Glossary of phytopathology

This is a glossary of some of the terms used in phytopathology.

Phytopathology is the study of plant diseases. It is a multi-disciplinary since prerequisites for disease development are the presence of a susceptible host species, a pathogen and the appropriate environmental conditions. This is known as the disease triangle. Because of this interaction, the terminology used in phytopathology often comes from other disciplines including those dealing with the host species ( botany / plant science, plant physiology), the pathogen ( bacteriology, mycology, nematology, virology), the environment and disease management practices (agronomy, soil science, meteorology, environmental science, ecology, plant breeding, pesticides, entomology), and areas of study that apply to both the host and pathogen (molecular biology, genetics, molecular genetics). The result is that most phytopathological glossary include terms from these other disciplines in addition to terms (disease incidence, horizontal resistance, gene-for-gene relationship, blast, scab and so on) that are specific to, or which have a unique meaning in phytopathology. This glossary is no exception. However, for the sake of brevity, it has for the most part, restricted terms from other disciplines to those that pertain to the pathogen. At some point, these terms should be moved to other glossaries (e.g. glossary of mycology, glossary of nematology, and so on).

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A

;abiotic

;acceptable daily intake

;acervulus (pl. acervuli):The acervulus is an erumpent, cushionlike fruiting body bearing conidiophores, conidia, and sometimes setae. It is distinguished from a stroma in not having a peridium or covering of fungal tissue of any kind.

;acid precipitation

;acid rain

;acropetal

;Actinomycetes:The Actinobacteria or Actinomycetes are a group of Gram-positive bacteria.

;acute

;acute toxicity

;aeciospore

;aecium

;aflatoxin

;agar

;aggressiveness

;air pollution

;alkaloids

;allele

;allelopathy

;alternate host

;alternative hosts

;alternation of generations

;amphid

;amphigynous

;amphimixis

;amphimobile

;anaerobic

;anamorph (adj. anamorphic; syn. imperfect state)

;anastomosis (pl. anastomoses)

;anthracnoes

;antibiotic

;antibody

;antigen

;antiseptic

;apothecium:The apothecium is an open, cuplike, or saucer-shaped sexual fungal fruiting body (ascocarp) containing asci.

;antiseptic

;appressorium (pl. appressoria)

;arbuscular mycorrhiza (abbr. AM; syn. endomycorrhiza)

;arbuscule

;ascocarp (syn. ascoma)

;ascogenous

;ascogonium (pl. ascogonia)

;ascoma (pl. ascomata; syn. ascocarp)

;Ascomycetes

;asci

;ascospore

;ascostroma (pl. ascostromata)

;ascus (pl. asci)

;aseptate

;asexual

;asexual reproduction

;atrophy

;AUDPC (abbr. for Area Under Disease Progress Curve)

;autotroph

;avirulence (avr) gene

;avirulent (syn. nonpathogenic)

;axenic

;autoecious

B

;bacilliform

;bacterial streaming

;bactericide

;bacteriocin

;bacteriophage

;bacterium (pl. bacteria)

;bactericide

;basal knob (syn. stylet knob)

;basidiocarp (syn. basidioma)

;Basidiomyctes:The Division Basidiomycota is a large taxon within the Kingdom Fungi that includes those species that produce spores in a club-shaped structure called a basidium.

;basidiospore

;basidium (pl. basidia)

;basidiospore

;basidium (pl. basidia; adj. basidial)

;binary fission

;binucleate

;bioassay

;biocide

;biocontrol (syn. biological control)

;biotic

;biotroph (syn. obligate parasite)

;biotype

;bitunicate

;blasting

;blight

;blotch

;breaking

;broadcast application

;brooming

;brown rot (of wood)

;

;burn

;bursa

C

;canker

;capsid (syn. coat protein)

;carcinogen

;carrier

;casting

;causal agent

;certification

;cfu (abbr. for colony forming unit)

;chemotaxis (syn. chemotropism)

;chemotherapy

;chlamydospore

;chlamydospore:A chlamydospore is the thick-walled big resting spore of several kinds of fungi.

