Skip to main content

Identification and a culture method for a Helicotylenchus microlobus from tomato in China

Abstract

Background

The nematodes of the genus Helicotylenchus are root parasites of a wide variety of plants, and certain species can cause serious damage to their hosts. During a survey of the plant-parasitic nematode associated with tomato, a population of Helicotylenchus was collected from tomato roots and soil samples. Thus, one of the objectives of the study was to confirm the specie of Helicotylenchus obtained from the tomato samples based on morphological and molecular characteristics. In addition, a mass pure culture of plant-parasitic nematodes is key to pathogenicity studies and many other biological studies. However, a successful mass rearing method for Helicotylenchus has not been reported. Thus, the other objective of the study was to establish a method of culturing Helicotylenchus.

Results

Based on both the morphological characteristics and molecular analysis of the internal transcribed spacer (ITS) and D2-D3 expansion region of 28S ribosomal RNA (rRNA) sequences the specimens were identified as Helicotylenchus microlobus. Phylogenetic analysis with the rRNA sequences of the ITS and 28S D2-D3 regions was consistent with molecular identification, suggesting this population formed a highly supported clade with other H. microlobus populations. Additionally, a method for culture of H. microlobus on carrot disks was established, and the effect of temperature on the reproduction rate (Rr) of H. microlobus was investigated. The optimum temperature for culturing H. microlobus on carrot disks was 27.5 °C and, after inoculation with 30 females of H. microlobus at 27.5 °C for 90 days, Rr reached 406.

Conclusions

To our knowledge, this is the first detailed description of H. microlobus from tomato in China. This study also demonstrated that the carrot disk method is suitable for the culture of H. microlobus. This study lays a foundation for other related research on H. microlobus, and has significance for the study of Helicotylenchus.

Peer Review reports

Background

Tomato (Solanum lycopersicum L.) is one of the most economically important members of the family Solanaceae and is cultivated worldwide [1]. It is one of the most important vegetable crops in China and is rich in minerals, vitamins, antioxidants and other micronutrients [2]. China has the largest area of tomato cultivation in the world, and Henan Province is the dominant production area for tomato cultivation [3]. Many plant pathogens can infect tomato, and nematodes perhaps are one of the important pathogens limiting tomato production worldwide and can cause severe economic losses [4].

The genus Helicotylenchus Steiner 1945 is considered one of the ten most important plant parasitic nematodes in the world [5]. Within the genus Helicotylenchus, more than 200 nominal species have been described worldwide [6]. The genus Helicotylenchus is classified as semi-endoparasitic that may occur in large numbers, causing plant growth reduction [7, 8]. After infection by Helicotylenchus, plants of outer layer of cortical tissue and the root system were damaged, further resulting in reduced ability of plants to absorb water and nutrients. For example, Helicotylenchus species associated with Musaceae damaged the cortical tissue of roots, and reduced the ability of roots for the uptake of water and nutrients [9]. H. microlobus infected Paspalum vaginatum causing brown lesions on their roots [10]; H. multicinctus, H. dihystera and H. erythrinae have been found to be harmful to banana and plantain crops around the world [9]. Inoculating H. dihystera on Olive seedlings caused 78% reduction in weight, and the development of the lateral roots occurred retardation [11]. Some studies suggests that H. pseudorobustus feeding in the cortical parenchyma of corn and soybean roots and causing serious damage [8, 12]. At present, 50 Helicotylenchus species are reported from China, and these species are reported from a variety of plants including ornamental plants, fruit trees, cucumber, rice, grape and pomegranate [13,14,15]. However, only H. dihystera is currently reported associated with tomatoes in China [16, 17]. At present, H. microlobus are not reported from tomato in China. Subbotin et al. recorded that H. microlobus was collected in California, Illinois, and Iowa, in the United States of America and in several European countries, including Spain, Italy and Russia [18]; Yan et al. reported H. microlobus infecting soybean in North Dakota [19]. Abraham and Dong reported H. microlobus in turfgrass in Korea [20].

In addition, a mass pure culture of plant-parasitic nematodes is key to pathogenicity studies and many other biological studies [21]. For most species of plant- parasitic nematodes, establishing a rapid and efficient culture method is a challenge. At present, only a small percentage of plant-parasitic nematodes can be successful cultured. The successfully establishment of an efficient culture method for Helicotylenchus has not been reported, and this increased the difficulty to study the pathogenicity and some biology of Helicotylenchus.

