Yam (
Nematode populations used in this study were obtained soil and tuber sampling undertaken across agro-ecological zones in Ghana and Nigeria during surveys conducted between 2012 and 2015 (Table 1). Nematodes from 195 yam rhizosphere and 400 tubers were recovered using the Whitehead tray immersion technique (Hooper et al., 2005). Extraction from rhizosphere was set using 100 ml soil sub-samples including all roots retrieved from soil per sample. Tubers were peeled using a kitchen peeler, chopped and three sub-samples of 5 g tuber peels were used for the extraction (Coyne et al., 2006). Extracted nematodes were collected on 28 μm sieves, rinsed and divided: one part was heat killed and fixed in 4% formalin, the other part was fixed directly in DESS solution (Yoder et al., 2006). In total, 127 nematodes, including 75 specimens from yam tubers, were used for species identification.
Country | Region* | Districtα | Code | Species | N | Longitude (°) | Latitude (°) | Altitude (m) | HostT | D2-D3 |
|
Ghana | Brong Ahafo | Atebubu | Atebubu PS 1 |
|
1 | 0.98598 | 7.75467 | 151 |
|
||
Atebubu-Amantin | Ahontor 1 |
|
2 | 0.96798 | 7.79126 | 139 |
|
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Tintare 2 |
|
2 | 0.90484 | 7.72486 | 159 |
|
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Kintampo North | Bablioduo K 1 |
|
3 | 1.86789 | 8.0352 | 265 |
|
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Kintampo S 1 |
|
6 | 1.84078 | 8.14824 | 206 |
|
MT362906, MT362907 | MT952194, MT952195 | |||
Northern | East Gonja | Adamupe 1 |
|
3 | 0.51155 | 8.49292 | 176 |
|
MT362896 | MT949472 | |
Bagabaga 1 |
|
2 | 0.61344 | 8.55865 | 157 |
|
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Kitoe 1 |
|
1 | 0.49596 | 8.4655 | 189 |
|
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Tolon | Kpalsogu 2 |
|
7 | 1.01323 | 9.39844 | 171 | D. rotundata | ||||
Kukuo 1 |
|
4 | 1.02533 | 9.41156 | 171 |
|
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Kukuo 2 |
|
2 | 1.02556 | 9.41114 | 170 |
|
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Kukuo 3 |
|
2 | 1.02556 | 9.41114 | 170 |
|
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Wala 1 |
|
2 | 1.24929 | 9.63993 | 124 |
|
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Country | State* | LGAα | Code | Species | N | Longitude (°) | Latitude (°) | Altitude (m) | HostT | D2-D3 |
|
Nigeria | Abia | Umuahia | Umudike 1 |
|
1 | 7.53057 | 5.48212 | 108 |
|
||
Umudike 2 |
|
2 | 7.53057 | 5.48212 | 108 |
|
|||||
Umuahia North | Umuagu 1 |
|
1 | 7.44739 | 5.61234 | 90 |
|
||||
Anambra | Anambra East | Igbariam 1 |
|
1 | 6.96508 | 6.30112 | 69 |
|
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Benue | Otukpo | Otukpo 1 |
|
12 | 8.13327 | 7.19212 | 196 |
|
MT362904, KY828292 | MT951588, KY828320 | |
Ekiti | Irepodum-Ifelodum | Araromi 1 |
|
2 | 5.19352 | 7.67682 | 450 |
|
|||
Enugu | Udi | Amoka 1 |
|
7 | 7.39581 | 6.55556 | 388 |
|
|||
Imo | Owerri | Mbaise 1 |
|
14 | 7.03433 | 5.48433 | 233 |
|
MT362898, MT362899, MT362900, MT362901 | MT949474, MT949475 | |
Kogi | Idah | Ega 1 |
|
1 | 6.72912 | 7.10123 | 29 |
|
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Ega 2 |
|
3 | 6.72912 | 7.10123 | 29 |
|
|||||
Ega 3 |
|
1 | 6.72912 | 7.10123 | 29 |
|
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Ijumu | Okejumu 1 |
|
5 | 5.93338 | 7.84627 | 495 |
|
||||
Nasarawa | Lafia | Rimiuka 1 |
|
21 | 8.51598 | 8.49365 | 175 |
|
|||
Rimiuka 2 |
|
6 | 8.51598 | 8.49365 | 175 |
|
|||||
Nasarawa Eggon | Eggon 1 |
|
8 | 8.5409 | 8.71445 | 271 |
|
MT362897 |
Kintampo S1: Two species were recorded from the same sample
Nematodes from 27 samples fixed in formalin were processed to anhydrous glycerin following the glycerin-ethanol method (Seinhorst, 1959) as modified by De Grisse (1969). Permanent slides were prepared and used to record morphometrics and morphological features (Castillo and Vovlas, 2007; Inserra et al., 2007) using an Olympus BX51 DIC microscope equipped with a Nikon digital camera. Additional morphological and morphometrical data were recorded from temporary slides made from DESS fixed specimens, before DNA extraction (see Table 1).
