Compendium of Potato Diseases - (PDF, 101 mb) - USAID

many days following removal of the insect front the virus source
petiole-stalklike portion of a leaf attached to the stem and supporting
the lamina
pH-measurement of acidity or basicity. pil7 being neutral, values
below being acid, and those above being basic (alkaline)
phenol (adj. phenolic)-a toxic acidic compound. CHOH, used as a
disinfectant or protein denaturant
phenolase-an enzyme capable of degrading phenolic compounds
phloem-vascular tissue consisting usually of sieve tubes, companion
cells, and parenchyma that conducts elaborated food materials
photochemical oxidants-highly reactive compounds formed byaction
of sunlight on less toxic precursors
photodegredation-degredation due to light, usually sunlight
phyllody-change of a plant organ into a foliage leaf
phytotoxic-harmful to plants; usually describing a chemical
pigmentation-colora tion
pinnate-describing leaves having similar parts arranged on opposite
sides ifthe axis
pitch-in a filamentous virus particle, the axial distance between
adjacent turns of a row of capsids
pith-loose. spongy tissue in the center of certain stems
plasmodium (pl. plasmodia)-naked mass of protoplasm without cell
walls containing nuclei and cytoplasm. usually of itfungus
plastid-any of various cytoplasmic organelles (chloroplasts,
leucoplasts, etc.) that
metabolic
serve in many cases as centers
activities
of special
pleomorphic-with various shapes; of nonnstant form
PlRV-potato lea ri virus
PMV-potato leaf-tolp virus
podzol--ype of light colored, relatively infertile soil of cool, coniferous
forests poor in lime and iron
pollen-male sex cells produced by anthers of flowering plants
polymerize-to subject to or undergo a chemical reaction in
or
which
more similar
two
molecules combine to formlrger molecules of
repeating situctural units
polyploidy-stat of having more than two chromosome sets
polysaccharide-a carbohydrate that can be decomosed by hydrolysis
into two or more molecules of monosaccharides
ppm-parts per million
primary inoculum-inoculum usually from an verwintering source,
that
primry inoului.
initiates
noclumsualy
disease in the
fom
field, rather
n oerwnteingsouce,
disease during
than
the
that
seasonpragtoofoao
which spreads
primary symptom-the symptom produced soon after infection, in
crimasymtom-henda symptom roducd
Contrast
solows
to a secondary
aftrinfectompby
symptom, which follows more complete
prinium (adj. primordial)-stil ridientarv or initiating portion
progmii-dcscpndana'S
front which it plant par'tIrmed . preng hsfo
propagule-an. part of an orgalnism capable of independent growth
protein-anyacidr
prot1inanf no o'l nncrousare
whi naturaly tessentiacuirrituencomplexllolbinationl
occurring, complex combinations
o aiiino acids. -hich areessential constituents ofall living cells
protox rn athe first-I ornugd x veni. with anntlar. spira. or
pseudosclerotia-sclcroliaik structures
I'SlV-postato spidlc iiiher iroid
psdid-ip planl w c he hily Iylasomatic-relating
ps) Ilids -0iuping planti lice of i he fami ly Ps vI (lidae
punctate-dotlike. iiarked vith dots or tiny spots
pustule-blisterlikc: small crumpent spot. spore mass, or sorus
IVA-potuto \irus A
IVM-potato irus M
PVS-potato virus S
'1VT-potato virus I
PVX -potato virus X
l'V-potato virus Y
pycnidiospores-sporcs (conidia) produced in i pycnidium
pycnidium (pl. picnidia)-asexual. globose or flask-shaped fruiting
body of fungi producing conidia
IVV-pota IIYD')V--potato t yell yellow ow dwarl vfi irus virus
IN~V-potato vellosv vein viruseniom
quinones-any of various (usually yellow, orange, or red) quinonoid
compounds, including several that are biologically important as
coenzymes. hydrogen acceptors, or vitamins
race-biotype
reducing sugars-sugars with free carbonyl groups such as fructose,
formed from hydrolysis of complex sugars
resistance (adj. resistant)-property of hosts that prevents or impedes
infection or disease development
