Biology Reference
In-Depth Information
Chemotherapy
. Treatment of internal disease by
chemical agents that have a toxic effect on the
microorganism without injuring the plant.
Chlamydospore
. Thick-walled, asexual resting
spore formed by the rounding up of any myce-
lial cell (Fig. 2, p. 300); also used for smut
spores.
Chlorosis
. Yellowing of normally green tissue
due to partial failure of chlorophyll to
develop; often due to unavailability of iron
(Fig. 4, p. 277).
Cilium
, pl.
Cilia
. Hairlike swimming organ on
bacteria or zoospores.
Cirrhus
, pl.
Cirrhi
. A tendril or horn of forced-out
spores.
Clamp
-
connections
. Outgrowths
Decumbent
. Resting on substratum with ends
turned up.
Decurrent
. Running down the stipe or stem.
Diagnosis
. Identification of nature and cause of
a disease.
Dieback
. Progressive death of branches or shoots
beginning at tips.
Defoliate
. To strip or become stripped of leaves.
Dichotomous
. Branching, frequently successive,
into two more or less equal arms.
Dimidiate
. Having one half smaller than the
other; of a perithecium, having outer wall
covering only top half.
Discomycetes
. The cup fungi, a subclass of
Ascomycetes; with apothecia.
Disease
. A condition in which use or structure
of any part of the living organism is not
normal.
Disinfection
. Freeing a diseased plant, organ, or
tissue from infection.
Disinfestation
. Killing or inactivating disease
organisms before they can cause infection;
on surface of seed or plant part, or in soil.
Dissemination
. Transport of
of
hyphae
which form bridges
around septa,
thus
connecting two cells;
in Basidiomycetes
(Fig. 4, p. 41).
Clavate
. Club-shaped.
Cleistothecium
, pl.
Cleistothecia
. A perithecium
without
a
special opening;
in powdery
mildews (Fig. 2, p. 286).
Coalesce
. Growing together into one body or
spot.
Coenocytic
. Multinucleate; mycelia having no
cell walls.
Columella
. Sterile central axis in a mature
fruiting body (Fig. 2, p. 36).
Concentric
. One circle within another with
a common center.
Conidiophore
. Simple or branched hyphae on
which conidia are produced.
Conidium
, pl.
Conidia
. Any asexual spore except
sporangiospore or chlamydospore.
Conk
. Term used in forestry for sporophores of
Polyporaceae on trees.
Control
. Prevention of, or reduction of loss from,
plant disease.
Coremium
, pl.
Coremia
. Synnema, a cluster of
erect hyphae bearing conidia (Fig. 5, p. 43).
Coriaceous
. Like leather in texture.
Culturing
. Artificial propagation of organisms on
nutrient media or living plants.
Cystidium
, pl. Cystidia. Sterile, often swollen cell
projecting from hymenium in Basidiomycetes.
Damping
-
off
. Seed decay in soil, or seedling
blight.
inoculum from
a diseased to a healthy plant.
Disjunctor
. Cell or projection connecting spores
of a chain.
Duster
. Apparatus for applying fungicides in dry
form.
Echinulate
. Having small, pointed spines; used of
spores.
Endoconidium
, pl.
Endoconidia
. Conidium
formed within a hypha.
Enphytotic
. A plant disease causing constant
damage from year to year.
Epiphytotic
. Sudden and destructive develop-
ment of a plant disease over an extensive
area, an epidemic.
Eradicant Fungicide
. One that destroys a fungus
at its source.
Eradication
. Control of disease by eliminating
the pathogen after it is already established.
Erumpent
. Breaking
through
surface
of
substratum.
Excentric
. Off center.
Exclusion
. Control of disease by preventing its
introduction into disease-free areas.
Exudate
. Liquid discharge from diseased tissues.