Following morphological identification, the same individual nematodes were picked from temporary slides and used for extraction of genomic DNA using a quick alkaline lysis protocol (Janssen et al., 2016). DNA was amplified by preparing 24 μl PCR master mix comprising 16 μl double sterilized distilled water, 2.5 μl 10x buffers, 2 μl MgCl2, 0.05 μl of dNTP (10 mM), 1 μl of reverse and forward primers, 0.05 μl of Toptaq and 2 μl of nematode template DNA. The primer set D2A (5’–ACA AGT ACC GTG AGG GAA AGT TG–3’) and D3B (5’–TCG GAA GGA ACC AGC TAC TA–3’) (Subbotin et al., 2006) was used for amplification of the D2-D3 expansion regions of 28 S rDNA gene and the cytochrome c oxidase subunit 1 (
PCR products were electrophoretically separated on a 1% agarose gel and stained with ethidium bromide. PCR products were purified using the Wizard® SV Gel and PCR Clean-Up System Kit (Promega, the Netherlands) as described in the manufacturer’s instructions and sequenced by Macrogen Inc. (the Netherlands) in forward and reverse directions. Consensus sequences were assembled using GENEIOUS 9.15 (Biomatters;
Both D2-D3 of 28 S rDNA and
From the rhizosphere,
Proportion of
Measurements of thirteen
Sample | Atebubu PS 1 | Ahontor 1 | Tintare 2 | Bablioduo K 1 | Kintampo S 1 | Kpalsogu 2 | Kukuo 1 |
---|---|---|---|---|---|---|---|
N | 1♀* | 2♀♀ | 2♀♀ | 3♀♀ | 3♀♀ | 7♀♀♀* | 4♀♀ |
L | 507 | 566-543 | 518-532 | 556±16.9 (538-572) | 487±44.7 (451-537) | 470±38 (390-504) | 501±13.6 (488-520) |
a | 16.5 | 24.0-21.0 | 18.9-21.9 | 24.4±5.4 (19.6-30.2) | 18.2±0.72 (17.4-18.7) | 16.7±2.3 (14.1-21.1) | 19.9±3.3 (15.8-22.6) |
b | 6.2 | 4.6-4.6 | 5.3-5.7 | 5.8±0.64 (5.3-6.2) | 5.2±0.9 (4.2-5.8) | 4.7±0.21 (4.5-4.8) | 5.2±1.2 (4.2-6.9) |
b' | 4.3 | 3.8-4.1 | 4.2-4.7 | 4.1±1.0 (3.4-5.3) | 3.7±0.74 (3.1-4.5) | 3.5±0.07 (3.4-3.5) | 4.1±0.62 (3.4-4.8) |
C | 21.6 | 17.1-17.2 | 20.6-17.6 | 24.7±4.3 (19.9-28.3) | 16.4±1.1 (15.3-17.5) | 16.7±2.0 (14.5-19.5) | 17.4±1.3 (15.7-18.7) |
c' | 1.5 | 2.8-1.7 | 1.6-2.0 | 1.6±0 (1.6-1.6) | 1.9±0.21 (1.7-2.1) | 1.8±0.33 (1.4-2.3) | 1.8±0.27 (1.6-2.2) |
V% | 84.8 | 86.0-83.0 | 82.0-83.0 | 85.9±0.17 (85.7-86.0) | 85.7±0.58 (85.0-86.0) | 83.5±3.3 (77.0-88.0) | 84.3±1.5 (82-85) |
Stylet length | 19.1 | 19.6-18.8 | 18.1-18.2 | 19.2±0.2 (19.0-19.4) | 18.3±0.12 (18.2-18.4) | 17.1±0.64 (16.6-18.4) | 19.1±0.68 (18.5-20.1) |
Stylet knob width | 5.7 | 5.2-4.1 | 5.3-5.7 | 4.4±0 (4.4-4.4) | 4.9±0.9 (4.0-5.8) | 5.2±0.7 (4.3-6.3) | 5.2±0.51 (4.6-5.8) |
Stylet knob height | 3.8 | 3.1-3.0 | 3.9-3.3 | 2.9±0.57 (2.5-3.3) | 3.0±0.65 (2.3-3.6) | 3.6±0.54 (2.8-4.2) | 3.5±0.35 (3.1-3.8) |
