Characterization of Hoplolaimus seinhorsti and Hoplolaimus pararobustus (Tylenchina: Hoplolaimidae) from banana, with phylogeny and species delineation in the genus Hoplolaimus

Olajide, Emmanuel; Singh, Phougeishangbam Rolish; Kolombia, Yao A.; Rumbarar, Merlin Kornelia; Couvreur, Marjolein; Bert, Wim

Characterization of Hoplolaimus seinhorsti and Hoplolaimus pararobustus (Tylenchina: Hoplolaimidae) from banana, with phylogeny and species delineation in the genus Hoplolaimus

Volume 55 (2023): Issue 1 (February 2023)

By:

Emmanuel Olajide, Phougeishangbam Rolish Singh, Yao A. Kolombia, Merlin Kornelia Rumbarar, Marjolein Couvreur and Wim Bert

Open Access

|May 2023

Figures & Tables

Light microscopy images of females of H. seinhorsti (A) whole bodies; (B-G) anterior body in lateral view showing SE pore opening and hemizonid (indicated by arrows), stylet and stylet knobs. DGO and median bulb; (H-K) esophageal region showing five gland nuclei (pointed by arrows); (L,M) scutella, lateral view; (N,O) vulva region in lateral view; (P) lateral incisures around mid-body; (Q-T) tail region showing anal opening, tail annuli number and lateral incisure.

Scanning electron microscopy images of females of H. seinhorsti (A) whole body; (B-D) head region; (E,F) vulva region in ventral and lateral views; (G) scutellum anterior to vulva in lateral view; (H) scutellum posterior to vulva along with lateral incisures around the posterior region; (I-K) tails in lateral view showing anal openings.

Light microscopy images of females and males of H. pararobustus (A) whole body of female and male; (B-D) anterior body in lateral view showing SE-pore opening, stylet and stylet knobs. DGO and median bulb; (E) vulva region with no epiptygma in lateral view; (F) oocytes and ovary with sperm; (G) lateral incisures around mid-body; (H) scutella, lateral view; (I-M) female and male tail region showing anal opening, tail annuli number and lateral incisure.

BI phylogenetic tree inferred from analysis of the D2-D3 expansion segment of 28S rDNA sequences from nine known and three unknown Hoplolaimus species using the GTR + I + G model. Bayesian posterior probabilities are given next to each node and H. seinhorsti and H. pararobustus is presented in bold. Intraspecific variation of a clade indicated by a bar is given to the right of the gray bars, nucleotide differences between sister clades is provided left to the gray bars. Red and blue bars represent species boundaries estimated by GMYC and bPTP methods, respectively. A star indicates data with too many non-nucleotide characters in the sequences.

BI phylogenetic tree inferred from analysis of COI mtDNA sequences from seven known and one unknown Hoplolaimus species using GTR + I + G model. Bayesian posterior probabilities are given next to each node, H. seinhorsti and H. pararobustus are given in bold. Intraspecific variation of a clade indicated by a bar is given to the right of the gray bars, nucleotide differences between sister clades is provided left to the gray bars. Red and blue bars represent species boundaries estimated by GMYC and bPTP methods, respectively.

BI phylogenetic tree inferred from analysis of ITS rDNA sequences from seven known and four unknown Hoplolaimus species using the GTR + I + G model. Bayesian posterior probabilities are given next to each node and H. seinhorsti is provided in bold. Intraspecific variation of a clade indicated by a bar is given to the right of the gray bars, nucleotide differences between sister clades is provided left to the gray bars. Red and blue bars represent species boundaries estimated by GMYC and bPTP methods, respectively.

BI phylogenetic tree inferred from analysis of 18S rDNA sequences from three known and two unknown Hoplolaimus species using GTR + I + G model. Bayesian posterior probabilities are given next to each node and H. pararobustus is given in bold. Intraspecific variation of a clade indicated by a bar is given to the right of the gray bars, nucleotide differences between sister clades is provided left to the gray bars. Red and blue bars represent species boundaries estimated by GMYC and bPTP methods, respectively.