In 2019, during a survey of the plant-parasitic nematode associated with tomato, a population of Helicotylenchus was collected from tomato roots and soil samples in Zhuma village, Tongxu County of Kaifeng city, Henan Province, China. The objectives of this study were to confirm the specie of Helicotylenchus obtained from the tomato samples based on morphological and molecular characteristics and establish a method of culturing Helicotylenchus on carrot disks.

Results

Helicotylenchus microlobus Perry in Perry, Darling and Thorne, 1959

The Helicotylenchus individual population collected from tomato was photographed (Fig. 1). The morphometric data from the population closely resembled H. microlobus as described previously [18, 19, 22] (Table 1). Distance between dorsal esophageal gland opening and stylet knobs.

Fig. 1
figure 1

Light micrographs of Helicotylenchus microlobus female. A Entire body, B-D Lip region, e Anterior region, F-G Two genital branches, H Lateral lines, I The junction of genital gland and intestine, J Vulval region, K-N Tail region, O-P Lateral field at tail region. Scale bars: 50 µm (A) and 10 µm (B-P); an = annuli; s = stylet; sk = stylet knob; oc = ovary cells; lf = lateral field; mb = median bulb; eg = esophageal glands; vu = vulval; a = anal

Table 1 Morphometrics of females of Helicotylenchus microlobus

Female; Habitus spiral. (Fig. 1 A). Lip region hemispherical, with 4–5 annules (Fig. 1 B, C, D). Stylet robust, with rounded knobs that varied little in shape, 2–3 µm high and 4–6 µm wide (Fig. 1 B, C, D). Median pharyngeal bulb oval to rounded (Fig. 1 E, I). An excretory pore was immediately posterior to the hemizonid (Fig. 1 E). Two genital branches, both functional, outstretched (Fig. 1 F, G). Lateral field with four longitudinal lines (Fig. 1 H), absence of areolation in the tail region (Fig. 1 O, P). Inner lateral field incisures in tail region mostly fused distally into a Y-shaped configuration (Fig. 1 O, P). Pharyngeal glands overlapped the intestine ventrally (Fig. 1 E, I). Measurement of anal body diameter ranged from 12.7 to 14.4 µm (Fig. 1 K, L, M, N). Tail longer than the anal body diameter, with 6–13 ventral annuli, ending in a pronounced ventral projection, usually rounded terminally, without a mucro (Fig. 1 K, L, M, N). Tail tip without annulation or indistinctly annulated.

Male; Not observed.

Remarks: The specimens were identified as H. microlobus because of the presence of the lateral field not areolated on the tail, inner incisures of the lateral field fused distally for about two annuli in a Y-shaped pattern and tail projection not annulated. The several characteristics were consistent with the description of Siddiqi (1972) [23]. So, taking into consideration the results of our morphological and morphometric data, we consider the population as representatives of H. microlobus rather than H. pseudorobustus or another taxon. In this study, the morphological characteristics of the population of H. microlobus collected in this study were compared with data of Mwamula et al. (2020), Yan et al. (2017) and Subbotin et al. (2015) [18, 19, 22]. In comparison with the materials studied by Mwamula et al. (2020), the L (679.7 µm vs 732.5 µm), c (33.1 vs 37.7) and max body diameter values (25.4 µm vs 28.6 µm) for female nematodes were relatively smaller; the pharynx length (144.3 µm vs 123.6 µm) of measurements and m value (48.8 vs 43.7) were relatively larger [23]. In comparison with the North Dakota specimens studied by Yan et al. (2017), they differed in tail annules (10.0–14.0 vs 9.0–12.0) and a value (21.4–27.1 vs 25.6–28.1) [19]. Compared with the California specimens studied by Subbotin et al. (2015), the body length (679.7 µm vs 739.0 µm), anterior end to excretory pore (110.0 µm vs 128.0 µm) and stylet length (25.6 µm vs 28.9 µm) were relatively smaller; and Compared with the China specimens studied by Subbotin et al. (2015), the body length (679.7 µm vs 622.0 µm), b value (5.3 vs 4.7), Anterior to median bulb length (78.0 µm vs 58.0 µm), and tail length (20.7 µm vs 17.0 µm) were relatively larger [20].