DEGO from stylet base | 3.7 | 2.8-3.3 | 2.6-3.1 | 3.6±0.51 (3.2-4.2) | 3.8±0.64 (3.1-4.2) | 2.4±0.57 (2.0-2.8) | 2.7±0.4 (2.3-3.1) |
Anterior end to: | |||||||
centre of metacorpus | 53.5 | 72.4-62.5 | 50.8-48.2 | 56.7±4.9 (52.4-62.1) | 52.7±4.6 (49.2-57.9) | 51.0±6.1 (42.9-61.7) | 54.9±6.4 (47.6-63.1) |
median bulb base | 61.5 | 80.7-69.2 | 59.2-55.8 | 63.6±3.6 (61.2-67.8) | 61.4±4.4 (57.8-66.3) | 57.2±7.2 (46.3-69.2) | 61.1±6.9 (53.4-70) |
Cardia | 81.1 | 123-117 | 97.1-93.7 | 98.4±9.1 (92.0-105) | 94.6±12.4 (83.2-108) | 103±9.4 (96.8-110) | 101±21.6 (72.6-124) |
end of esophageal gland end | 117 | 147-134 | 125-113 | 140±28.1 (108-160) | 135±17.5 (119-154) | 139±5.1 (135-142) | 126±22.0 (103-154) |
secretory/excretory pore | 71.3 | 111-87.5 | 71.6-79.4 | 91.7±8.2 (85.4-101) | 72.4±3.1 (70.2-74.6) | 72.1±9.0 (56.9-79.8) | 85.5±4.1 (81.6-89.8) |
Esophagus overlap | 51.1 | 21.6-18.3 | 27.7-18.9 | 38.3±10.0 (31.2-45.3) | 37.8±6.3 (31.6-44.2) | 39.7±0.64 (39.2-40.1) | 29.6±8.3 (24.1-41.7) |
Max. body diam. | 30.7 | 23.6-25.8 | 27.4-24.2 | 23.4±4.7 (18.9-28.3) | 26.7±1.9 (25.3-28.8) | 28.5±3.1 (23.8-34.2) | 25.7±4.4 (22.0-30.9) |
Vulval body diam. | 24.2 | 19.0-21.4 | 22.6-20.6 | 21.7±3.8 (18.6-25.9) | 21.4±1.2 (20.2-22.5) | 22.6±2.7 (20.4-27.3) | 21.4±1.8 (19.3-23.7) |
Anal body diam. | 15.6 | 11.8-18.8 | 16.2-14.8 | 14.6±3.0 (12.4-18.0) | 15.6±0.61 (15.1-16.3) | 15.5±2.1 (11.8-18) | 16.1±1.6 (14.5-18.1) |
Anterior genital | 178-169 | 167- | – | 186±79.8 (126-277) | 124±11.1 (116-132) | 86.1±23.1 (71.8-121) | |
Spermatheca-vagina | -35.7 | 43.3- | – | 63.9±28.4 (45.9-96.6) | 37.4±9.1 (30.9-43.8) | 32±11.4 (24.6-45.2) | |
Tail length | 23.5 | 33.1-31.6 | 25.2-30.1 | 23.0±4.3 (20.2-28.0) | 29.8±4.5 (27-35) | 28.4±3.3 (24.4-32.6) | 28.9±2.4 (26-31.7) |
Number of tail annuli | 15 | 19.0-18.0 | 15.0-19.0 | 18.5±2.1 (17-20) | 18.0±2 (16.0-20.0) | 18.0±0.82 (17.0-19.0) | 17.3±1.7 (15-19) |
Vulva to anus distance | 49.7 | 57.0-57.5 | 64.4-58.7 | – | 42.5±6.0 (37.7-49.2) | 45.9±7.6 (39.4-58.9) | 51.1±3.3 (47.5-55.4) |
Post-uterine sac | 33.2 | 20.1-22.6 | 24.7-24.9 | – | 22.3±4.2 (17.6-25.7) | 21.2±4.4 (16.5-25.1) | 17.1±2.8 (13.6-19.5) |
Lateral field width | – | 11.3-11.9 | 10.7-10.3 | – | – | – | 7.4±0.51 (6.7-7.9) |
Sample | Kukuo 2 | Kukuo 3 | Wala 1 | Bagabaga 1 | Adamupe 1 | Kitoe 1 | |
N | 4♀♀ | 2♀♀ | 2♀♀ | 2♀♀ | 3♀♀* | 1♀* | |
L | 541±46.1 (501-607) | 488-541 | 516-560 | 522-516 | 549±60.1 (480-590) | 549 | |
a | 20.3±2.6 (18.7-24.2) | 20.3- | 23.5-23.7 | 18.1-19.1 | 18.9±4.6 (15.4-24.1) | 16.0 | |
