© Benaki Phytopathological Institute
Hellenic Plant Protection Journal
12:
97-107, 2019
DOI 10.2478/hppj-2019-0010
1
Department of Plant Protection, College of Agricul-
ture, Shahid Chamran University of Ahvaz, Ahvaz,
Iran.
* Corresponding author:
Plant parasitic nematodes fauna in citrus orchards in
Khuzestan province, Southwestern Iran
P. Eisvand
1
, R. Farrokhi Nejad
1
and S. Azimi
1
*
Summary
During a survey on the biodiversity of plant-parasitic nematodes in citrus orchards of Khuz-
estan province (Southwestern Iran), 97 root and soil samples were collected. Nematodes were extrac-
ted and identified using morphological and morphometric diagnostic characters. Six nematode spe-
cies were identified, namely:
Helicotylenchus abunaamai, H. crenacauda, Pratylenchus allius, P. musii, Psi-
lenchus hilarulus
and
Tylenchulus semipenetrans
. Except
T. semipenetrans
, the remaining five species
were found only in the rhizosphere of citrus, not in citrus roots, and their pathogenicity on citrus plants
was not further studied. This is the first record of
P. allius
and
P. musii
for the nematode fauna in Iran.
H. crenacauda
is a new record for the nematode fauna in the Khuzestan province and is reported for
the first time in citrus orchards in Iran. To our knowledge, this is the first report of
H. abunaamai
in cit-
rus orchards worldwide.
Additional keywords:
citrus, first record, morphology, morphometric, plant-parasitic
2005).
R. citri
Machon and Bridge (1996) was
found in citrus roots in Indonesia and was as-
sociated with very severe necrosis and root
destruction (Machon and Bridge, 1996).
Pratylenchus coffeae
(Zimmermann, 1898)
Filipjev and Schuurmans Stekhoven, 1941,
P. brachyurus
(Godfrey, 1929) Filipjev and
Schuurmans Stekhoven, 1941 and
P. vulnus
Allen and Jensen (1951) are three species of
lesion nematodes associated with the citrus
tree. Also,
Belonolaimus longicaudatus
Rau
(1958) causes damage to citrus. Root-knot
nematodes (
Meloidogyne
spp.) are able to at-
tack citrus and are confined to prevent dis-
semination. Pathogenic species of root-knot
nematode were reported from Taiwan and
New Delhi (Duncan, 2005).
Many populations of
Xiphinema brevicol-
lum
Lordello and Da Costa (1961) have been
associated with the decline of grapefruit
trees in Sudan (Yassin, 1974).
Paratrichodorus
lobatus
(Colbran, 1965) has also been found
in high numbers in citrus nurseries in Austra-
lia (Stirling, 1976).
Hemicycliophora arenaria
(Raski, 1958) is a species native to plants in
the southern California that causes damage
in citrus nurseries (McElroy
et al.,
1966).
Ca-
loosia nudata
(Colbran) Brzeski, 1974 causes
similar symptoms on citrus in Australia (Col-
bran, 1963).
Introduction
Citrus is indigenous to southeastern Asia
but has existed in Mediterranean basin for
centuries. Species of citrus have great im-
portance in some Mediterranean regions
(Duarte
et al.,
2016). Iran is the eighth largest
producer of citrus in the world. In 2017, Irani-
an citrus fruit production reached 4,067,000
tons (FAOSTAT, 2017). Khuzestan province is
one of the major citrus-producing regions in
the country.
A wide range of plant-parasitic nema-
todes has been associated with the citrus
rhizosphere but only some species cause
damage to the trees (Verdejo-Lucas and
McKenry, 2004). The citrus nematode (
Ty-
lenchulus semipenetrans
Cobb, 1913) causes
a slow decline of citrus all around the world
and restricts citrus fruit production under a
wide spectrum of environmental conditions
(Duncan, 2005). Spreading decline is a seri-
ous disease of citrus caused by
Radopholus
similis
(Cobb, 1893) Thorne, 1949 that only
occurs in Florida’s central ridge (Duncan,