Molecular characterization and phylogenetic relationships of H. microlobus

The primers TW81/AB28 and D2A/D3B were used to amplify the ITS and D2-D3 regions, respectively, of the 28S rRNA gene sequences of H. microlobus. The amplified PCR products were 1105 bp and 787 bp in length, respectively (Fig. 2). The obtained ITS sequences and the D2-D3 region of 28S rRNA sequences in this study were submitted to GenBank database. The ITS rRNA gene sequences obtained in this study (GenBank accession No. MZ2708013) showed 99.17%-99.89% similarity with H. microlobus sequences from the California populations (KM506859 and KM506860) and the Korea populations (MN764342 and MN764343). The obtained D2-D3 region of the 28S rRNA gene sequences of H. microlobus (MZ2707554) showed 99.2%-100% similarity with H. microlobus sequences from the Korea populations (MN764328, MN764324, MN764323 and MN7643253) and the Island populations (MG770481).

Fig. 2
figure 2

PCR amplification of the D2-D3 region of 28S rRNA and the ITS rRNA gene of Helicotylenchus microlobus. M: DL2000 Marker. 1: 28S. 2: ITS

Phylogenetic analysis within the genus Helicotylenchus based on ITS rRNA gene sequences was performed and contained 41 sequences with 954 positions in length. The 50% majority rule consensus tree inferred from the ITS data set by Bayesian analysis is shown in Fig. 3. The phylogenetic tree showed that the newly obtained sequence for H. microlobus (MZ2708013) formed a 100% supported clade with other H. microlobus population. Phylogenetic analysis within the genus Helicotylenchus based on the D2-D3 region of the 28S rRNA gene contained 57 sequences with 557 positions in length. The 50% majority rule consensus tree inferred from the 28S data set by Bayesian analysis is shown in Fig. 4. This phylogenetic tree indicated that the newly obtained sequence for H. microlobus (MZ2707554) formed a highly supported clade with H. microlobus and H. pseudorobustus type B (pp = 100%).

Fig. 3
figure 3

Bayesian tree of Helicotylenchus as inferred from ITS rRNA gene sequences under GTR + I + G model. Posterior probabilities more than 50% are given for appropriate clades. Newly obtained sequence is indicated in bold font

Fig. 4
figure 4

Bayesian tree of Helicotylenchus as inferred from the D2-D3 region of 28S rRNA gene sequences under GTR + I + G model. Posterior probabilities more than 50% are given for appropriate clades. Newly obtained sequence is indicated in bold font

Effects of temperature on the reproduction rate (Rr) of H. microlobus

At 90 days after inoculation with 30 females, reproduction occurred on each carrot disk, and the Rr reached 232, 406, and 53 at 25, 27.5 and 30 °C, respectively (Table 2). The nematode Rr at 27.5 °C was significantly higher than that at 25 and 30 °C (P < 0.05). In addition, when incubated at 25 and 27.5 °C for 90 days, H. microlobus gathered on the surface of the Petri dish (Fig. 5), and the number of nematodes reached 6947(35.9% females, 34.4% juveniles, 29.7% eggs and no males) and 12,190(34.0% females, 29.9% juveniles, 36.1% eggs and no males), respectively (Fig. 5) (Table. 2). At 90 days after inoculation with 30 females, the carrot disks presented obvious infection symptoms and turned brown or dark-brown. These results demonstrate that the carrot disk method is suitable for the culture of H. microlobus.

Table 2 Effect of temperature (Tm) on the reproduction of Helicotylenchus microlobus on carrot callus 90 days after inoculation with 30 females x
Fig. 5
figure 5

The carrot disks with disease symptoms and nematode populations at 25, 27.5 and 30 °C after 90 days. A: control without nematodes; B-D: the carrot disks with disease symptoms at 25 ℃, 27.5 ℃ and 30 ℃, respectively; E: nematode population; F–H: microscopic images of nematode populations; e = egg; n = nematode; Scale bars: F: 400 µm; G: 200 µm; H: 25 µm

Discussion

Plant-parasitic nematodes are some of the most important pathogens of tomato. Meloidogyne, Helicotylenchus, Pratylenchus, Tylenchorhynchus and Aphelenchoides can infect tomato roots and cause severe economic losses [24]. Different Helicotylenchus have been reported from the rhizosphere soil of tomato in many countries. For example, in Turkey, H. digonicus, H. tunisiensis and H. varicaudatus have been reported from tomato rhizosphere soils [25]. Kim et al. (2014) reported that H. dihystera can suppress the growth of tomato and this species was also reported from tomato in China [26]. H. thornei Roman, 1965 is also described from soil around the roots of tomato in Ludhiana, India [27].

The genus Helicotylenchus known to contain various species complexes that normally exhibit similar diagnostic characteristics [18]. As intraspecific variability in characters may be influenced by environmental conditions, species delineation within the genus is not always easy [28]. This adds to identification problems and can leads to some misidentifications within the genus, due to lack of consensus among different taxonomists on the validity of some species [18, 29]. Therefore, biochemical and molecular information are more and more important in nematode taxonomy, however, these approaches should still be integrated with morphological characteristics [30].