b | 5.3±0.29 (4.9-5.6) | – | 5.0-4.8 | 5.1-5.3 | 4.9±1.8 (2.9-6.3) | 5.6 | |
b' | 3.8±0.29 (3.5-4.1) | – | 3.9-3.9 | 4.0-4.2 | 4.1±1.5 (2.5-5.4) | 4.1 | |
c | 17.1±2.4 (14.3-20) | 16.7-19.7 | 17.3-16.4 | 18.7-20.5 | 17.0±1.7 (15.8-19.0) | 25.1 | |
c' | 2.0±0.19 (1.7-2.1) | 1.8-1.6 | 2.5-2.3 | 1.7-1.5 | 1.9±0.36 (1.6-2.3) | 1.5 | |
V% | 84.5±1 (83.0-85.0) | 85.0-84.0 | 85.0-83.0 | 85.0-83.0 | 85.0±1.2 (84.2-86.4) | 85.7 | |
Stylet length | 18.7±0.21 (18.4-18.9) | 19.3-18.2 | 19.4-20.0 | 19.3-19.8 | 18.9±0.49 (18.3-19.2) | 19.8 | |
Stylet knob width | 5.6±0.7 (5-6.6) | 4.3-5.2 | 5.2-4.3 | 6.1-6.0 | 5.6±0.25 (5.3-5.8) | 4.9 | |
Stylet knob height | 3.6±0.22 (3.4-3.9) | 3.7-3.9 | 3.2-3.2 | 3.7-3.7 | 3.5±0.46 (3.2-4) | 3.7 | |
DEGO from stylet base | 3.1±0.25 (2.8-3.4) | – | 4.0-3.2 | 4.3-2.9 | 2.7±0.55 (2.1-3.1) | 3.0 | |
Anterior end to: | |||||||
centre of metacorpus | 58.1±4.8 (53.2-62.6) | 52.1-55.7 | 62.4-61.6 | 55.6-53.0 | 62.5±0.98 (61.4-63.3) | 61.2 | |
median bulb base | 65.9±4.8 (61.6-71.2) | 57.2-61.4 | 71.3-72.1 | 64.8-61.2 | 70.6±0.57 (70.1-71.2) | 67.3 | |
Cardia | 102±7.0 (92.5-108) | – | 104-116 | 102-96.7 | 121±37.6 (91.3-164) | 97.6 | |
end of esophageal gland end | 142±9.3 (129-150) | – | 133-144 | 130-122 | 144±42.5 (108-191) | 133 | |
secretory/excretory pore | 87.6±7.5 (78.1-96.3) | – | 99.9-89.9 | 81.0-70.6 | 90.5±10.7 (79.3-101) | ||
Esophagus overlap | 36.2±3.8 (31.1-39.5) | – | 35.9-38.4 | 39.0-29.9 | 25.3±9.4 (18.0-35.9) | 38.0 | |
Max. body diam. | 27.1±4.9 (20.7-32.4) | 24.0- | 21.9-23.6 | 28.8-27 | 29.7±4.7 (24.5-33.5) | 34.2 | |
Vulval body diam. | 21.9±2.6 (18.5-24.9) | 20.1-22.3 | 18.1-20.7 | 22.2-22.8 | 24.4±3.0 (21.0-26.4) | 20.6 | |
Anal body diam. | 16.4±1.2 (14.8-17.5) | 16.2-17.6 | 12.0-15.1 | 16.6-16.8 | 17.3±1.2 (16.4-18.6) | 14.9 | |
Anterior genital | 180±42.2 (133-234) | – | – | 219-210 | 193±90.6 (129-257) | ||
Spermatheca-vagina | 49.4±14.3 (37.9-65.4) | – | – | 38.3-42.0 | – | ||
Tail length | 31.9±3.1 (29.8-36.5) | 29.2-27.4 | 29.8-34 | 27.9-25.2 | 32.5±4.3 (29.6-37.4) | 21.9 | |
Number of tail annuli | 18.5±2.4 (16.0-21.0) | 16.0-15.0 | 18.0-16.0 | 17.0-16.0 | 21.7±3.2 (18.0-24.0) | ||
Vulva to anus distance | 52.8±6.7 (43.0-58.2) | 44.4-51.7 | 48.1-59.1 | 54.3-55.7 | 49.9±9.7 (42.8-61) | 51.5 | |
Post-uterine sac | 21.1±1.9 (19.7-23.9) | – | 18.1-19.2 | 31.5-23.9 | 18.9±1.7 (17.2-20.5) | 49.5 | |
Lateral field width | 10.2±0.71 (9.6-11.0) | – | – | 11.8-10.6 | 11.5±1.8 (10.2-12.7) |
Morphometrics derived from temporary slides; otherwise, morphometrics derived from permanent slides.
