect or asexual stage of a fungus Apothecium - a cup- or saucer-like ascocarp Asexual - without sex organs or sex spores: vegetative Ascocarp - a fruiting body which bears asci Ascospores - sexually produced spores contained within an ascus Ascus (pl. asci) - a sac-like cell which contains the products of the sexual stage (teleomorph) as B Basidiocarp - a fruiting body which bears basidia Basidiospores - (sexually produced) spores borne on the outside of a basidium Basidium - a cell or organ from which the sexually produced basidiospores (generally 4) are formed Biotroph - an organism entirely dependent upon another living organism (the host) as a source of nutrients Boot - characteristic swelling in the stem of a cereal plant, produced as the developing ear moves up the stem Break crop - a crop (e.g. oilseed rape) grown in rotation with other crops (e.g. wheat) to improve the growing conditions of the following crop C Chlamydospore - an asexual spore arising from a hyphal segment, a resting stage Chlorosis - the yellowing of normally green plant tissue Cleistothecia - the closed spherical ascocarp of the powdery mildews Coalesce - to unite or come together in one body or mass Coleoptile - protective sheath surrounding the emerging shoot of a cereal Conidia - asexual fungal spores formed from the end of a conidiophore Conidiophore - a specialised hypha on which one or more conidia are produced Cortex - the layer of cells between the epidermis and the vascular bundles Cotyledon - part of the embryo that forms the primary leaf Crown roots - the roots which emerge from the base of the stem of the plant rather than the seed D Damping-off - disease of plant seedlings caused by seed- or soil-borne fungi Dicotyledon - a flowering plant whose embryo has two cotyledons (seed leaves) Dieback - necrosis of a shoot beginning at the apex and spreading towards the older tissue, stem death may occur Direct drilling - the drilling of seed into ground which has received minimal cultivation E Ear blight - infection of cereal ears resulting in bleaching of parts of the ear or discolouration of the glumes and grains Ear primordial - original formation of the ear Endosperm - nutritive tissue in a seed Epidemic - a widespread increase in the incidence of an infectious disease Epidermis - the outermost layer of cells of an organ, usually only one cell thick Ergot - the fruiting structure (sclerotium) of Claviceps spp. F Flag leaf - the final leaf to emerge in a cereal plant Focus (pl. foci) - a site of local concentration of diseased plants, usually about a primary source of infection or coinciding with an area originally favourable to disease establishment Forma specialis (f. sp) - a group within a pathogen species that can only infect particular hosts G Glume - an outer and lowermost bract of a grass (including cereals) spikelet (inflorescence) H Honeydew (fungal) - a sticky secretion containing conidia produced during the lifecycle of Claviceps purpurea (Ergot) Host - a living organism harbouring a pathogen Host specific - pertaining to a particular host, generally species specific Hybrid - cross between two varieties or species of plant or animal Hypha - one of the filaments of a mycelium I - K Immune - cannot be infected by a given pathogen L Leaf sheath - the lower part of the leaf which surrounds the stem more or less completely Lesion - a localised area of diseased tissue Lodging - when a standing crop is caused to lean or bend due to adverse weather or soil conditions M Minimal cultivation - a reduced form of cultivation N-O Necrotroph - micro-organism feeding only on dead organic tissue Node - the level of a stem at which one or more leaves arise Ovary - the core of the carpel of a flower, in which seeds are produced P-Q Pathogen - an organism which causes disease Perithecium - an ascocarp shaped like a flask containing asci Primary inoculum - spores or fragments of mycelium capable of initiating disease Pseudothecia - a peritheca-like structure with a single cavity containing ascospores Pustule - a spore mass developing below the epidermis and then breaking through at maturity Pycnidium - flask shaped fruiting body with an apical pore lined internally with pycnidiospores Pycnidiospores - spores from within a pycnidium R Rachis - the main axis of the inflorescence, or spike, of wheat and other cereals, to which the spikelets are attached Resistance - the inherent capacity of a host plant to prevent or reduce the development of a disease S Saprophyte - an organism deriving its nutrients from dead or decaying tissue of another organism Sclerotia - compact mass of fungal hyphae e.g. ergot, capable of being dormant for long periods, and giving rise to fruiting bodies or mycellium Seminal roots - the roots developing directly from the seed Senescence - the dying process of a plant or plant part Sporangiophore - a hypha or fruiting structure bearing spores Sporangium - a container or case of asexual spores. In some cases it functions as a single spore Spore - a reproductive unit in fungi Sporulation - the period of active spore production Susceptible - non-immune i.e. capable of becoming infected by a Pathogen T Telium - structure containing teliospores Teliospores - sexual spores produced within a telium Teleomorph - the sexual or so-called perfect growth stage or phase in fungi Tolerance - the ability of a plant host to sustain the effects of a disease without dying or suffering serious injury or crop loss Toxic alkaloids - harmful substance found in plants which use them as defence against herbivores U Uredium - the fruiting structure of a rust fungi in which uredospores are produced Uredospore - the asexual spore of the rust fungus V Vascular tissue - in plants, xylem and phloem. Vector - an organism capable of transmitting inoculum Virulence - the ability of a pathogen to produce disease W-Z White-head - prematurely ripened ears of cereals often caused by pathogens attacking the roots or stem base Xylem - tissue within plants which conducts water and mineral salts, absorbed by roots from the soil, throughout the plant |
| www.hgca.com |