;chlorosis

;chronic toxicity

;chytridiomycetes

;circulative-propagative transmission (syn. propagative transmission)

;circulative transmission (syn. persistent transmission)

;cirrus

;cleistothecium

;clamp connection

;clavate (or claviform)

;coalesce

;coat protein (syn. capsid)

;coccus (pl. cocci)

;coelomycetes

;colonization

;colony

;colony forming unit (abbr. cfu)

;compartmentalization

;conidiogenesis

;conidiogenous

;conidioma (pl. conidiomata)

;conidiophore

;conidium (pl. conidia)

;conjugation

;conk

;constitutive

;contact fungicide (syn. protectant fungicide)

;coremium (pl. coremia; syn. synnema)

;cross-protection

;crozier

;cryptobiosis (hidden life)

;curl

;cyst

;cytopathology

D

;damping-off

;days to harvest

;decay

;degree-day

;demicyclic

;deuteromycetes (syn. Fungi Imperfecti)

;diagnostic

;antigen

;diploid:Diploid (2x) cells have two copies (homologs) of each chromosome, usually one from the mother and one from the father.

;diapause

;dieback (v. die back)

;differential host (syn. differential cultivar)

;differential medium

;differentiation

;dikaryon (adj. dikaryotic)

;dilution plating

;dilution streaking

;dimorphic

;direct penetration

;Discomycetes

;disease

;disease cycle

;disease incidence

;disease progress curve

;disease pyramid

;disease severity

;disease triangle

;disinfect

;disinfest

;dispersal (syn. dissemination)

;dissemination (syn. dispersal)

;dolipore septum

;dormancy (adj. dormant)

;downy mildew

;drift (of pesticides)

;drought

;durable resistance

;dwarfing

E

;echinulate

;economic threshold

;ectomycorrhiza (pl. ectomycorrhizae)

;ectoparasite

;ectotrophic

;elicitor

;enation

;encapsidate

;encyst

;endemic

;endogenous

;endophytic

;endoconidium (pl. endoconidia)

;endomycorrhiza (pl. endomycorrhizae; syn. arbuscular mycorrhiza)

;endoparasite

;endospore

;epidemic

;epidemiology

;epinasty

;epiphytotic: The epidemic condition of a disease, in a plant population. Compare with enphytotic

;eradicant

;eradication

;ergot

;ergotism

;erumpent

;escape

;etiolation

;etiology

;exclusion

;exogenous

;exudate

F

;f. sp. (abbr. for forma specialis)

;facultative parasite

;facultative saprotroph

;fasciation

;fastidious

;filamentous (syn. filiform)

;flagellum

;flagging

;fleck

;focus (pl. foci)

;forest decline

;forma specialis (abbr. f.sp.; pl. formae speciales)

;fructification

;fruiting body

;fumigant (v. fumigate)

;Fungi Imperfecti (syn. Deuteromycetes

;fungicide (adj. fungicidal):Chemical designed to kill fungi

;fungus (pl. fungi)

;fungistat (adj. fungistatic):Inhibits growth of some fungi.

;fungistasis

;fusiform

G

;gall

;gametangium (pl. gametangia)

;gametophyte

;gene-for-gene hypothesis

;general resistance (syn. horizontal resistance, race non-specific resistance)

;genotype

;germ theory

;giant cell

;girdle

;giant cells

;gram-negative:Gram-negative bacteria are those that do not retain crystal violet dye in the Gram staining protocol.

;gram-positive:Gram-positive bacteria are classified as bacteria that retain a crystal violet dye during the Gram stain process.

;gram stain

;growth regulator (syn. hormone)

;gummosis (pl. gummoses)

H

;haploid

;hardiness

;haustorium (pl. haustoria): The haustorium is the hyphal tip of a parasitic fungus

;hemiparasite

;hermaphrodite (adj. hermaphroditic)

;heteroecious

;heterokaryon (adj. heterokaryotic)

;heterothallic

;heterotroph

;holomorph

;holoparasite

;homokaryon (adj. homokaryotic)

;homothallism (adj. homothallic)

;horizontal resistance (syn. general resistance, race non-specific resistance)

;host plant

;host range

;hyaline

;hymenium

;hyperparasite

;hyperplasia

;hypertrophy

;hypersensitive

;hypersensitive reaction and pathogenicity (hrp) gene

;hypersensitive response (HR)

;hypha

;hyphal sheath (syn. mantle)