Measurements of thirteen
Sample | Igbariam 1 | Araromi 1 | Okejumu 1 | Ega 1 | Ega 2 | Ega 3 | Rimiuka 2 |
---|---|---|---|---|---|---|---|
N | 1♀ | 2♀♀ | 5♀♀ | 1♀ | 3♀♀ | 1♀ | 6♀♀ |
L | 461 | 563–584 | 493±55.9 (435–563) | 470 | 472±33.9 (445–510) | 536 | 545±30.2 (507–579) |
a | 15.7 | 22.6–19.3 | 16.6±0.72 (15.7–17.4) | 16.6 | 18.0±3.1 (15.0–21.2) | 21.0 | 19.8±1.5 (18.6–22.7) |
b | – | – | – | – | |||
b’ | 3.8 | 3.9–3.9 | 3.7±0.59 (2.9–4.2) | 3.3 | – | 5.0 | 4.2±0.22 (3.9–4.4) |
C | 21.8 | 20.1–17.3 | 19.8±4.7 (15.0–26.6) | 22.0 | 19.6±6.1 (14.3–26.3) | 21.7 | 24.1±5.6 (19.6–34.9) |
c’ | 1.5 | 1.7–1.9 | 1.5±0.34 (0.93–1.8) | 1.6 | 1.9±0.47 (1.5–2.4) | 1.7 | 1.6±0.21 (1.2–1.8) |
V% | 85.0 | 87.0–85.0 | 85.6±1.1 (84.0–87.0) | 85.0 | 84.7±0.58 (84–85) | 86.0 | 84.7±1.2 (83–86) |
Stylet length | 17.1 | 20.4–20.4 | 18.9±0.63 (18.0–19.6) | 19.4 | 19.3±0.64 (18.6–19.7) | 19.1 | 18.6±0.44 (18.1–19.1) |
Stylet knob width | 4.2 | 5.8–5.8 | 5.0±0.78 (3.8–5.9) | 4.7 | 4.9±0.51 (4.3–5.3) | 5.2±0.54 (4.4–5.8) | |
Stylet knob height | 3.4 | 3.8–4.0 | 3.1±0.51 (2.5–3.7) | 2.9 | 3.1±0.0 (3.1–3.1) | 3.3±0.21 (3.1–3.6) | |
DEGO from stylet base | 2.8–2.9 | 2.9±0.24 (2.6–3.1) | 3.3 | – | 2.7±0.99 (2–3.4) | ||
|
|||||||
centre of metacorpus | 52.4 | 61.5–64.2 | 61.9±11.1 (47.3–74.1) | 58.0 | 52.2±3.6 (48.4–55.6) | 54.6 | 58.8±7.3 (51.2–69.3) |
median bulb base | 58.2 | 71.3–72.7 | 69.9±10.6 (56.7–81.8) | 66.8 | 59.1±3.6 (55.6–62.8) | 62.0 | 66.4±6.7 (58–75.6) |
cardia | – | – | – | – | |||
end of esophageal gland end | 120 | 146–151 | 135±18.4 (110–150) | 144 | – | 107 | 132±8.6 (123–143) |
secretory/excretory pore | 63.9 | 97.0–98.1 | 89.3±12.1 (77.3–110) | 87.5 | 79.6±5.9 (75.4–83.8) | 81.3 | 90.6±10.0 (84.1–111) |
Esophagus overlap | 21.1 | 35.5–38.6 | 36.4±4.8 (32.9–43.2) | 31.1 | – | 21.8 | 28.9±4.3 (23–32.9) |
Max. body diam. | 29.3 | 24.9–30.2 | 28.7±1.6 (27.4–30.9) | 28.3 | 26.6±4.3 (21.7–29.6) | 25.5 | 27.7±1.5 (25.5–29.2) |
Vulval body diam. | 21.5 | 22.1–24.1 | 23.4±1.5 (21–24.7) | 21.3 | 20.8±3.7 (16.6–23.5) | 20.6 | 22.9±1.2 (21.3–24.6) |
Anal body diam. | 13.7 | 16.6–17.8 | 18.0±2.9 (15.6–22.8) | 13.5 | 13.6±2.5 (11.3–16.3) | 14.8 | 14.7±0.9 (13.4–15.8) |
Anterior genital | – | – | – | – | |||
Spermatheca-vagina | – | – | – | – | |||
Tail length | 21.1 | 28.0–33.8 | 25.6±4.3 (21.2–32.2) | 21.3 | 25.8±7.9 (16.9–32.2) | 24.7 | 23.4±3.7 (16.1–25.9) |
Number of tail annuli | – | – | – | – | |||
Vulva to anus distance | 42.7 | 47.0–53.8 | 44.3±6.5 (39.2–53.5) | 49.2 | 48.8±9.8 (37.6–55.9) | 47.4 | 59.1±8.6 (49.0–72.7) |
Post-uterine sac | 20.9–20.2 | 18.0±1.6 (16.4–19.9) | 19.9 | – | 16.6±2.8 (14.6–18.6) | ||
Lateral field width | – | – | – | – | |||
Sample | Eggon 1 | Umudike 1 | Umudike 2 | Amoka 1 | Rimiuka 1 | Mbaise 1 | |
N | 4♀♀* | 4♀♀ | 1♀ | 2♀♀ | 7♀♀ | 21♀♀ | 14♀♀ |
L | 568 ± 57 (515–648) | 578±56.1 (519–648) | 486 | 551–599 | 591±42.5 (556–679) | 509±84.1 (394–641) | 569±31.4 (510–613) |
a | 20.7±3.8 (18.6–26.3) | 18.7±1.4 (17.4–20.6) | 15.6 | 23.4–24.0 | 21.7±2.5 (18.3–24.7) | 20.3±2.9 (16.0–24.8) | 22.6±2.8 (17.0–27.0) |
b | – | – | 3.0 | 4.7–4.8 | 5.0±0.6 (4.3–5.8) | – | 7.5±0.93 (6.3–8.8) |
b’ | – | 4.8±0.57 (4.1–5.5) | 2.5 | 4.4–4.3 | 4.0±0.48 (3.3–4.5) | 3.5±0.52 (2.7–4.5) | 4.4±0.59 (3.6–5.5) |
C | 25.1±9.3 (19.5–39) | 23.6±2.2 (21.3–25.5) | 16.4 | 26.2–20.6 | 20.4±6.3 (15.8–34.1) | 18.7±3.0 (13.4–24.4) | 19.8±1.6 (17.9–23.2) |
