plant-parasitic nematodes associated with wheat in kohgiluyeh and ...

Parasitic nematodes associated with wheat 131
Research Note
PLANT-PARASITIC NEMATODES ASSOCIATED WITH WHEAT
IN KOHGILUYEH AND BOYER-AHMAD PROVINCE, IRAN
M. Abdollahi*
ABSTRACT
This study was conducted during 2007-2008 to determine the genera/species of
plant parasitic nematodes associated with wheat in cold regions of the
Kohgiluyeh and Boyer-Ahmad province of Iran. Plant parasitic nematode
population densities were determined in 100 soil and root samples collected
from 21 cereal growing districts of the province. Seven genera of plantparasitic
nematodes, including Pratylenchus, Helicotylenchus, Heterodera,
Tylenchorhynchus, Xiphinema and Ditylenchus were found associated with
cereal crops. The most important damaging plant-parasitic nematodes
detected, were Pratylenchus (16.8%) and Helicotylenchus (14.8%). Their
population densities per 50g of root were above damaging levels in some of
the cereal fields surveyed.
KEYWORDS: Triticum aestivum; Heterodera; Pratylenchus; Xiphinema;
Ditylenchus; population; Iran
INTRODUCTION
Cereals, such as wheat, oats and barley, are among the major staple crops
of economic importance the worldover. These crops are parasitized by many
pathogens and pests including plant parasitic nematodes. It is estimated that
nematodes cause 85 billion dollars crop losses worldwide each year (12).
Wheat is a major field crop in Kohgiluyeh and Boyer-Ahmad province being
cultivated on 205,000 hectares with 282 thousand metric ton production
annually (2).
Nevertheless, little information is available about plant-parasitic nematodes in
cereal fields of the Kohgiluyeh and Boyer-Ahmad province, a survey of plant
parasitic nematodes was carried out to (i) identify the plant-parasitic
nematodes associated with cereal-producing fields of the province, and (ii)
determine the frequency and population density of plant-parasitic nematodes.
Identification of nematodes was based on morphological characteristics.
*Department of Plant Protection, Yasouj University, Yasouj, Iran.
J. Agric. Res., 2010, 48(1)

132 M. Abdollahi.
MATERIALS AND METHODS
This study was conducted in the Department of Plant Protection, Yasouj
University, Yasouj, Iran during 2007-08. For this purpose a survey on the
plant parasitic nematodes of cereal fields was carried out in cold regions of
the Kohgiluyeh and Boyer-Ahmad province. The soil and cereal root samples
were collected 21 cereal growing districts (Fig). During first week of June
2007 and 2008, around the last irrigation period, soil and root samples were
collected by walking zig-zag of 100 irrigated wheat and barley fields. In each
field, ten locations were randomly selected and one plant in each location
was sampled. Soil around the roots and the roots were collected. The
collected soil samples from each field were mixed and a composite sample of
approximately two kilogram was placed in a plastic bag. The collected roots
from each field were also placed in a separate plastic bag. All bags,
containing soil samples and the roots, were kept in ice-chest during
transportation and refrigerated at 4 o C in the laboratory until processing.
Fig. Sampling locations in Kohgiluyeh and Boyer-Ahmad province, Iran.
The soil samples were assayed for the presence of plant-parasitic
nematodes using sieving and sugar-flotation methods. A set of nested
seives, 20 and 325 mesh was used to extract nematodes from the soil
samples (7).
The roots were washed with tap water and examined for the presence of
nematodes. Symptoms on root caused by the plant-parasitic nematodes,
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Parasitic nematodes associated with wheat 133
were recorded under Stereobinocular microscope. The roots were dipped into
pieces of 1-3 mm. The nematodes were extracted from composite root
samples by mist-extraction method for 10-days (8).
The nematodes were killed in hot water bath and fixed in 2 percent
formaldehyde. Nematodes were processed for dehydration by Seinhorst’s
method and mounted on glass slides in anhydrous glycerin (13). Identification
of nematode genera and species were based on the morphology with the
help of keys (4, 5, 6, 14). Identification of cyst nematodes was based on the
type of cone tops of cysts mounted in Canada balsam (10) and
characteristics of J2s. The exact number of nematodes in each genus was
assessed.
RESULTS AND DISCUSSION
Plant parasitic nematodes were detected in all soil and root samples. Among
nematodes, the species belong to the genera Pratylenchus and
Helicotylenchus included P. brachyurus (Godfrey) Filipjev and Stekhoven, P.
crenatus Loof, P. neglectus (Rensch) Filipjev and Stekhoven, P. penetrans
(Cobb) Filipjev and Stekhoven, P. thornei Sher and Allen, H. digonicus
Darling and Thorne and H. dihystera (Cobb) Sher were the most frequent.