H. microlobus was considered as a junior synonym of H. pseudorobustus by Sher (1966) because of their indistinguishable morphological characteristics, and this propose was accepted by Sauer and Winoto (1975), Fortuner (2018), and Divsalar et al. (2020) but was not agreed with by Siddiqi (1972, 2000), Subbotin et al. (2015) and Mwamula et al. (2020) [6, 18, 22, 23, 29, 31, 32]. Siddiqi (1972) proposed that H. microlobus differed from H. pseudorobustus by the non areolated lateral field in tail region (areolated in H. pseudorobustus), and inner lateral lines fusion as Y-shaped in the tail region (M- or U-shaped in H. pseudorobustus) [18, 23]. In this study, the morphological characteristics of this population were consistent with the characteristics of H. microlobus described by Siddiqi (1972), Subbotin et al. (2015) and Mwamula et al. (2020) [18, 22, 23]. When compared with H. microlobus species, the obtained ITS rRNA sequence showed 99.17%-99.89% homology with both H. microlobus sequences from California (KM506859 and KM506860), Korea (MN764342 and MN764343) and Spain (KM506862). In contrast, it had only 93% sequence identity with isolates of H. pseudorobustus (KM506835) from California. And, the obtained 28S rRNA sequence showed 99.2%-100% homology with both H. microlobus sequences from Korea (MN764328, MN764324, MN764323 and MN7643253) and Island (MG770481). In contrast, it had only 91% sequence identity with isolates of H. pseudorobustus (KU722387) from Iran. In addition, the results of the phylogenetic analysis of the ITS rRNA gene region showed that H. microlobus and H. pseudorobustus were clearly divided into two different clades; the results of the phylogenetic analysis of the 28S rRNA gene D2-D3 gene region showed that H. pseudorobustus type B (DQ328748; DQ328749; FJ485649) were clustered together with H. microlobus. Subbotin et al. (2011, 2015) proposed that a species group complex for H. pseudorobustus includes at least H. pseudorobustus type A and H. pseudorobustus type B, according to morphological and molecular analyses. According to the results of Subbotin et al. (2015), H. pseudorobustus type B should be H. microlobus and phylogenetic relationships of H. pseudorobustus type B (DQ328748; DQ328749; FJ485649) were clustered together with H. microlobus. Therefore, our results were consistent with the results of analysis of Helicotylenchus species by Subbotin et al. (2011, 2015). Taking into consideration the results of our integrative morphological and molecular analyses of the H. microlobus population, we considered the populations as representatives of H. microlobus rather than H. pseudorobustus. This is the first report of H. microlobus from tomato in China using morphological and molecular characterization.

Obtaining a large number of plant-parasitic nematodes is very important because many types of studies can be performed with these nematodes, such as pathogenicity tests and biological and genetic studies [21]. For a long time, researchers have been looking for methods to culture plant-parasitic nematodes using plant tissues [24, 25]. Some culture methods have been successfully employed, and there are great differences in these methods. For example, Aphelenchoides besseyi, Ditylenchus destructor and Bursaphelenchus xylophilus can be cultured on certain fungi [33,34,35]. A. ritzemabosi and D. dipsaci can reproduce rapidly on alfalfa tissue [36]. The carrot callus method is suitable for culturing A. ritzemabosi, A. besseyi, R. similis, and most species of Pratylenchus [37, 38]. Over the years, some researchers tried to culture certain Helicotylenchus species in vitro, but failed. For example, Brown and Vessey demonstrated that H. multicinctus failed to survive when cultured on banana fruit callus [39]; Khera and Zuckerman cultured H. erythrinae on tissues of carrot, sweet potato, tobacco and tomato, but nematodes all failed to reproduction on these tissues [40]; Kagoda et al. reported that H. multicinctus failed to rear on carrot discs [41]. One Helicotylenchus species and H. dihystera have been reported to successfully produce progenies after inoculating single female in host-plants pots [42, 43]. However, the method culturing the Helicotylenchus species in host-plants pots was susceptible to contamination, time-consuming and difficult to separate the progeny from the pots. Sterile carrot disks are usually regarded as a relatively low-cost, straightforward and efficient method for culturing some nematodes that results in greater nematode multiplication compared with other methods [21]. Our study is the first to successfully establish an artificial culture method for H. microlobus on carrot disks. The succcesful rearing of H. microlobus make other related biological studies of H. microlobus possible.