c’ | 1.6±0.33 (1.2–2.0) | 1.5±0.13 (1.3–1.6) | 1.8 | 1.3–1.8 | 1.9±0.21 (1.6–2.3) | 1.7±0.18 (1.5–2.1) | 2.0±0.37 (1.5–2.5) |
V% | 85.5±0.58 (85.0–86.0) | 85.0±0.82 (84.0–86.0) | 83.6 | 86.0–84.0 | 85.6±0.53 (85.0–86.0) | 84.9±1.7 (81.0–87.0) | 84.6±1 (82–86) |
Stylet length | 17.8±1.0 (16.3–18.4) | 18.8±0.57 (18.3–19.6) | 19.1 | 20.5–18.5 | 19.1±0.6 (18.3–20.1) | 19.4±1.0 (17.2–20.9) | 18.9±0.69 (17.8–19.8) |
Stylet knob width | 5.3±0.49 (4.7–5.6) | 4.8±0.46 (4.1–5.1) | 5.6 | 5.1–5.5 | 5.6±0.28 (5.0–5.8) | 5.0±0.46 (4.1–6.0) | 5.1±0.52 (4.3–5.7) |
Stylet knob height | 3.4±0.21 (3.2–3.6) | 3.6±0.18 (3.4–3.8) | 4.0 | 3.4–3.4 | 3.9±0.45 (3.2–4.5) | 3.0±0.52 (2.0–3.7) | 3.5±0.46 (2.8–4.6) |
DEGO from stylet base | 3.6±0.49 (3.2–3.9) | 3.0±0.45 (2.6–3.6) | 2.1 | 2.4–3.3 | 3.2±0.56 (2.4–3.9) | 3.2±0.51 (2.4–4.2) | 3.0±0.47 (2.3–3.7) |
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centre of metacorpus | 58.0±7.1 (50.6–67.0) | 59.4±5.3 (55.7–67) | 63.3 | 58.9–61.3 | 62.9±1.5 (60.0–65.2) | 64.0±4.7 (54–72.6) | 61.7±5.1 (55.5–72.9) |
median bulb base | 66.0±8.0 (57.4–76.5) | 67.8±5.9 (63.2–75.9) | 71.2 | 66.2–69.0 | 70.7±1.7 (68.7–73.8) | 72.4±4.2 (62.2–78.4) | 70.5±4.7 (65.1–81.3) |
Cardia | – | – | 164 | 118–125 | 120±9.5 (104–131) | – | 78.2±9.1 (68.9–91.3) |
end of esophageal gland end | – | 122±4.7 (117–127) | 191 | 127–139 | 149±11.4 (134–167) | 148±17.1 (113–181) | 130±15.3 (103–149) |
secretory/excretory pore | 102±3.5 (98.8–106) | 84.4±13.7 (74.2–100) | 91.5 | 87.1–98.9 | 96.4±5.5 (89.3–102) | 96.9±10.3 (82.8–128) | 93.6±11.6 (76.5–114) |
Esophagus overlap | 29.2±1.9 (27.8–30.5) | 27.5±2.5 (24.1–29.5) | 35.9 | 40.9–18.8 | 26.8±7.8 (17.6–39.6) | 37.9±9.5 (12.6–50.6) | 30.0±8.7 (14.6–45.9) |
Max. body diam. | 27.8±2.5 (24.6–30.1) | 31.0±2.5 (28.3–34.2) | 31.1 | 23.5–24.9 | 27.5±2.6 (24.5–31.2) | 25.3±3.5 (21.6–33.4) | 25.7±4.3 (21.8–34.2) |
Vulval body diam. | 23.4±1.6 (21.4–25.2) | 24.2±1.6 (22.4–26) | 25.9 | 20.2–19.4 | 23.1±2.3 (20.3–26.3) | 22.1±2.8 (17.4–28.0) | 20.7±3.5 (16.6–28.2) |
Anal body diam. | 15.9±3.4 (11.4–18.6) | 16.7±1.2 (15.8–18.4) | 16.9 | 16.0–16.6 | 16.0±3.2 (10.0–19.5) | 16.0±1.8 (12.6–18.7) | 14.8±2.6 (11.2–19.3) |
Anterior genital | – | – | 129 | 141–198 | 166±66.1 (84.3–243) | – | 206±43.6 (162–261) |
Spermatheca-vagina | – | – | 24.2 | 37.5–39.4 | 37.5±16.2 (20.1–55.0) | – | 51.1±25.7 (17.1–77.6) |
Tail length | 24.7±7.7 (13.2–29.7) | 24.5±2.2 (21.6–26.7) | 29.6 | 21.0–29.1 | 30.6±6.9 (17.7–37.4) | 27.3±2.2 (23.1–32) | 28.8±2.5 (25–32.1) |
Number of tail annuli | – | – | 18.0 | 16.0– | 21.9±1.5 (20.0–24.0) | – | 23.8±2.2 (21–27) |
Vulva to anus distance | 60.0±7.8 (50.3–66.9) | 57.7±8.8 (51.2–70.7) | 45.9 | 60.9–65.7 | 52.9±11.4 (42.8–73.2) | 48.5±9.1 (25.9–62.9) | 58.9±3.7 (54.2–66.7) |
Post-uterine sac | – | 19.5±2.9 (16.2–21.5) | 19.1 | 12.3–14.2 | 19.9±3.0 (17.2–25.1) | 18.9±4.7 (14.3–34.9) | 19.8±1.8 (16.1–22.8) |
Lateral field width | – | – | 12.7 | 8.4–7.7 | 9.4±1.6 (7–10.8) | – | 7.3±1.1 (6.1–8.1) |
Morphometrics derived from temporary slides; otherwise, morphometrics derived from permanent slides. All measurements are in μm and in the form: mean±s.d. (range)
Morphological variations in
