Nematology (2016) 18, 651-678

Alberto Troccoli, Sergei A. Subbotin, John J. Chitambar, Toon Janssen, Lieven Waeyenberge, Jason D. Stanley, Larry W. Duncan, Paula Agudelo, Gladis E. Múnera Uribe, Javier Franco and Renato N. Inserra (2016)
Characterisation of amphimictic and parthenogenetic populations of Pratylenchus bolivianus Corbett, 1983 (Nematoda: Pratylenchidae) and their phylogenetic relationships with closely related species
Nematology 18 (6), 651-678
Abstract: Amphimictic populations of root-lesion nematodes with numerous males and females having three lip annuli, a functional spermatheca and non-areolated lateral field occur on sword fern (Nephrolepis exaltata) in Florida. Identified for decades as Pratylenchus penetrans, they appeared to be a morphologically separated species on the basis of a longer stylet (17.8-18.3 μm) than P. penetrans (15-17 μm) and different lip pattern in en face view (rectangular vs dumb-bell in P. penetrans). Morphologically similar amphimictic root-lesion nematodes have also been detected on flax lily in Costa Rica. Subsequent morphological observations indicated that these amphimictic root-lesion nematodes from fern and flax lily are closely related to the parthenogenetic species P. bolivianus, which has areolated lateral fields. In spite of the reproductive and morphological dissimilarities between these populations, their separation into different species was not supported by the results of molecular analyses of their DNA sequences. The populations used in these analyses included those that are amphimictic from Florida and Costa Rica and others that are parthenogenetic from the type locality in Bolivia, and geographically distant localities in Chile, China, Colombia and Europe. Phylogenetic analyses of the ITS and D2-D3 expansion segments of the 28S rRNA gene indicated that they belong to the same species, P. bolivianus, which consists of two morphotypes, P. bolivianus (am) amphimictic and P. bolivianus (pm) parthenogenetic, herein described and illustrated. Contradictory results were obtained by the analyses using a portion of the hsp90 gene. The phylogenetic study, which included sequences of other root-lesion nematodes, a topotype and geographical distant populations of P. zeae, revealed that P. bolivianus and P. zeae formed highly supported clades in the majority consensus trees. PCR with species-specific primers for rapid diagnostics of P. bolivianus and P. zeae were developed and tested.
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Link to article at publishers website
Database assignments for author(s): Alberto Troccoli, Lieven Waeyenberge, Larry W. Duncan, Paula Agudelo

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pratylenchus bolivianus		Costa Rica
	Pratylenchus bolivianus		Bolivia
	Pratylenchus bolivianus		Chile (continental)
	Pratylenchus bolivianus		Colombia
	Pratylenchus bolivianus		U.S.A. (SE)