Other nematodes of common occurrence were Ditylenchus dipsaci (Kuhn)
Filipjev, Heterodera filipjevi (Madzhidov) Stelter, Tylenchorhynchus claytoni
Steiner, T. nudus Allen, T. vulgaris Upadhyay et al., Xiphinema Cobb.,
Criconemoides, Paratylenchus projectus Jenkins and Trichodorus Cobb
(Table).
Frequency of the genera Pratylenchus, Helicotylenchus, Xiphinema,
Heterodera J2, Ditylenchus, Tylenchorhynchus and other nematodes were
16.80, 14.80, 8.00, 7.10, 5.20, 4.50 and 41.90 percent, respectively (Table
1). The population density ranged from 81 (Shabliz) to 183 (Madavan) per
100 cm 3 of soil.
This survey provides information on occurrence and density of plant parasitic
nematodes associated with wheat and barley crops cultivated in Kohgiluyeh
and Boyer-Ahmad province. The results of this study indicate that some plant
parasitic nematodes especially the cereal cyst, spiral and root lesion
nematodes, the endoparasites, were found widely distributed in cereal fields
of the province which are of economic importance and are considered
serious pests of wheat and barley crops (9). The prominence of Pratylenchus
with high population density in soil as well in roots differed from others. Sixtyfive
percent of collected cyst nematodes were identified as H. filipjevi (1).
J. Agric. Res., 2010, 48(1)

134 M. Abdollahi.
Table 1. Frequency and population of plant parasitic nematodes associated with
Triticum aestivum in Kohgiluyeh and Boyer-Ahmad province. Iran.
Locality with No. of Ditylenchus Helicotylenchus Heterodera Cyst Heterodera J2
samples 100 cc soil 50g root
Abchendar-2 8 (0-15) 8 (0-15) 20 5 (3-5) 34 (16-32)
5.00% 5.00% (21-29) 3.30% 22.40%
Abmoore-7 8 (0-24) 2 (9-33) 22 1 (0-4) 4 (0-12)
5.80% 14.20% (10-45) 80.00% 2.60%
Babakan-3 3 (0-10) 22 (6-45) 35 1 (0-2) 6 (3-10)
2.00% 13.10% (20-45) 0.60% 3.80%
Benestan-4 6 (0-12) 15 (9-21) 22 3 (1-5) 11 (0-26)
5.30% 14% (14-39) 2.70% 10.40%
Barb-e-Kalat-3 7 (6-8) 18 (8-24) 34 0 (0-1) 6 (1-15)
7.20% 17.80% (23-55) 30.00% 6.30%
Dasht-e-Room-5 5 (0-9) 17 (0-28) 36 3 (0-7) 20 (7-35)
3.40% 11.40% (20-50) 2.20% 13.30%
Huseinabad-6 4 (0-5) 20 (13-28) 32 1 (0-3) 9 (0-21)
3.20% 16.30% (20-44) 0.80% 7.30%
Kakan-7 6 (0-24) 23 (2-46) 33 2 (2-6) 8 (0-18)
4.30% 15.20% (20-46) 1.40% 5.00%
Kaloos-6 8 (5-13) 20 (4-48) 33 1 (0-3) 4 (0-14)
3.10% 15.90% (20-56) 0.80% 3.40%
Kaveshk-7 9 (2-17) 23 (10-56) 27 3 (0-6) 7 (0-19)
6.30% 15.80% (13-43) 1.80% 5.10%
Madavan-2 12 (9-14) 16 (7.25) 40 1 (0-2) 30 (0-60)
6.30% 8.70% (30-40) 0.50% 16.40%
Margoon-5 11 (0-26) 17 (6-35) 35 2 (1-5) 8 (0-14)
7.70% 11.70% (18-50) 1.60% 5.30%
Nagharehkhaneh-8 6 (0-14) 19 (12-34) 30 2 (0-6) 11 (0-32)
4.60% 14.80% (20-45) 1.50% 8.60%
Pataveh-3 11 (3-16) 24 (13-36) 38 4 (2-7) 9 (0-26)
9.90% 21.30% (30-44) 3.90% 8.40%
Poshtkooh-7 5 (0-12) 20 (4-37) 31 1 (0-3) 6 (0-23)
3.50% 13.40% (21-43) 0.80% 4.00%
Sepidar-7 8 (0-14) 25 (9-46) 24 4 (1-8) 16 (0-28)
4.60% 15.00% (12-34) 2.60% 9.80%
Servak-8 10 (0-27) 28 (7-56) 32 3 (0-8) 13 (0-24)
6.00% 16.80% (21-49) 2.10% 8.10%
Shabliz-1 9 13 19 6 2
11.10% 16.00% 7.40% 2.50%
Tang-e-Sorkh-7 9 (0-22) 24 (11-35) 37 3 (0-6) 10 (0-18)
6.00% 15.90% (22-60) 2.20% 6.30%
Tomonak-1 7 18 1 6