Body small 390–679 μm long, stout to moderately slender. Habitus almost straight when heat-relaxed. Lateral fields usually with four longitudinal lines; sometimes 4 to 6 lateral lines at mid body or 2 additional lateral fields faint or broken. Cephalic region slightly offset from body, with two lip annuli. Robust stylet (16.3–20.9 μm long) with stout and rounded basal knobs, 3.8–6.6 μm wide, with irregular shape on the surface. The dorsal esophageal gland opening (DEGO) at 2.0–4.3 μm posterior the stylet base. Median bulb muscular, rounded to oval. Excretory pore just anterior to region of esophago-intestinal junction, but often indistinct. Esophageal glands overlapping intestine ventrally and sometimes laterally. Reproductive system monodelphic-prodelphic, ovary with oocytes in one row, occasionally two rows. Spermatheca usually indistinct, if present, well developed, rounded to spherical, filled with sperm cells in a few specimens. Vulva at 77–88% of body length. Post-vulval uterine sac generally shorter than body diameter length (12.3–34.9 μm long). Vulva-anus distance about twice the tail length. Tail slightly tapering, terminus mostly bluntly rounded, varying from somewhat narrower, flat to slightly indented; terminus smooth.
From the morphology and the morphometrics, the studied populations are in agreement with the original description of
Measurements of a
Sample | Otukpo 1 | |
---|---|---|
n | 5♀♀* | 7♀♀ |
L | 503±99 (367–625) | 427±34.7 (382–492) |
a | 18.4±3.1 (16.4–22) | 22.4±1.4 (20.8–24.6) |
b | – | 6.1±0.52 (5.6–7) |
b’ | – | 4.4±0.71 (3.8–5.6) |
c | 15.9±3.5 (13.5–19.9) | 12.8±1.9 (10.8–15.7) |
c’ | 2.4±0.31 (2.1–2.7) | 2.6±0.42 (2.2–3.4) |
V% | 75.7±1.6 (74.1–78) | 74.9±1.8 (72.6–78) |
Stylet length | 13.9±0.43 (13.6–14.5) | 14.9±1.6 (11.8–16.1) |
Stylet knob width | 4.3±0.27 (3.9–4.5) | 2.1±0.19 (2.0–2.4) |
Stylet knob height | 2.6±0.28 (2.3–2.9) | 2.4±0.21 (2.2–2.6) |
DEGO from stylet base | 3.3±0.34 (2.8–3.6) | 4.4±0.87 (3.8–5.4) |
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centre of metacorpus | 50.0±4.1 (46.8–57.0) | 45.5±5.8 (36.0–50.7) |
median bulb base | 57.4±3.6 (54.4–63.5) | 54.3±4.3 (48.5–58.8) |
cardia | – | 70.6±7.5 (59.2–81.1) |
end of esophageal gland end | – | 101±17.2 (74.4–124) |
secretory/excretory pore | – | 54.7±3.9 (50.0–59.2) |
Esophagus overlap | – | – |
Max. body diam. | 24.3±2.2 (22.3–26.6) | 19.2±1.7 (17.4–22.4) |
Vulval body diam. | – | 20.9±4.8 (17.4–30.3) |
Anal body diam. | 14.6±0.51 (14–15.2) | 13.1±1.8 (11.0–15.2) |
Anterior genital | – | 93.7±17.5 (81.3–106) |
Spermatheca-vagina | – | – |
Tail length | 36.1±4.1 (31.4–39.0) | 34.0±4.7 (28.8–39.7) |
Number of tail annuli | – | 24.0±2.8 (22.0–26.0) |
Vulva to anus distance | – | – |
Post-uterine sac | – | – |
Lateral field width | – | 7.0±0.28 (6.8–7.2) |
Morphometrics derived from temporary slides; otherwise, morphometrics derived from permanent slides. All measurements are in μm and in the form: mean ± s.d. (range).
Light micrographs of female
Female:
Body small, 367–625 μm long, stout to moderately slender. Habitus slightly straight when heat-relaxed. Lateral fields indistinct; when observed, with four to six longitudinal lines at mid body. Lateral field 6.8–7.2 μm wide at mid body with crenated margins (Figure 4). Short stylet 15 µm (11.8–16.1 μm), with rounded knobs. Median bulb oval. Cephalic region slightly offset from body, with two annuli. Esophageal glands overlapping intestine ventrally and laterally. Spermatheca rounded and obscure. Vulva located at 72.6–78%. Tail slightly tapering, terminus mostly broadly rounded.
