<abstract xmlns="http://www.w3.org/1999/xhtml">

Soil samples collected during a survey for plant-parasitic nematodes in Tift County GA in summer 2017 were submitted for routine diagnosis of nematodes to the Extension Nematology Lab at the Department of Plant Pathology, University of Georgia, Athens, Georgia. Cyst nematodes recovered by centrifugal flotation technique were discovered in the samples from two research sites in a field with a history of tobacco and vegetable production. Cyst nematodes from tobacco (10 cysts/100 cm3 of soil) and vegetable (2 cysts/100 cm3 of soil) sites had similar morphological features. Morphology and morphometric measurements of the cysts and J2 (<xref ref-type="fig" rid="j_jofnem-2018-036_fig_001">Fig. 1A–C</xref>) were in agreement with those of <italic>Heterodera cyperi</italic> (<xref ref-type="bibr" rid="j_jofnem-2018-036_ref_001">Golden et al., 1962</xref>; <xref ref-type="bibr" rid="j_jofnem-2018-036_ref_002">Romero and López-Llorca, 1996</xref>). Measurements of J2 (<italic>n</italic> = 12) included the length (range = 443–494 μm, mean = 467.4 μm) and width (18.3–24.4 μm, 20.6 μm) of body, stylet (19.1–20.8 μm, 20.3 μm), tail (61.6.0–66.4 μm, 64.2 μm), body width at anus (11.9–14.1 μm, 12.8 μm), and hyaline tail terminus (22.7–29.2 μm, 26.3 μm). The lateral field of J2 had three lines. Cysts (<italic>n</italic> = 10; <xref ref-type="fig" rid="j_jofnem-2018-036_fig_001">Fig. 1C</xref>) were lemon-shaped, light to dark brown in color with protruding neck and vulval cone. The cysts had ambifenestrated vulval cone and no bullae was present. Morphometrics included body length excluding neck (370.5–714.4 μm, 555.7 μm); body width (165.6–411.1 μm, 310.9 μm); neck length (36.5–66.3 μm, 49.8 μm); fenestra length (26.3–42.5 μm, 35.8 μm), and fenestra width (19.1–31.5 μm, 23.8 μm). DNA was extracted from single cysts (<italic>n</italic> = 3) and internal transcribed spacer (ITS) of rRNA and partial cytochrome oxidase I (<italic>COI</italic>) genes were amplified with primers TW81/AB28 and Het-coxiF/Het-coxiR, respectively (<xref ref-type="bibr" rid="j_jofnem-2018-036_ref_005">Subbotin et al., 2001</xref>; <xref ref-type="bibr" rid="j_jofnem-2018-036_ref_003">Subbotin, 2015</xref>) and sequenced. The resulting sequences were deposited into the GenBank database (Accession no. MG825344 and MG857126) and also subjected to BLAST searches in the database. ITS sequence of <italic>H. cyperi</italic> showed 100% similarity (100% coverage) with that of a <italic>H. cyperi</italic> population from Spain (AF274388). <italic>COI</italic> sequence of <italic>H. cyperi</italic> showed 89% similarity (98% coverage) with that of <italic>H. guangdongensis</italic> (MF425735), and 88% similarity (83% coverage) with that of <italic>H. elachista</italic> (KC618473). The pathogenicity of <italic>H. cyperi</italic> was examined under greenhouse conditions using tobacco cv. K340, tomato cv. Tribute, cucumber cv. Thunder, and yellow nutsedge (<italic>Cyperus esculentus</italic> L.). 3-wk-old seedlings of the test plants were transferred into Deepot D25L cell containers (5-cm-diam. × 25.4-cm deep) filled with sterilized sand: sand: soil mixture (1:2) and then inoculated with 1,000 eggs and J2 of <italic>H. cyperi</italic>. The plants were grown for 90 d in a greenhouse before examination of roots and extraction of cysts from the soil. Results showed that the nematode failed to reproduce on tobacco, tomato, and cucumber whereas white females and mature cysts of <italic>H. cyperi</italic> were observed on yellow nutsedge roots (<xref ref-type="fig" rid="j_jofnem-2018-036_fig_001">Fig. 1E</xref>). The results confirmed that yellow nutsedeg was a host for the nematode, and tobacco, tomato, or cucumber were non-hosts. In the United States, <italic>H. cyperi</italic> was reported from Florida, North Carolina, and Arkansas (<xref ref-type="bibr" rid="j_jofnem-2018-036_ref_004">Subbotin et al., 2010</xref>) infecting <italic>Cyperus</italic> spp. Yellow nutsedge is considered a serious weed problem in many cropping systems including peanut, cotton, tobacco, and vegetable crops in the Southern United States. To our knowledge, this is the first report of <italic>H. cyperi</italic> infecting yellow nutsedge in Georgia.<fig id="j_jofnem-2018-036_fig_001" fig-type="figure">
<label>Figure 1</label>
<caption>
Photomicrographs of <italic>Heterodera cyperi</italic> from yellow nutsedge in Georgia. Whole body (A), the anterior region (B), and the posterior region (C) of J2. Cysts (D) recovered from the soil and the vulval cone of cyst with the ambifenestrate fenestra (E). A mature cyst (F) on the surface of yellow nutsedge root infected with the nematode.
</caption>
<graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_jofnem-2018-036_fig_001.jpg"></graphic>
</fig>