6.60% 17.00% 54 0.90% 5.70%
Tootnadeh-1 0 48 2 0
0.00% 35.00% 20 1.50% 0.00%
Total-100 738 2097 233 1006
5.2% 14.8% 3122 1.6% 7.1%
Locality with no. of Pratylenchus Tylenchorhynchus Xiphinema Other nematodes
samples 100 cc soil 50g root 100 cc soil 50g root
Abchendar-2 19 (16-21) 32 6 (0-11) 8 10 (8-11) 64 (59-64)
12.20% (28-35) 3.60% (5-11) 6.30% 42.20%
Abmoore-7 17 (8-30) 35 5 (0-11) 15 12 (10-15) 73 (65-90)
12.30% (14-62) 3.30% (6-27) 8.70% 52.40%
Babakan-3 31 (6-58) 50 15 (3-23) 12 12 (8-17) 75 (67-82)
18.60% (34-60) 8.90% (9-16) 7.30% 45.70%
Benestan-4 19 (5-27) 36 1 (0-5) 19 12 (8-15) 38 (15-60)
18.10% (22-43) 1.20% (5-27) 11.80% 36.50%
Barb-e-Kalat-3 23 (17.33) 53 8 (0-17) 23 9 (6-11) 29 (20-48)
22.40% (44-70) 8.20% (16-34) 8.90% 28.90%
Dasht-e-Room-5 24 (7-45) 45 8 (0-15) 16 9 (4-15) 61 (49-80)
16.40% (22-54) 5.50% (7-45) 6.60% 41.30%
Huseinabad-6 18 (5-30) 39 5 (0-12) 14 12 (6-22) 53 (23-76)
15.10% (18-55) 4.00% (6-32) 9.70% 43.70%
Kakan-7 23 (4-36) 40 10 (0-22) 16 12 (5-16) 67 (54-80)
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Parasitic nematodes associated with wheat 135
15.20% (19-54) 6.50% (9-26) 8.00% 44.50%
Kaloos-6 25 (12-45) 45 1 (0-4) 17 9 (5-12) 59 (40-78)
19.80% (26-73) 0.80% (7-26) 7.00% 46.20%
Kaveshk-7 18 (6-37) 36 4 (0-11) 14 14 (9-16) 65 (39-85)
12.90% (22-55) 2.80% (8-26) 9.60% 45.60%
Madavan-2 46 (37-55) 52 8 (4-12) 10 14 (12-15) 57 (49-65)
25.10% (40-63) 4.40% (8-12) 7.40% 31.10%
Margoon-5 34 (18-44) 39 2 (0-5) 17 13 (5-23) 60 (34-80)
23.00% (0-66) 1.10% (10-22) 8.60% 41.00%
Nagharehkhaneh-8 27 (22-38) 40 5 (0-18) 17 13 (7-20) 45 (25-84)
21.50% (27-61) 4.30% (11-34) 9.00% 35.80%
Pataveh-3 16 (7-28) 37 3 (0-7) 11 8 (5-11) 35 (28-40)
14.70% (28-50) 3.00% (6-15) 7.20% 31.70%
Poshtkooh-7 30 (11-48) 46 9 (0-18) 17 10 (2-20) 69 (49-80)
20.10% (32-60) 5-90% (9-25) 6-90% 45.50%
Sepidar-7 26 (11-41) 42 7 (0-23) 17 11 (6-15) 70 (45-85)
15.70% (19-52) 4.20% (6-31) 6.50% 41.80%
Servak-8 22 (7-48) 44 10 (0-23) 18 11 (5-22) 66 (44-82)
13.50% (25-72) 6.30% (9-29) 7.00% 40.20%
Shabliz-1 6 23 11 10 14 20
7.40% - 1360% - 17.30% 24.70%
Tang-e-Sorkh-7 24 (6-39) 46 5 (0-18) 13 12 (8-20) 65 (43-80)
15.50% (29-85) 3.50% (5-27) 8.00% 42.70%
Tomonak-1 26 61 8 30 11 29
24.50% - 7.50% - 10.40% 27.40%
Tootnadeh-1 22 51 13 11 8 44
16.10% - 9.50% - 5.80% 32.10%
Total-100 2382 4188 630 1555 1132 5933
16.8% - 4.5% - 8.0% 41.9%
Nevertheless, because of little work done in the province, damaging
threshold for root lesion nematodes is unknown. The population density
encountered in this survey may present a potential risk to cereal crops.
Further research is required to (i) determine the significance of these
nematodes on cereals and (ii) determine their interaction with other soil
pathogens. This survey provides important background information for
planning and administering nematode management strategies in cereal fields
of Kohgiluyeh and Boyer-Ahmad province.
ACKNOWLEDGEMENT
Financial support under grant No. 1274 from Research and Technology
Office of Yasouj University is acknowledged. I also thank my family members
for their patience during course of investigation.
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