;hyphomycetes

;hyphopodium

;hypoplasia

;hypovirulence

I

;immune;immunity;imperfect fungi (syn. Fungi Imperfecti, deuteromycetes);imperfect state (syn. anamorph);in planta;in situ;in vitro;in vivo;incubation period;indicator plant;indirect penetration;induced;induced systemic resistance (ISR);infection court;infection cushion;infection focus;infection peg (syn. penetration peg) ;infection period;infectious;infective;infest (n. infestation) ;initial inoculum (syn. primary inoculum);injury;inoculate (n. inoculation);inoculum (pl. inocula);inoculum density;integrated pest management (abbr. IPM);intumescence (syn. edema or oedema) ;IPM (abbr. for integrated pest management) ;isolate

K

;klendusityThe disease-escaping ability of plants.;Koch's postulates;knot

L

;latent infection;latent period;leaf dip;leaf spot;leafroll;lesion;life cycle;lignification;local lesion;local necrosis;lodge

M

;macerate;macroconidium (pl. macroconidia) ;macrocyclic;macronutrient;mantle (syn. hyphal sheath) ;mating types;mechanical injury;mechanical transmission;medium (pl. media) ;melanin;microbial;microclimate;microconidium (pl. microconidia) ;microcyclic;microflora;micronutrient;microorganism (syn. microbe);microsclerotium ;mildew;MLO (syn. mycoplasmalike organsim) ;mold;mollicute;monocyclic;monoecious;monogenic;monogenic resistance (syn. single gene resistance);monotrichous;monoxenic culture;mosaic;motile;mottle;movement protein;multigenic resistance (syn. polygenic resistance);multiline;multinucleate;multiparticulate virus;multipartite virus;multiseptate;mummification;mummy;mushroom;mutagen;Mycelia sterilia;mycelium (pl. mycelia):Mycelium is the vegetative part of a fungus consisting of a mass of branching, threadlike hyphae that exists below the ground or within another substrate.;mycology;mycoparasite;mycoplasmalike organism (syn. MLO) ;mycorrhiza (pl. mycorrhizae; adj. mycorrhizal) ;mycotoxin;mycovirus;Myxomycetes (syn. slime molds)

N

;necrosis (adj. necrotic) ;necrotroph;needle cast (of conifers) ;nematicide:A nematicide is a type of chemical pesticide used to kill parasitic nematodes.;nematode:Nematodes are unsegmented, bilaterally symmetric and triploblastic protostomes with a complete digestive system.;nitrogen oxides;noninfectious disease;nonpathogenic (syn. avirulent) ;nonpersistent transmission (syn. stylet-borne transmission);nonseptate

O

;obligate parasite (syn. biotroph);occlusion;oedema (also edema; syn. intumescence) ;oligogenic resistance;oogonium (pl. oogonia):An oogonium is a female gametogonium.;oomycetes (adj. oomycetous);oospore;ooze;ostiole (adj. ostiolate);overwinter

P

;pandemic;papilla;paragynous ;parasexualism;parasite (adj. parasitic);parasitism;parthenogenesis (adj. parthenogenetic);partial resistance;pasteurization;pathogen (adj. pathogenic) ;pathogenesis-related (PR) proteins;pathogenicity;pathology;pathotype;pathovar (abbr. pv.) ;penetration;penetration peg (syn. infection peg) ;perfect (see teleomorph);perithecium (pl. perithecia);peritrichate;persistent transmission (syn. circulative transmission) ;pest;pesticide;phenological synchrony;phenotype;phloem necrosis;Phycomycete;phyllody;phylloplane-competent;physiogenic disease;phytoalexin;phytopathogenic;phytopathology (syn. plant pathology) ;phytoplasma (syn. mycoplasmalike organism, MLO) ;phytosanitary certificate;phytotoxic;plant pathology (syn. phytopathology) ;plasmodiophoromycetes;plasmodium (pl. plasmodia) ;polycyclic;polyetic;polygenic resistance (syn. multigenic resistance);polymorphism;polyprotein;powdery mildew;predispose (n. predisposition)

;primary inoculum (syn. initial inoculum) ;proinhibitin;prokaryote;promycelium (pl. promycelia) ;propagative transmission (syn. circulative propagative transmission) ;propagule;protectant;protectant fungicide (syn. contact fungicide);pseudothecium (pl. pseudothecia);Puccinia pathway;pustule;pv. (abbr. for pathovar);pycnidiospore;pycnium (pl. pycnia; syn. spermagonium) ;;

Q

;qualitative resistance;quantitative resistance;quarantine;quiescent;quiescent;dormant or inactive;quorum sensing

R

;race;race non-specific resistance (syn. general resistance, horizontal resistance);receptive hypha;reniform;resinosis;resistant (n. resistance) ;rhizomorph;rhizosphere;rhizosphere-competent;ringspot;rosette;rot;roundworm;rugose;russet;rust