Comparison of 37 Hoplolaimus species after Handoo and Golden (1992) and Ghaderi et al_ (2020)_ The comparison includes eleven morphological and morphometric data and the presence or absence of male_ Species included in this study are highlighted in bold and the measurements of body length (mm), stylet length and spicule length are in μm in range_

	Length	Lateral incisures	Gland nuclei	Stylet length	Labial annules	Longitudinal striae on basal lip annules	EP in relation to hemizonid	Intestinal post-rectal sac	Phasmids in relation to vulva	Tail annules	Males	Spicule length
H. abelmoschi	1.5-1.8	2	3	42-47	5	25-28	Anterior	Present	Both adjacent, one anterior & one posterior	9-15	Present	44-47
H. aegypti	1.3-1.9	1	5-6	45-50	4	13-22	Anterior	Present	One anterior & one posterior	17-27	Present	54-65
H. aorolaimoides	0.8-0.9	4	3	31-35	4-5	6-13	Posterior	Present	One anterior & one posterior	6-17	Present	31-37
H. bachlongviensis	1.2-1.5	1	6	44-50	4.0	6	Anterior	Absent	One anterior & one posterior	9-13	Unknown	-
H. californicus	1.1-1.7	4	3	46-53	6	36	Posterior	Present	Both posterior	14	Present	45-55
H. capensis	1.6-2.1	2	3	46-58	5-6	Unknown	Anterior	Present	One anterior & one posterior	9-16	Present	51-70
H. casparus	1.2	0	3	39.7	3	Unknown	Anterior	Absent	One anterior & one posterior	12	Present	39-40
H. caudifurcatus	1.0-1.1	-	>4	52-55	4-5	Unknown	Anterior	Unknown	Unknown	15-20	Unknown	-
H. cephalus	1.2	0	6	34	Smooth	0	Anterior	Absent	One anterior & one posterior	6	Present	33-38
H. chambus	1.2-1.6	Breaks	6	41-45	3	6	Anterior	Present	One anterior & one posterior	9-13	Unknown	-
H. citri	0.8-1.3	0	6	35-37	4	10-12	Anterior	Absent	One anterior & one posterior	12-15	Present	38-47
H. clarissimus	1.4-1.8	4	6	46-53	4	18-31	Posterior	Present	One anterior & one posterior	20-26	Present	55-61
H. columbus	1.3-1.8	1	6	40-48	3	10-15	Anterior	Present	One anterior & one posterior	16-22	Rare	37-53
H. concaudajuvencus	1.1-2.0	4	3	50-57	5-6	36	Posterior	Absent	One anterior & one posterior	7-14	Present	45-56
H. diadematus	1.1-1.8	2	3	47-52	3-4	20	Anterior	Unknown	One anterior & one posterior	9-13	Present	48-53
H. dimorphicus	1.1-1.6	0	6	34-36	2-3	18-21	Anterior	Absent	One anterior & one posterior	6-10	Present	36-41
H. dubius	1.1-1.3	1	6	31-42	3	14	Anterior	Absent	One anterior & one posterior	10-15	Present	37-44
H. galeatus	1.2-1.9	4	3	43-52	5	32-36	Posterior	Present	One anterior & one posterior	10-16	Present	40-52
H. igualaensis	1.1-1.5	4	3	40-50	5-6	Unknown	Posterior	Unknown	Both posterior	10-15	Present	36-43
H. imphalensis	1.0-1.4	1	3	34-37	3-4	29-30	Anterior	Present	One anterior & one posterior	12-14	Present	37-45
H. indicus	1.0-1.6	1	6	33-47	3-4	6-20	Anterior	Present	One anterior & one posterior	8-22	Present	34-42
H. intermedius	1.0-1.3	Breaks	3	37-40	4-5	6	Anterior	Unknown	One anterior & one posterior	-	Present	43-47
H. jalalabadiensis	1.2-1.7	Breaks	6	37-44	3-4	24-25	Anterior	Present	One anterior & one posterior	16-22	Unknown	-
H. johani	1.0-1.4	Not visible	3-6	21-30	3-5	Unknown	Anterior	Unknown	Unknown	14	Present	28-43
H. maggentii	1.0-1.4	Absent	3-5	43-48	3-5	Unknown	Anterior	Unknown	Unknown	8-17	Unknown	-
H. magnistylus	1.4-2.0	4	3	52-61	4-6	22-34	Posterior	Absent	One anterior & one posterior	12-17	Present	52-58
H. pararobustus	1.2-1.6	Breaks	3	41-44	4-5	-	Anterior	Present	One anterior & one posterior	9-15	Present	40-44
H. pararobustus	1.0-1.6	2-3	3	38-49	4-5	18-25	Anterior	Present	One anterior & one posterior	7-15	Present	40-57
H. puertoricensis	1.3-1.7	0	5	41-45	3	6-9	Anterior	Absent	Both anterior	19	Unknown	-
H. puriensis	1.1-1.3	4	4	33-37	4-5	Unknown	Anterior	Absent	One anterior & one posterior	12-13	Present	31
H. smokyensis	0.9-1.8	4	3	41-51	5-6	24	Posterior	-	One anterior & one posterior	-	Present	37-47
H. sacchari	1.1-1.2	4	6	34-35	3	8	Anterior	Present	One anterior & one posterior	9-10	Present	39-40
H. seinhorsti	1.3-1.7	1	5	38-44	4-5	Unknown	Anterior	Absent	One anterior & one posterior	13-16	Unknown	-
H. seinhorsti	1.1-1.6	1	6	40-49	4	8-12	Anterior	Absent	One anterior & one posterior	10-15	Unknown	-
H. seshadrii	1.5-1.8	0	6	42-43	3	20-22	Anterior	Present	One anterior & one posterior	14-18	Unknown	-
H. singhi	1.4-2.1	0	3	43-56	4	Unknown	Anterior	Absent	One anterior & one posterior	7	Present	52
H. stephanus	1.0-1.5	4	3	43-50	4	24-28	Posterior	Present	One anterior & one posterior	12	Present	30-38
H. tabacum	1.3-1.4	1	6	43-45	3-4	Unknown	Anterior	Present	Both posterior	12-15	Unknown	-
H. tylenchiformis	0.9-1.4	4	3	42-51	3-4	20-24	Posterior	Present	One anterior & one posterior	8-14	Present	31-38

Number of species according to the two species-delimitation methods (GMYC vs bPTP)_

Gene region	Number of species
Gene region	Morphospecies (unidentified species included)	GMYC	bPTP
D2-D3 of 28S rRNA	10	27	9
COI mtDNA	8	13	13
ITS rRNA	7	16	7
18S rRNA	4	6	5

Morphometric data of Hoplolaimus seinhorsti and Hoplolaimus pararobustus_ All measurements are in μm (except for ratio) and in the form: mean ± sd (range)_ Species included in this study are presented in the first two columns of the table_

Character	Hoplolaimus seinhorsti (Indonesian specimen)	Hoplolaimus pararobustus (Nigerian specimens)		Hoplolaimus pararobustus (Namibian specimens according to Marais et al., 2020)		Hoplolaimus pararobustus (Syntypes; according to Sher, 1963)
	15♀♀	16♀♀	10♂♂	21♀♀	21♂♂	3♀♀	5♂♂
L	1521±143(1280-1700)	1322±107(1161-1552)	1233±50.7 (1171-1325)	1100±76.1 (957-1245)	925±65 (818-1018)	1420-1520	1090-1250
a	26.2±1.3(22.7-28.3)	29.8±2.9(24.7-36)	33.8±1.6 (31.1-36.4)	29±3.5 (23.7-36)	29.2±4.2 (22-38.3)	23-25	21-26
b	10.4±0.8(7.0-11.4)	9.5±0.9(8-11.4)	10.1±0.5 (9.2-10.7)	7.4±0.7 (6.2-8.6)	6.7±0.4 (6-7.5)	8.8	7-7.4
c	53.7±5.7(38.1-62.3)	62.2±11.3(42.6-88.2)	39±1.6 (37-41.6)	59.7±10.5 (46.9-80.6)	34.7±4.3 (25-41)	42-47	28-42
c’	0.8±0.7(0.7-0.9)	0.7±0.1(0.5-0.9)	1.49±0.04 (1.4-1.5)	0.8±0.1 (0.6-1.1)	1.5±0.2 (1.3-2)	-	-
DGO	5.3±0.5(4.6-6.4)	6.6±2.1(3.7-9.6)	6.2±1.2 (4.5-8.1)	5±0.7 (3-6)	4±0.9 (3-6)	-	-
V	55.2±2.6(50.2-59.3)	59.4±3.5(54-70.1)	-	55±2.5 (49-67)	-	57-62	-
Stylet length	42.1±1.7(38.3-44.1)	42.5±0.8(41.3-43.8)	42.4±1.1 (41.2-44.3)	36±1.6 (34-40)	34±1.3 (32-38)	46-49	44-46
Stylet cone length	20.8±1.2(18.2-23.2)	21.7±1.1(20.2-23.7)	21.3±1.6 (19-23.3)	-	-	-	-
Stylet knob length	7.7±0.4(6.0-7.9)	7.8±1.1(5.7-9.1)	5.3±0.7 (4.5-6.3)	6±0.5 (5-7)	5±0.6 (4-6)	-	-
Excretory pore from anterior	151 ±7.91(140-167)	110±11.8(85.4-128)	89.2±7.1 (78.3-98.8)	108±11.9 (82-123)	93±13.6 (74-121)	-	-
Nerve ring from anterior	118±4.9 (111-126)	81.1±7.9(70.8-94.8)	79.8±7.1 (71.6-94.8)	-	-	-	-
Pharynx	-	140±10.7(114-156)	I23±3.3 (120-129)	-	-	-	-
Pharyngeal gland end from anterior	200±15.7(162-216)	170±16.3(143-201)	139±8.1 (131-158)	-	-	-	-
Anterior phasmid of body length (%)	36.1±2.2(33-38.9)	-	-	-	-	27-30	25-35
Posterior phasmid of body length (%)	81.1±0.9(80-82)	-	-	-	-	74-79	77-84
Vulva from anterior end	816±72.4(715-912)	784±61.3(664-908)	-	-	-	-	-
Diameter at mid-body	58.3±6.1(44.3-66.6)	44.5±2.6(39.3-49.9)	36.5±0.8 (35.3-37.6)	39±4 (32-46)	32±2.9 (27-38)	-	-
Anal body diameter	33.8±2.9(30.1-38.5)	320±2.1(28.2-37.1)	21.3±0.7 (20.2-22.4)	25±2.2 (21-29)	17±1.3 (15-20)	-	-
Lip region height	9.4±0.7(8.1-10.4)	7.8±1.2(6.0-9.7)	8.2±0.5 (7.5-9)	7±0.5 (6-8)	6±0.6 (5-7)	-	-
Lip region diameter	I6.3±0.9(15.0-18.0)	15.4±1.1(13.4-17.6)	11.9±1.0 (10-12.9)	13±1 (12-15)	12±0.9 (11-13)	-	-
Lip annulus	-	4.2±0.4 (4-5)	4.1±0.3 (4-5)	-	-	-	-
Tail annuli	13-16	-	-	-	-	-	-
Tail length	28.4±3.1(23.7-34.9)	21.9±4(15.7-30.4)	31.6±1.0 (30-32.7)	19±3.1 (15-24)	27±3.5 (22-35)	-	-
Spicule length	-	-	41.4±1.3 (44.7-48.5)	-	38±2.3 (35-42)	-	52-57
Gubernaculum	-	-	21.8±0.7 (19.2-21.8)	-	17±2.3 (11-20)	-	22-26