</abstract>

Soil samples collected during a survey for plant-parasitic nematodes in Tift County GA in summer 2017 were submitted for routine diagnosis of nematodes to the Extension Nematology Lab at the Department of Plant Pathology, University of Georgia, Athens, Georgia. Cyst nematodes recovered by centrifugal flotation technique were discovered in the samples from two research sites in a field with a history of tobacco and vegetable production. Cyst nematodes from tobacco (10 cysts/100 cm3 of soil) and vegetable (2 cysts/100 cm3 of soil) sites had similar morphological features. Morphology and morphometric measurements of the cysts and J2 (Fig. 1A–C) were in agreement with those of Heterodera cyperi (Golden et al., 1962; Romero and López-Llorca, 1996). Measurements of J2 (n = 12) included the length (range = 443–494 μm, mean = 467.4 μm) and width (18.3–24.4 μm, 20.6 μm) of body, stylet (19.1–20.8 μm, 20.3 μm), tail (61.6.0–66.4 μm, 64.2 μm), body width at anus (11.9–14.1 μm, 12.8 μm), and hyaline tail terminus (22.7–29.2 μm, 26.3 μm). The lateral field of J2 had three lines. Cysts (n = 10; Fig. 1C) were lemon-shaped, light to dark brown in color with protruding neck and vulval cone. The cysts had ambifenestrated vulval cone and no bullae was present. Morphometrics included body length excluding neck (370.5–714.4 μm, 555.7 μm); body width (165.6–411.1 μm, 310.9 μm); neck length (36.5–66.3 μm, 49.8 μm); fenestra length (26.3–42.5 μm, 35.8 μm), and fenestra width (19.1–31.5 μm, 23.8 μm). DNA was extracted from single cysts (n = 3) and internal transcribed spacer (ITS) of rRNA and partial cytochrome oxidase I (COI) genes were amplified with primers TW81/AB28 and Het-coxiF/Het-coxiR, respectively (Subbotin et al., 2001; Subbotin, 2015) and sequenced. The resulting sequences were deposited into the GenBank database (Accession no. MG825344 and MG857126) and also subjected to BLAST searches in the database. ITS sequence of H. cyperi showed 100% similarity (100% coverage) with that of a H. cyperi population from Spain (AF274388). COI sequence of H. cyperi showed 89% similarity (98% coverage) with that of H. guangdongensis (MF425735), and 88% similarity (83% coverage) with that of H. elachista (KC618473). The pathogenicity of H. cyperi was examined under greenhouse conditions using tobacco cv. K340, tomato cv. Tribute, cucumber cv. Thunder, and yellow nutsedge (Cyperus esculentus L.). 3-wk-old seedlings of the test plants were transferred into Deepot D25L cell containers (5-cm-diam. × 25.4-cm deep) filled with sterilized sand: sand: soil mixture (1:2) and then inoculated with 1,000 eggs and J2 of H. cyperi. The plants were grown for 90 d in a greenhouse before examination of roots and extraction of cysts from the soil. Results showed that the nematode failed to reproduce on tobacco, tomato, and cucumber whereas white females and mature cysts of H. cyperi were observed on yellow nutsedge roots (Fig. 1E). The results confirmed that yellow nutsedeg was a host for the nematode, and tobacco, tomato, or cucumber were non-hosts. In the United States, H. cyperi was reported from Florida, North Carolina, and Arkansas (Subbotin et al., 2010) infecting Cyperus spp. Yellow nutsedge is considered a serious weed problem in many cropping systems including peanut, cotton, tobacco, and vegetable crops in the Southern United States. To our knowledge, this is the first report of H. cyperi infecting yellow nutsedge in Georgia.
Figure 1

Photomicrographs of Heterodera cyperi from yellow nutsedge in Georgia. Whole body (A), the anterior region (B), and the posterior region (C) of J2. Cysts (D) recovered from the soil and the vulval cone of cyst with the ambifenestrate fenestra (E). A mature cyst (F) on the surface of yellow nutsedge root infected with the nematode.

First Report of the Yellow Nutsedge Cyst Nematode, <italic>Heterodera cyperi</italic>, in Georgia, U.S.A.

Journal of Nematology

This work is licensed under the Creative Commons Attribution 4.0 International License.

First Report of the Yellow Nutsedge Cyst Nematode, , in Georgia, U.S.A.

running-head

First Report of the Yellow Nutsedge Cyst Nematode: Abolfazl et al.

Soil samples collected during a survey for plant-parasitic nematodes in Tift County GA in summer 2017 were submitted for routine diagnosis of nematodes to the...

First Report of the Yellow Nutsedge Cyst Nematode, Heterodera cyperi, in Georgia, U.S.A.

Publié en ligne: 17 oct. 2018

Pages: 456 - 458

DOI: https://doi.org/10.21307/jofnem-2018-036

Mots clés
Detection, Georgia, Heterodera cyperi

© 2018 Abolfazl Hajihassani et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

First Report of the Yellow Nutsedge Cyst Nematode, Heterodera cyperi, in Georgia, U.S.A.

Publié en ligne: 17 oct. 2018

Pages: 456 - 458

DOI: https://doi.org/10.21307/jofnem-2018-036

Mots clésDetection, Georgia, Heterodera cyperi

© 2018 Abolfazl Hajihassani et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Mots clés
Detection, Georgia, Heterodera cyperi