Pratylenchus hippeastri n. sp. (Nematoda: Pratylenchidae) from amaryllis in Florida with notes on P. scribneri and P. hexincisus

Abstract

A new root-lesion nematode Pratylenchus hippeastri n. sp. is described from amaryllis (Hippeastrum spp.) in Florida. The new species is characterised by a combination of the following morphological features of females: slender body, flat, plain and smooth face, head with two lip annuli, an incomplete third annulus, and with second lip annulus thicker than first, ellipsoidal stylet knobs, rectangular empty spermatheca with large round cavity, and conoid tail with bluntly pointed terminus usually showing a ventral constriction, or subhemispherical and smooth. The ranges of morphometric characters of P. hippeastri n. sp. overlap with those of P. scribneri and P. hexincisus. These three species also share some morphological and biological features such as two lip annuli, an empty spermatheca and similar lateral fields, but differ in the morphology of head patterns (smooth face in P. hippeastri n. sp. vs divided face in the others) and tail termini (hemispherical and subhemispherical in P. scribneri and subdigitate in P. hexincisus vs bluntly pointed in P. hippeastri n. sp.). A reference population of P. scribneri from Ohio and one of P. hexincisus from Tennessee were obtained during the course of unsuccessful attempts to recover P. scribneri at the type locale in Tennessee. The D3 rDNA sequences of the reference populations matched GenBank sequences for these two species. Small morphological differences between the P. scribneri population from Ohio and the P. scribneri lectotype occurred in the shape of stylet knobs (ellipsoidal vs round) and spermatheca (round with a central cavity vs oblong) and also in the length of the pharyngeal overlap (longer in the reference population). These morphological differences cast doubt about the identity of the lectotype, which may be P. hexincisus. New morphological details were obtained for P. hexincisus from Tennessee, which included a divided face, an almost rectangular empty spermatheca with a central cavity and subdigitate tail termini. Based on our phylogenetic inferences from DNA sequences P. hippeastri n. sp. is more closely related to P. zeae and a Florida population of P. loosi than to P. scribneri or P. hexincisus.Amaryllis (Hippeastrum spp.) are flowering ornamentals that beautify gardens throughout Florida and warm states in the United States. These bulbous plants are native in Tropical America. Intense breeding programmes by amaryllis growers have improved the size, colour and shape of the flowers, and resulted in a great number of varieties that are marketed by ornamental industries in many

Molecular and morphological characterization of the amaryllis lesion nematode, Pratylenchus hippeastri (Inserra et al., 2007), from California

“…Based upon the unambiguous similarity of all examined DNA markers with those previously reported for the species by several authors ( Gozel et al, 2007 ; Subbotin et al, 2008 ; DeLuca et al, 2010 ; Wang et al, 2016 ; Knoetze et al, 2019 ; Shokoohi, 2019 ) and the morphological data by Inserra et al (2007) , we identify this isolate as Pratylenchus hippeastri ( Inserra et al, 2007 ). To our knowledge this represents the first report of the amaryllis lesion nematode ( Pratylenchus hippeastri ) in California as well as the first report on grapevine.…”

“…Pratylenchus hippeastri , also known as the amaryllis lesion nematode, has been previously reported only from Florida ( Gozel et al, 2007 ; DeLuca et al, 2010 ), China ( Wang et al, 2016 ) and more recently from South Africa ( Shokoohi, 2019 ; Knoetze et al, 2019 ). Currently, the host range of this nematode is narrow, being reported only on three hosts, amaryllis, bromeliads, and apples ( Gozel et al, 2007 ; DeLuca et al., 2010 ; Wang et al, 2016 ; Knoetze et al., 2019 ) and from the rhizosphere around Cape Willow trees, Salix mucronata ( Shokoohi, 2019 ). This report represents the first detection of this species on grapevines in California, thus representing the second report of this nematode in North America.…”

Characterization of Pratylenchus crenatus and P. neglectus (Nematoda: Pratylenchidae) associated with wheat crop

“…Ribosomal DNA (rDNA) sequence has been shown to be a reliable genetic marker for identifi cation purposes, and a powerful tool to analyze genetic variation. The 28S D2/D3 rDNA fragment has been used frequently to characterise Pratylenchus populations (Handoo et al, 2001;Al-Banna et al, 2004;De Luca et al, 2004;Inserra et al, 2007;. Previously P. neglectus has been found under the rhizosphere of Brassica (Kumari, 2012) and Pratylenchus sp.…”

Nematod taksonomisinde kullanılan moleküler markörler

“…ITS bölgelerinin dizileri kullanılarak birçok bitki paraziti nematod türünün tanımlanması yapılmıştır (Subbotin et al, 2001;Floyd et al, 2002;Reid et al, 2003;Gözel et al, 2006a;Inserra et al, 2007). 18S rRNA geninin dizi analizleri (Floyd et al, 2002) ve 28S rDNA'nın D2-D3 bölgeleri Tylenchidae (Subbotin et al, 2006) ve Longidoridae He et al, 2005) familyalarına ait türlerin tespitinde kullanılmıştır.…”