120
resorption-the action of absorbing again a substance previously
differentiated
respiration-enzymatic reactions within a living organism utilizing O2
and releasing CO., usually for production of energy
resting spore-temporarily dormant spore, asually thick-walled, and
capable of surviving adverse environments
reticulum (adj. reticular, reticulate)-netlike or weblike structure
rh-relative humidity
rhizome-horizontal underground stem of more than one year's
growth, possessing buds, nodes, and usually scalelike leaves
rhizomorph-fungus mycelium arranged in strands, rootlike in
appearance
rhizosphere-microenvironnient in soil near to and influenced by plant
roots
ribonucleic acid-any of a number of nucleic acids containing ribose,
uracil, guanine, cvtosine, and adenine and associated with control of
cellular chemical activity; the nucleic acid type of most plant viruses
RNA-ribonucleic acid
rogue (noun)-diseased or abnorm;,l plant; (verb)-to remove rogues
during their growth
root cap-protective cap covering apical meristem at root tip
rosario-arranged as heads on a string (Spanish for rosary)
rugose mosaic-severe mosaic accompanied by deformation such as
leaf crinkling, curling, or roughening of leaf surface
saprophyte--nonpathogenic plant that obtains nourishment from the
products of organic breakdown and decay
scald-a necrotic conditiin of tissue, usually bleached in color, with
appearance of having been exposed to high temperature
sclerotia-drought-resistant or heat-resistant form of fungus structure,
usually with thick, hard cell walls permitting survival over adverse
environments
second growth-resumption of growth after normal growth has ceased
secondary organism-organism that multiplies in already diseased
tissue; aot the primary pathogen
secondary rot-rot caused by Isecondary organism
secondary symptom-symptom of virus infection appearing after first
(primary) symptoms; in potato, a symptom often from infection
borne by seed-tubers
seed tubers-tubers or tuber parts planted as seed for asexual
propagation of potato
senesce (n. senescence)-to decline with maturity orage; often hastened
stress from environment or disease
septum (pl. septa)-cross wall
serological method-several types of tests for identifying viruses by
using an antiserum that reacts specifically with a given virus protein
serum-colorless, liquid component of blood used in serological tests
for viruses
seta (pl. setae)-bristelike fungus structure
sieve tube-a tube consisting ofan end-to-end series of thin-walled cells
in the phloem, with ends (sieve plates) perforated and thickened,
functioning chiefly in translocation of organic solutes
solanine-a potentially toxic glycoalkaloid present in plants of the
Solanaceae, including potato
to the body, especially body cells as distinguished
from germ plasm
som aerraim
somatic aberration-mutation orabnormality ina somatic celland its
progeny
sorus (pl. sori)-a group of spores that is formed within plant tissue and
that may erupt through the surface
sp. (singular, pl. spp.)-species
specific gravity-in potatoes, dry matter content of tubers expressed as
weight per unit of volume; used as an indication of starch content
sporangium (pl. sporangia)-a type of fungus structure producing
asexual spores, usually zoospores
sporangiophore-a sporangium-hearing body of a fungus
spore-reproductive one or more cells; body a bacterial of fungi and cell other
modified
lower
to
plants,
survive
containing
adverse,.
environment
sporiferous-bea ring or producing spores
sporophore-a spore-bearing body in fungi
sporulating-producing and often liberating spores
ssp.-subspecies
sterigma (pl. sterigmata)-small, usually pointed protuberance on
which basidiospores are borne
sterile-free from contaminant organisms; incapable of propagation;
infertile
stolon-type of underground stem on the tip ofwhich. in potato, tubers
are formed
stomate (pl. stomata)-opening in the epidermis of a plant part