S

;sanitation;sap transmission;saprobe (syn. saprotroph);saprotroph:A saprotroph (or saprobe) is an organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or animal matter, by absorbing soluble organic compounds.;scab;scald;sclerenchyma (adj. sclerenchymatous);sclerotium (pl. sclerotia) :A sclerotium is a compact mass of hardened mycelium (as an ergot) stored with reserve food material that in some higher fungi becomes detached and remains dormant until a favorable opportunity for growth occurs.;scorch;secondary infection;secondary inoculum;secondary metabolite;secondary organism;seed treatment;seedborne;selective medium ;septate;serrate;sessile;seta (pl. setae);

;sexual spore;sexually compatible;shot-hole;sign;single gene resistance (syn. monogenic resistance);slime molds (syn. Myxomycetes);smut;soft rot;soil drench;soilborne;soil pasteurization;soil sterilization;solarization;sooty mold;sorus (pl. sori);sp. (abbr. for species; pl. spp.);species;specific resistance (syn. vertical resistance);spermagonium (pl. spermagonia; syn. pycnium for rust fungi) ;spermatium (pl. spermatia; syn. pycniospore for rust fungi);spicule

;spiroplasma - helical, motile, cell wall-less bacterium; member of genus Spiroplasma in class Mollicutes;sporangiophore;sporangiospore;sporangium (pl. sporangia);spore;sporidium (pl.sporidia);sporocarp;spore-bearing fruiting body;sporodochium (pl.sporodochia);sporogenous;sporophore;sporophyte;sporulate;spot;stabilizing selection;staghead;stem pitting;sterigma (pl. sterigmata);sterilant;sterile fungus;sterilization (adj. sterilized);stippling;strain

;streak;striate (n. striations);stroma (pl. stromata);stunting;stylet knob (syn. basal knob);stylet-borne transmission (syn. nonpersistent

transmission);subspecies;substrate;sunscald or sunburn;suppressive soil;susceptible (n. susceptibility);symptom;symptomless carrier;syncytium (pl. syncytia);synergism (adj. synergistic);synnema (pl. synnemata; syn. coremium);systematics;systemic;systemic acquired resistance (SAR) ;systemic fungicide

T

;teleomorph (syn. perfect state);teliospore (sometimes called teleutospore, teleutosporodesm) :Teliospore (sometimes called teleutospore) is the thick-walled resting spore of some fungi (rusts and smuts), from which the basidium arises.;telium (pl. telia);temporary wilt;thallus;thermotherapy;tolerance (adj. tolerant) ;toxicity;toxin;transmit (n. transmission);trap crop;transmit (n. transmission);trenching ;tumor (syn. gall);type

U

;urediniospore (also urediospore, uredospore) ;uredinium (also uredium; pl. uredinia)

V

;vascular wilt disease;vector;vein banding;vein clearing;vermiform;vertical resistance (syn. specific resistance);viable (n. viability);virescence;virion;viroid;viroplasm;virulence;virulent;viruliferous;virus-laden, usually applied to insects or nematodes as vectors;virus:A virus is a microscopic particle (ranging in size from 20 - 300 nm) that can infect the cells of a biological organism.;viscin

W

;walling-off;water-soaked;white rot (of wood);white rust;wild type;wilt;winterburn;witches' broom;wound

X

;XLB (xylem-limited fastidious bacteria);xylem-limited fastidious bacteria (XLB)

Y

;yellowing

;yellows

Z

;zonate;zoosporangium;zoospore:A zoospore is a motile asexual spore utilizing a flagellum for locomotion.;Zygomycetes;zygospore:A zygospore is a sexual part of a fungus, a chlamydospore that is created by the nuclear fusion of haploid hyphae of different mating types.

References

* [http://www.apsnet.org/education/illustratedglossary/ Illustrated Glossary of Plant Pathology, American Phytopathological Society]
* [http://plant-disease.ippc.orst.edu/glossary.cfm Plant Disease Control Glossary, Oregon State University]
* [http://www.ilmyco.gen.chicago.il.us/Terms/TermsFrame.html Mycological Glossary, Illinois Mycological Association]
* [http://www.plantpath.cornell.edu/glossary/Glossary.htm On-Line Glossary of Technical Terms in Plant Pathology, Cornell University] (with pronunciation guide)