The studied population was in agreement with the original description of
Measurements of two
Sample | Umuagu 1 | Kintampo S 1 | |
---|---|---|---|
n | 1♀ | 2♀♀* | 4♀♀ |
L | 382 | 381–561 | 433±36.9 (403–483) |
a | 23.1 | 17.5–17.4 | 19.9±2.7 (17.1–23.5) |
b | – | 4.5±0.36 (4.0–4.8) | |
b’ | – | 4.5±1.3 (3.2–6.3) | |
c | 28.7 | 15.6–21.7 | 17.6±2.1 (14.7–19.7) |
c’ | 1.8 | 1.8–1.7 | 2.0±0.24 (1.6–2.1) |
V% | 70.3 | 70.0–70.8 | 71.8±1.1 (70.7–73.2) |
Stylet length | 15.7 | 14.6–14.7 | 15.9±0.95 (14.6–16.9) |
Stylet knob width | 4.9–4.7 | 4.1±0.4 (3.7–4.4) | |
Stylet knob height | 2.9–3.3 | 2.4±0.29 (2.1–2.7) | |
DEGO from stylet base | 3.5 | – | 2.9±0.21 (2.6–3.1) |
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centre of metacorpus | 44.1 | 47.4– | 50.3±3.1 (47.3–53.7) |
median bulb base | 55.9– | 57.6±3.3 (53.9–60.7) | |
cardia | – | 95.7±8.3 (84.2–103) | |
end of esophageal gland end | 116 | – | 101±24.1 (69.6–126) |
secretory/excretory pore | 69.1 | 72.0– | 71.1±7.9 (64.8–82.6) |
Esophagus overlap | 21.4–23.9 | 22.3±4.3 (17.1–26.5) | |
Max. body diam. | 16.5 | 21.8–32.3 | 21.9±1.4 (20.5–23.8) |
Vulval body diam. | 15.3 | 20.8–24.2 | 19.6±1.2 (18.3–20.7) |
Anal body diam. | 7.2 | 13.3–15.0 | 12.9±0.89 (12.0–14.1) |
Anterior genital | – | 159±27.5 (121–183) | |
Spermatheca-vagina | – | 36.3±3.5 (31.6–40.2) | |
Tail length | 13.3 | 24.5–25.9 | 24.8±3.2 (20.4–27.7) |
Number of tail annuli | – | 19.3±1.5 (18.0–21.0) | |
Vulva to anus distance | 110 | 93.2–149 | 94.2±7.4 (85.6–103) |
Post-uterine sac | 25.8 | 19.6–30.4 | 21.5±5.3 (15.3–26.5) |
Lateral field width | – | 7.9±1.2 (6.5–9.3) |
Morphometrics derived from temporary slides; otherwise, morphometrics derived from permanent slides. All measurements are in μm and in the form: mean ± s.d. (range).
Light micrographs of female
Female:
Body slender, short 381–561 μm long, and near-straight when heat-relaxed. Cephalic region continuous with body and bearing three annuli. Lateral fields with four lines at mid body. Stylet 14.6–16.9 µm long, with broad, anteriorly flattened basal knobs. Esophageal glands overlapping intestine ventrally and laterally. Ovary usually long. DEGO at 3 μm posterior to the stylet base. Excretory pore just anterior to the esophago-intestinal junction. Spermatheca rounded, without sperm. Vulva at 70–73.2%. Post-vulval uterine sac short, about 1 body diam. long. Tail tapering, with 18–21 annuli terminating in an almost pointed tip.
Males: Not observed.
Remarks: Based on the morphology and the morphometrics, the studied populations were in agreement with the original description of
The D2-D3 alignment included 80
Bayesian 50% majority rule consensus tree from four runs as inferred from analysis of the D2-D3 of 28 S rRNA gene sequence alignment under the GTR + I + G model. (-lnL = 11091.5259; AIC = 22563.051780; freqA = 0.1873; freqC = 0.2354; freqG = 0.3250; freqT = 0.2523; R(a) = 1.0893; R(b) = 3.9431; R(c) = 2.1703; R(d) = 0.4799; R(e) = 5.3436; R(f) = 1.0000; p-inv = 0.3210; gamma shape = 0.8480). Posterior probability values exceeding 50% are given on appropriate clades). New sequences are indicated by bold font.
The sequences of
Sequences of
The
Bayesian 50% majority rule consensus tree from four runs as inferred from analysis of the
Sequences of
Sequences of
Prior to the current study, seven RLN species, i.e.
Traditional taxonomy can have serious limitations for differentiating species of
In this study,
The observed morphology and morphometrics of
Although the D2-D3 sequences of
Augmenting the problem to delimitate both species, the COI sequences
In summary,
Evidently, additional morphological and molecular characterizations are required to further analyses the species group of