Meloidogyne daklakensisn. sp. (Nematoda: Meloidogynidae), a new root-knot nematode associated with Robusta coffee (Coffea canephoraPierre ex A. Froehner) in the Western Highlands, Vietnam

Abstract

The root-knot nematode species Meloidogyne daklakensis n. sp. was discovered on the roots of Robusta coffee (Coffea canephora Pierre ex A. Froehner) in Dak Lak Province, Vietnam. This species is characterized by the females having rounded or oval perineal patterns, smooth, regular, continuous striae, and reduced lateral lines. The dorsal arch is low, rounded and encloses a quite distinct vulva and tail tip. The stylet is normally straight with well-developed and posteriorly sloped knobs. The males have a rounded cap that extends posteriorly into the lip region. The procorpus is outlined distinctly, and is three times longer than the metacorpus. The metacorpus is ovoid, with a strong valve apparatus. The species closely resembles M. marylandi, M. naasi, M. ovalis, M. panyuensis, M. lopezi, M. mali and M. baetica in the perineal pattern of the females, and the morphology of the males and the second-stage juveniles. Nonetheless, it can be differentiated from other species by a combination of morphometric, morphological and molecular characteristics. Phylogenetic analysis was conducted based on the internal transcribed spacer (ITS) and 28S rDNA as well as the region between the cytochrome c oxidase I (COI) and cytochrome c oxidase II (COII) mitochondrial genes. Herein, this nematode is described, illustrated, and designated as a new species, Meloidogyne daklakensis sp. n., based on morphometric, morphological and molecular analyses.

Multigene phylogeny of root-knot nematodes and molecular characterization of Meloidogyne nataliei Golden, Rose & Bird, 1981 (Nematoda: Tylenchida)

“…16 using same gene and but larger number of species confirmed the presence of these three major clades within Meloidogyne . Several other genes were also successfully used for reconstruction of Meloidogyne single gene phylogeny: the ITS rRNA 3,11,17–24 , the D2-D3 of 28S rRNA 3,11,15,18–25 ; the RNA polymerase II gene ( rpb1 ) 26,27 , the region between the COII and 16S rRNA genes of mtDNA 3,20,22–24,28 ; hsp90 29 , COI 3,15,16,24,30,31 and IGS rRNA 32 , COII 15 . However, it has been shown by Hugall et al .…”

“…Their worldwide distribution and broad host range (parasitizing nearly every species of higher plant) contribute to their status as the most economically important group of plant-parasitic nematodes 1 . Nearly one hundred valid species are in the genus 2,3 , most of which are prevalent in warm temperate and tropical regions. Only six Meloidogyne species, namely M .…”

A new root-knot nematode, Meloidogyne moensi n. sp. (Nematoda: Meloidogynidae), parasitizing Robusta coffee from Western Highlands, Vietnam

“…Root-knot nematode species are normally identified using morphological features and morphometrics of the female, the second-stage juveniles, and the male such as the structure of the labial region, stylet, basal knobs, and the perineal patterns of mature females (Blok & Powers, 2009; Eisenback, 1985). Molecular approaches, that have been using in identification of Meloidogyne species, can strongly support morphological approaches (Carneiro et al, 2014; Charchar et al, 2008; Janssen et al, 2017; Hummrey-Pereira et al, 2014; Subbotin et al, 2006; Trinh et al, 2018).…”

“…To date, eighteen species of the genus Meloidogyne have been reported in the world, namely M. exigua Goldi, 1887, M. africana Whitehead, 1960, M. arabicida Lopez, 1989, M. arenaria (Neal, 1889) Chitwood, 1949, M. coffeicola Lordello and Zamith, 1960, M. daklakensis Trinh, Le, Nguyen, Nguyen, Liebanas and Nguyen, 2018, M. decalineata Whitehead, 1968, M. hapla Chitwood, 1949, M. incognita (Kofoid and White, 1919) Chitwood, 1949, M. inornata Lordello, 1956, M. izalcoensis Carneiro, Almeida, Gomes and Hernandez, 2005, M. javanica (Treub, 1885) Chitwood, 1949, M. kikuyensis de Grisse, 1960, M. konaensis Eisenback, Bernard and Schmitt, 1994, M. mayaguensis Rammah and Hirschmann, 1988, M. megadora Whitehead, 1968, M. oteifae Elmiligy, 1968, M. paranaensis Carneiro, Carneiro, Abrantes, Santos and Almeida, 1996 (Souza, 2008; Trinh et al, 2018). Root-knot nematodes are considered the most damaging plant parasitic nematode on coffee in Vietnam (Trinh et al, 2009; 2013; Wiryadiputra & Tran, 2008).…”

“…The coffee associated species, M. incognita , has been mainly documented in the country (Bell et al, 2018; Nguyen & Nguyen, 2000; Trinh et al, 2009; 2013; Wiryadiputra & Tran, 2008). Subsequently, four other Meloidogyne species have also been found in coffee plantations in Vietnam, namely M. exigua, M. coffeicola, M. hapla , and M. daklakensis (Bell et al, 2018; Trinh et al, 2013; Trinh et al, 2018).…”