Plant growth inhibition has been reported associated with several Helicotylenchus species that have also increased secondary infections of fungal pathogens [44]. Studies have shown that when H. dihystera and Pseudomonas solanacearum present together, tomato wilting was much more serious than when present alone, and when H. dihystera associated with P. caryophylli, carnation wilting was also significantly increased [12, 45]. Therefore, whether there is such a synergistic relationship between H. microlobus and certain bacteria that may led to more serious disease on tomato should be further investigated.

Conclusions

In our study, both morphological and molecular analyses showed that the species of the Helicotylenchus population was H. microlobus. This is the first report of H. microlobus from tomato in China. We established that the carrot disk method is suitable for rearing of H. microlobus on carrot disks, and the optimum temperature for H. microlobus culture on carrot disks was 27.5 °C, and the Rr reached 406 after 90 days of inoculation with 30 females.

Methods

Nematode collection

In August 2019, five samples of roots and corresponding rhizosphere soils were collected from a tomato (cv. Maohong 801) field near Zhuma village in Tongxu County of Kaifeng city, Henan Province, China. Each sample consisted of at least five sub samples collected from patches of poor growth. Samples were placed in plastic bags, sealed transported to the laboratory in refrigerated counter and stored at 16 to 18 °C [46]. Nematodes were extracted from tomato soil and macerated root samples using the modified Baermann funnel method [47].

In vitro rearing of nematodes

Carrot disks were prepared in the following way. The surface of a carrot was sterilized with 95% ethanol. The carrot was peeled with a sterile knife and cut into 6 mm thick disks. Each carrot tissue was placed in a 6-cm-diameter petri dish and maintained at 25 °C for 15 days for later use. One female from the collected specimens was selected and surface sterilized for 6 h with 0.3% streptomycin sulfate, and then transferred to carrot disks. and the petri dishes were sealed with parafilm and then kept in a darkened incubator at 25 ℃for 15 weeks. After that, the single female Helicotyenchus population cultured on carrot disks were used for morphological and molecular analysis.

Morphological identification

Nematodes were heat-killed in water, fixed in FG (formalin: glycerin: water = 10:1:89), and processed to glycerin by the formalin glycerin method [47]. Photomicrographs and morphometric data of the Helicotylenchus specimens were obtained using a Nikon Eclipse Ti-S microscope (Japan). Images of key morphological features were processed using Photoshop CS5. The de Man formula was used for measurements [30]. All measurements are expressed in micrometers (μm) [48].

Molecular characterization and phylogenetic relationships

DNA from one Helicotylenchus specimen was extracted using proteinase K-based lysis [49]. The rRNA-internal transcribed spacer (ITS) region and the D2-D3 region of the 28S rRNA gene were amplified with primers TW81/AB28 (5´-GTTTCCGTAGGTGAACCTGC-3´/5´-ATATGCTTAAGTTCAGCGGGT-3´) [50] and primers D2A-D3B (5´-ACAAGTACCGTGAGGGAAAGTTG-3´/5´TCGGAAGGAACCAGCTACTA-3´) [51], respectively. The processes of PCR amplification and cloning were carried out according to the method of Wang et al. [52]. Sequencing was performed by Sangon Biotech Co. Ltd. (Shanghai, PR China). The newly obtained DNA sequences were submitted to the NCBI GenBank (https://submit.ncbi.nlm.nih.gov/subs/genbank/) database.

The obtained ITS region and D2-D3 region of the 28S sequences were subjected to multiple alignment using the MAFFT Q-INS-i algorithm [53] with other Helicotylenchus species sequences published in the NCBI GenBank database. Outgroup taxa were selected based on a previous study [54]. Sequence datasets were analysed with Bayesian inference (BI) using MrBayes 3.2.6 [55] under the best-fit model of GTR + G + I, according to Akaike Information Criteria [56]. BI analysis for each gene was run with a random starting tree and four Markov chains for 1 × 106 generations. The Markov chains were sampled at intervals of 100 generations. After discarding burns in samples, the remaining samples were used to generate a 50% majority rule consensus tree. Posterior probabilities (pp) are given on appropriate clades.

Reproduction tests

Using the carrot disk method, experiments were undertaken to determine the reproductive potential of H. microlobus and also to determine the optimum temperature for rearing H. microlobus on carrot disks. In the experiment, 30 females were surface sterilized for 6 h with 0.3% streptomycin sulfate and then transferred to a carrot disk in a petri dish. The petri dishes were sealed with parafilm and incubated in a darkened incubator at 25, 27.5, and 30 °C, respectively. The number of nematodes and reproduction rate (Rr = final number of nematodes/initial number of nematodes) on each carrot disk were determined at 90 days after inoculation.

A maceration method was used to collect the nematodes [46]: the carrot disks were placed in sterile water and macerated in a blender. The suspension was poured through 0.250-mm and 0.150-mm-pore sieves. The nematode suspension was collected in a beaker and the carrot tissues discarded. The nematode suspension was left to settle for at least 4 h and the supernatant was removed by pipettor. The nematodes were enumerated to determine whether H. microlobus reproduction had occurred and the Rr (final number of nematodes/initial number of nematodes) determined. There were five replicates for each experiment, and each experiment was conducted twice. Data on H. microlobus cultured on carrot disks under different temperatures were subjected to a one-way analysis of variance (ANOVA), and differences were tested using Duncan’s multiple range test (DMRT) at the 5% significance level using SPSS software (ver. 13.0; SPSS Inc., Chicago). The result of this experiments are given in Table.

Availability of data and materials

The datasets supporting the conclusions of this article are available in the GenBank repository (https://www.ncbi.nlm.nih.gov/). The newly obtained rRNA sequences in this study were deposited in the NCBI GenBank (https://submit.ncbi.nlm.nih.gov/subs/genbank/) database for a BLAST search (accession no. MZ2708013 and MZ2707554).

References

  1. Zheng W. Investigation and analysis of farmers’ production input and output in main tomato producing areas. Rural Econ Sci Technol. 2019;30(09):112–4 [In Chinese].

    Google Scholar 

  2. Tao XY, Wu Q, Aalim H, Li L, Ying T. Effects of exogenous abscisic acid on bioactive components and antioxidant capacity of postharvest tomato during ripening. Molecules. 2020;25:1346–64.

    Article  CAS  PubMed Central  Google Scholar 

  3. Diao Y, Larsen M, Kamvar ZN, Zhang C, Li S, Wang WZ, et al. Genetic differentiation and clonal expansion of Chinese botrytis cinerea populations from tomato and other crops in China. Phytopathol. 2019;110(2):428–39.

    Article  Google Scholar 

  4. Li Y, Zhao XY, Song YY, Sun MR, Xia YH, Yuan HX, et al. Parasitism and pathogenicity of five populations of Pratylenchus coffeae to Solanum lycopersicum. J China Agri Uni. 2021;26(10):81–9 [In Chinese].

    CAS  Google Scholar 

  5. Sasser JN. Plant-Parasitic Nematodes: The farmer’s hidden enemy. department of plant pathology, North Carolina State University, Raleigh, USA and the consortium for international Crop Protection. 1989. p. 115.

    Google Scholar 

  6. Divsalar N, Shokoohi E, Marais M, Mashela PW. Molecular and morphological characters of Helicotylenchus Steiner, 1945 species from Iran with a note on the identity of H. pseudorobustus (Steiner, 1914) Golden, 1956. Zootaxa. 2020;4789(1):266–80.

    Article  Google Scholar 

  7. Yeates GW, Bongers T, Goede RGM, Freckman DW, Georgieva SS. Feeding habits in soil nematode families and genera-An outline for soil ecologists. J Nematol. 1993;25:315–31.

    CAS  PubMed  PubMed Central  Google Scholar 

  8. Norton DC, Frederick LR, Ponchillia PE, Nyhan JW. Correlations of nematodes and soil properties in soybean fields. J Nematol. 1971;3(2):154–63.

    CAS  PubMed  PubMed Central  Google Scholar 

  9. Riascos-Ortiz D, Mosquera-Espinosa AT, De Agudelo FV, de Oliveira CMG, Muñoz-Florez JE. An integrative approach to the study of Helicotylenchus (Nematoda: Hoplolaimidae) Colombian and Brazilian populations associated with Musa crops. J Nematol. 2020;52:1–19.

    Article  PubMed  CAS  Google Scholar 

  10. Jagdale GB, Ali ME, Waliullah S, Hajihassani A, Martin K, Martinez-Espinoza AD. First Report of the Spiral Nematode Helicotylenchus microlobus Infecting Paspalum vaginatum, Seashore Paspalum Turfgrass, in Georgia, USA. Plant Dis. 2020;104:2739.

    Article  Google Scholar 

  11. Diab KA, El-Eraki S. Plant-parasitic nematodes associated with olive decline in the United Arab Republic. Plant Dis. 1968;52:150–4.

    Google Scholar 

  12. Taylor DP. Biology and host-parasite relationships of the spiral nematode Helicotylenchus microlobus. J Parasitol. 1961;28:60–6.

    Google Scholar 

  13. Luo SL, Sun DT, He PC. Description of some species in genus Helicotylenchus around the grape roots from four provinces in China. Plant Protect Sci. 2002;28:5–8.

    Google Scholar 

  14. Guo Z, Chen SP, Chen YH, Liao JL. Primary identification and control of some ornamental plant parasites nematode in Guangzhou. Guangdong Agri Sci. 2006;2:53–4 [in Chinese].

    Google Scholar 

  15. Zhou YL, Guo YL, Zhang W, Hu XQ. Preliminary description on megranate parasitical nematodes in Yunnan. Acta Agri Univ Jiangxiensis. 2007;29:937–9 [in Chinese].

    Google Scholar 

  16. Qi ZR, Liu TH, Wang N, Wang X, Zhu HR, Li HM. Occurrence and species identification of nematode parasites of vegetables and horticultural plant seedlings in export plantations. J Nanjing Agri Uni. 2014;37:93–100 [in Chinese].

    CAS  Google Scholar 

  17. Li H, Gao JM, Zhang Y. Types of vegetable garden plant parasitic nematodes in Taigu. J Shanxi Agri Sci. 2009;37:54–9 [in Chinese].

    Google Scholar 

  18. Subbotin SA, Vovlas N, Yeates GW, Hallmann J, Kiewnick S, Chizhov VN, et al. Morphological and molecular characterisation of Helicotylenchus pseudorobustus (Steiner, 1914) Golden, 1956 and related species (Tylenchida: Hoplolaimidae) with a phylogeny of the genus. Nematol. 2015;17:25–52.

    Article  Google Scholar 

  19. Yan G, Plaisance A, Huang D, Handoo ZA. First report of the spiral nematode Helicotylenchus microlobus infecting soybean in North Dakota. J Nematol. 2017;49:1–1.

    Article  PubMed  PubMed Central  Google Scholar 

  20. Abraham OM, Dong WL. Occurrence of plant-parasitic nematodes of turfgrass in Korea. Plant Pathol J. 2021;37:446–54.

    Article  Google Scholar 

  21. Wang K, Li Y, Xie H, Wu WJ, Xu CL. Pin nematode slow decline of Anthurium andraeanum, a new disease caused by the pin nematode Paratylenchus shenzhenensis. Plant Dis. 2016;100:940–5.

    Article  CAS  PubMed  Google Scholar 

  22. Mwamula AO, Kim YH, Kim YH, Han G, Lee DW. Characterization of a new spiral nematode, Helicotylenchus asiaticus n. sp. and three known species from Korea; with comments on the validity of Helicotylenchus microlobus Perry in Perry, Darling and Thorne, 1959. Eur J Plant Pathol. 2020;157:565–81.

    Article  CAS  Google Scholar 

  23. Siddiqi MR. On the genus Helicotylenchus Steiner, 1945 (Nematoda: Tylenchida), with descriptions of nine new species. Nematologica. 1972;18:74–91.

    Article  Google Scholar 

  24. Hong SC. Introduction of several root-lesion nematodes on crops in Liaoning Province. J Liaoning Agri Technical College. 2001;3:12–4 [in Chinese].

    Google Scholar 

  25. Kepenekçi İ, Ökten ME. Honey species in the genus Helicotylenchus (Tylenchda, Hoplolaimidae) detected in tomato planted areas that interact with havu in Beypazar (Ankara) ilesi. Turk entomo magazine. 1996;20:137–48 [in Turkish].

    Google Scholar 

  26. Kim D, Ryu Y, Lee Y, Choi I, Hu C. Effect of density of Helicotylenchus dihystera on growth of Solanum lycopersicum. Research in Plant Disease. 2014;20:107–11.

    Article  Google Scholar 

  27. Gupta NK, Chhabra HK. Helicotylenchus thornei n. sp. (Nematoda: Hoplolaiminae) from a tomato plant field in Ludhiana, Punjab. Research Bulletin of the Panjab University of Science. In: Pakistan, 1966.

  28. Fortuner R, Merny G, Roux C. Morphometrical variability in Helicotylenchus Steiner, 1945. 3: Observations on African populations of Helicotylenchus dihystera and considerations on related species. Revue de Nématologie. 1981;10:1–2.

