Pratylenchus (Filipjev, 1936)
The genus name is derived a a contraction of the words pratum (Latin=
meadow), tylos (Greek= knob) and enchos ( Greek=spear).
Originally described as Tylenchus pratensis by De Man in 1880 from
a meadow in England. Pratylenchus scribneri
was reported from potato in Tennessee in 1889.
Root-lesion nematodes of the genus Pratylenchus are recognised worldwide
as major constraints of important economic crops, including banana, cereals,
coffee, corn, legumes, peanut, potato and many fruits. Their economic
importance in agriculture is due to their wide host range and their
distribution in every terrestrial environment on the planet (Castillo and
There are more than 70 described species, fewer than half of them are known to
Morphological identification of Pratylenchus species is difficult, requiring
considerable subjective evaluation of characters and overlapping morphomertrics.
Molecular techniques are increasingly important.
RFLP techniques have been used as a diagnostic method for Pratylenchus
agilis, P. bolivianus, P. brachyurus, P. coffeae, P. crenatus, P. fallax, P.
goodeyi, P. loosi, P. mediterraneus, P. neglectus, P. penetrans, P. pratensis,
P. pseudocoffeae, P. scribneri, P. subranjani, P. thornei, P. vulnus and P.
zeae. The species could be differentiated by a combination of at least two
enzymes. CfoI differentiated all nematode species with the exception of P.
fallax, P. penetrans and P. pseudocoffeae. P. fallax was
separated by a DdeI restriction, and P. pseudocoffeae by a PstI digestion
(Waeyenberge et al, 2000).
Castillo and Vovlas (2007) provide an excellent comprehensive review of
No sexual dimorphism in the anterior part of the body.
Lip area low, flattened anteriorly, not offset, or only weakly
offset, from body contour. SEM reveals that lip area is
characterized by fusion of labial disc with submedial lip sectors;
lateral lip sectors not reduced.
glands overlapping intestine ventrally for a moderate
distance. Esophago-intestinal valve not well developed.
Phasmids located at
mid-tail or slightly posterior.
Female: Genital tract monovarial with posterior branch
reduced to a
Female is slender.
Tail 2 to 3 times the anal body diameter, terminus rounded (rarely
plain, not protruding.
[Ref: Luc, (1987) and H. Ferris.]
Distinguishing the species of Pratylenchus
based on morphometric characters is not easy but may be important as a basis for
management decisions that include resistant varieties, cover crops and crop
Morphometric Key to the Nine Common Pratylenchus Species in
Members of this genus are distributed worldwide; individual species are
influenced by climate.
C- and D-rated pests in California.
No distinct infective stage, adults and juveniles of all stages move in
and out of roots, entering behind zone of elongation but may feed externally at
Feeds on parenchyma cells, largely in cortex, but not exclusively.
Move into root by pushing epidermal cells apart, or moving directly
Inserts stylet into cortical cells and withdraws contents associated
with pulsating of metacorpus.
Access provided for other pathogens by channels left in
Most species have quite wide host ranges.
Sexual reproduction probably occurs in those species where males are
numerous. Fewer than 50% of the described species are recognized asd
having males so parthenogenicity is common in the genus.
Eggs laid singly in roots and soil; second stage hatches from egg.
Nematodes in soil and roots, lesions in roots.
Actual damage caused by nematode feeding is difficult to ascertain because of
associated organisms and secondary infections.
Castillo, P. and Vovlas, N. 2007. Pratylenchus (Nematoda: Pratylenchidae):
diagnosis, biology, pathogenicity and msanagement. Nematology Monographs and
Luc, Rev. Nematol. 10:203-218 (1987)
Waeyenberge, L.; Ryss, A.; Moens, M.; Pinochet, J.; Vrain,
T.C. 2000. Molecular characterisation of 18 Pratylenchus
species using rDNA restriction fragment length polymorphism. Nematology 2: