Pratylenchus scribneri Steiner, 1943
Scribner's Root Lesion Nematode
Strong head frame, flattened lip region.
Ventral overlap of esophageal
glands over intestine.
Monovarial, prodelphic; short
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Africa: Cameroon, Asia: China, Pakistan, Turkey, Europe: Italy, North
America: United States (widespread in 35 states) Readily distributed in
tooted plant material (Scheck, 2022).
in California Nematode Pest Rating System.
Migratory endoparasite of
Males not present, not sexually reproducing. Roman and Triantaphyllou
(1969) determined that there are two reproductive forms in the species; one has
n=6 chromosomes and reproduces by meiotic parthenogenesis, the other has a
somatic chromosome number of about 25 and reproduces by mitotic parthenogenesis.
In meiotic parthenogenesis there is no fertilization of oocytes
and a meiotic reduction division of the unfertilized egg cell; the diploid
number of chromosomes is re-established by fusion with the nucleus of a
In mitotic parthenogenesis there is no fertilization and there is mitotic
division of oogonia so that the somatic number of chromosomes is preserved
Infected roots have initial symptoms of small, water-soaked lesions
that soon turn brown to black. Black lesions are formed along the root axis and
may coalesce laterally to girdle the roots. Infected plants have fewer feeder
roots, resulting in stunted root growth. Top growth may exhibit general symptoms
of an impaired root system including lack of vigor, dieback, chlorotic and small
leaves, and reduction of yield.
In general, root lesion infection results in plants exhibiting symptoms
of chlorosis, wilting, and stunting.Affected root tissue may slough off
leaving a severely reduced root system. Secondary infection by fungi and
bacteria may further destroy the root system by causing sloughing off of the
root tissues and rot (Chitambar et al, 2018, Scheck, 2022).
Pratylenchus scribneri is an economic pathogen causing damage to the
roots and loss of yield to a wide range of crops, including barley, maize,
soybean, potato, sugar beet, broccoli, tomato, onion, strawberry, and peach
(Castillo and Volvas 2007). It reduces the yield and quality of potato
tubers (Orlando et al., 2020).
Host Plant Resistance, Non-hosts
Acosta, N. and R. B. Malek (1981). Symptomatology and histopathology of
soybean roots infected by Pratylenchus scribneri and P. alleni. J.
Castillo, P., and Volvas, N. 2007. Pratylenchus (Nematoda:
Pratylenchidae): Diagnosis, Biology, Pathogenicity and Management.
Nematology Monographs and Perspectives, Vol. 6. Brill, Leiden, The
Chitambar, J. J., Westerdahl, B. B., and Subbotin, S. A. 2018. Plant
Parasitic Nematodes in California Agriculture. In Subbotin, S., Chitambar
J., (eds) Plant Parasitic Nematodes in Sustainable Agriculture of North
America. Sustainability in Plant and Crop Protection. Springer, Cham.
Orlando, V., Grove, I.G., Edwards, S.G., Prior, T., Roberts, D., Neilson,
R. and Back, M., 2020. Root‐lesion nematodes of potato: current status of
diagnostics, pathogenicity and management. Plant Pathology, 69(3),
Roman, J., Triantaphyllou, A.C. 1969. Gametogenesis oand reproduction of
seven species of Pratylenchus. J. Nematology 1:357-362.
Scheck, H.J. 2022. California Pest Rating Proposal for Pratylenchus
scribneri Steiner, 1943 Scribnerï¿½s root-lesion nematode CDFA, Sanramento,
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