Characterisation of a population of Pratylenchus hippeastri from bromeliads and description of two related new species, P. floridensis n. sp. and P. parafloridensis n. sp., from grasses in Florida

Abstract

Abstract Morphological and molecular analyses confirmed the presence of Pratylenchus hippeastri in regulatory samples collected in commercial bromeliad operations from genera Guzmania, Neoregelia and Vriesea in central and south Florida, USA. Specimens of P. hippeastri from bromeliads contained males which were not detected in the type population from amaryllis and are described herein for the first time. The rDNA sequences of these males matched those of P. hippeastri female type material. Pratylenchus hippeastri and root-lesion nematodes from several hosts in Florida were characterised at the morphological and molecular level, whereas other samples from Russia and South Africa were characterised at the molecular level only. Sequence and phylogenetic analysis using the ITS rRNA gene of these root-lesion nematodes revealed the presence of eight putative new species (spH1-H8) closely related to P. hippeastri. Here we describe two Florida representatives of the amphimictic root-lesion nematodes from Bahia grass (N1) and maidencane (N2), previously characterised by Inserra et al. in 1996 and Duncan et al. in 1999, as two new species phylogenetically related to P. hippeastri and named P. floridensis n. sp. and P. parafloridensis n. sp., respectively. The small round or oval (rarely rectangular and occasionally oblong) and enlarged spermatheca and the bluntly pointed or subacute tail with smooth and occasionally indented terminus separate P. floridensis n. sp. from P. parafloridensis n. sp., which has a quadrangular spermatheca and a subhemispherical or bluntly pointed tail with generally smooth and rarely indented terminus. However, these characters may overlap in some specimens making a morphological separation problematic without the use of molecular analysis. The close phylogenetic relationships shared by the species characterised in this study indicate that they are representatives of a P. hippeastri species complex.