List of unlabeled, mislabeled Hoplolaimus sequences on GenBank reassigned to corrected species in this study_

			Accession number
No	Species name on GenBank	28S	COI	ITS	18S	Remarks	Reassigned Species name/ Decision
1	Hoplolaimus sp.	KY639326	KY639374			Kolombia et al. (2017) provided these sequences as an outgroup, and thus lacking morphological data. The sequence form a maximally supported clade with H. pararobustus based on 28S D2-D3 rRNA, the bPTP output also confirmed that this sequence belongs to H. pararobustus.	H. pararobustus
2	Hoplolaimus sp.	EU586798EU586797EU626794EU626795				Bae et al. (2008) provided these sequences. These sequences forms a maximally supported clade with H. stephanus, the bPTP output also confirms that these sequences belong to a single species.	H. stephanus
3	Hoplolaimus sp.				OM218727OM218726OM218725	Phylogenetic results and both species delimitation results (bPTP and GMYC) indicate that these sequences and H. columbus (KJ934150, KJ934149) sequences belong to a single species.	H. columbus
4	Hoplolaimus sp.		KP230658KP230659	KP303683KP303684		The sequences were originally provided by Holguin et al. (2015), and subsequently associated to the original description of H. smokyensis by Ma et al. (2019).	H. smokyensis
5	Hoplolaimus galeatus	KY849910				This sequence is available on GenBank without morphological data. It forms a maximally supported clade with H. magnistylus (MF767410, Donald et al., 2013; EU626789, EU626790, Bae et al., 2008). Assuming that the sequences of H. galeatus EU626784, EU626786, HQ678710, HQ678711 are genuine. H. galeatus (KY849910) must be incorrectly assigned.	H. magnistylus
6	Hoplolaimus concaudajuvencus			KP303685KP303686		Holguin et al. (2015) provided these two sequences as unknown Hoplolaimus species in their paper although they were deposited on GenBank as H. concaudajuvencus. However, The sequences form a maximally supported clade with H. magnistylus (KP303623, KP303634, KP303681, KP303682, EU515325, EU515326, Bae et al., 2008; Holguin et al., 2015), also confirmed by bPTP and GMYC species delimitation.	H. magnistylus
7	Hoplolaimus stephanus			KP303639		Holguin et al. (2015) provided this sequence as H. columbus in their paper, but deposited the sequence on GenBank as H. stephanus. This sequence forms a maximally supported clade with other H. columbus sequences.	H. columbus

DOI: https://doi.org/10.2478/jofnem-2023-0019 | Journal eISSN: 2640-396X | Journal ISSN: 0022-300X

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Language: English

Submitted on: Nov 19, 2022

Published on: May 23, 2023

Published by: Society of Nematologists, Inc.

In partnership with: Paradigm Publishing Services

Publication frequency: 1 issue per year

Keywords:

Banana,

Plant-parasitic nematode,

Scanning electron microscopy,

Related subjects:

© 2023 Emmanuel Olajide, Phougeishangbam Rolish Singh, Yao A. Kolombia, Merlin Kornelia Rumbarar, Marjolein Couvreur, Wim Bert, published by Society of Nematologists, Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.

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Characterization of Hoplolaimus seinhorsti and Hoplolaimus pararobustus (Tylenchina: Hoplolaimidae) from banana, with phylogeny and species delineation in the genus Hoplolaimus

Figures & Tables

Figure 1:

Figure 2:

Figure 3:

Figure 4:

Figure 5:

Figure 6:

Figure 7:

Number of species according to the two species-delimitation methods (GMYC vs bPTP)_

Morphometric data of Hoplolaimus seinhorsti and Hoplolaimus pararobustus_ All measurements are in μm (except for ratio) and in the form: mean ± sd (range)_ Species included in this study are presented in the first two columns of the table_

List of unlabeled, mislabeled Hoplolaimus sequences on GenBank reassigned to corrected species in this study_

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