    Google Scholar 

  29. Fortuner R, Louis PY, Geniet D. On the morphometric identity of populations of Helicotylenchus pseudorobustus (Steiner, 1914) Golden, 1956 (Tylenchida: Hoplolaimidae). Nematology. 2018;20:423–39.

    Article  Google Scholar 

  30. Castillo P, Vovlas N. Pratylenchus (Nematoda: Pratylenchidae): diagnosis, biology, pathogenicity and management. Leiden: Brill; 2007.

    Book  Google Scholar 

  31. Sher SA. Revision of the Hoplolaiminae (Nematoda). VI. Helicotylenchus Steiner, 1945. Nematologica. 1966;12:1–56.

    Article  Google Scholar 

  32. Sauer MR, Winoto R. The genus Helicotylenchus Steiner, 1945 in West Malaysia. Nematologica. 1975;21:341–50.

    Article  Google Scholar 

  33. Liu B, Zheng JW. Monoxenic culture of Ditylenchus destructor on Botrytis cinerea. Acta Agric Zhejiangensis. 2006;18:445–7 [in Chinese].

    Google Scholar 

  34. Wan SJ, Duan YX, Jin YY, Chen LJ. Artificial rearing of the rice white-tip nematode (Aphelenchoides besseyi). Plant Protect Sci. 2008;34:46–8.

    Google Scholar 

  35. Zhu LH, Ye J, Negi S, Xu XL, Wang ZL, Ji JY. Pathogenicity of aseptic Bursaphelenchus xylophilus. PLoS ONE. 2012;7:e3809.

    Google Scholar 

  36. Krusberg LR. Studies on the culturing and parasitism of plant-parasitic nematodes, in particular Ditylenchus dipsaci and Aphelenchoides ritzeiwabosi on alfalfa tissues. Nematologica. 1961;6:181–200.

    Article  Google Scholar 

  37. Pei Y, Luo AL, Xie H, Yang ZF, Cheng X, Xu CL. Reproductive fitness of 15 Aphelenchoides besseyi populations from China. J Northwest A & F Univ. 2010;38:165–70 [in Chinese].

    Google Scholar 

  38. Peng XF, Chen DQ, Wang DW, Wang K, Wu WJ, Xu CL, Xie H. Culture conditions and reproductive characteristics of Aphelenchoides ritzemabosi on callus. J Huazhong Agri Uni. 2015;34:1–4 [in Chinese].

    CAS  Google Scholar 

  39. Brown SM, Vessey JC. Rearing of Radopholus similis on banana fruit callus. Revue de Nematologie. 1985;8:179–90.

    Google Scholar 

  40. Khera S, Zuckerman BM. Studies on the culturing of certain ectoparasitic nematodes on plant callus tissue. Nematologica. 1962;8:272–4.

    Article  Google Scholar 

  41. Kagoda F, Coyne DL, Mbiru E, Derera J, Tongoona P. Monoxenic culture of Pratylenchus zeae on carrot discs. Nematol medit. 2010;38:107–8.

    Google Scholar 

  42. Fortuner R. Morphometrical variability in Helicotylenchus Steiner, 1945 1. The progeny of a single female. Revue Nematol. 1979;2(2):197–202.

    Google Scholar 

  43. Fortuner R, Quénéhervé P. Morphometrical variability in Helicotylenchus Steiner, 1945. 2: Influence of the host on H. dihystera (cobb, 1893) Sher, 1961. Revue Nematol. 1980;3(2):291–6.

    Google Scholar 

  44. Van den Berg E, Marais M, Gaidashova S, Tiedt LR. Hoplolaimidae Filip’ev, 1934 (Nemata) from Rwandan banana fields. Afri Plant Protect. 2003;9:31–42.

    Google Scholar 

  45. Libman G, Leach JG, Adams RE. Role of certain plant-parasitic nematodes in infection of tomatoes by Pseudomonas solanacearum. Phytopathol. 1964;54:151–3.

    Google Scholar 

  46. Hooper DJ, Hallman J, Subbotin SA. Methods for extraction, processing and detection of plant and soil nematodes. In: Luc M, Sikora RA, Bridge J, editors. Plant Parasitic Nematodes in Subtropical and Tropical Agriculture. Wallingford, UK: CABI Publishing; 2005. p. 53–86.

    Chapter  Google Scholar 

  47. Xie H. Taxonomy of plant nematodes. 2nd ed. Beijing: Higher Education Press; 2005.

    Google Scholar 

  48. Xia YH, Li J, Sun MR, Lei B, Li HL, Li Y, Wang K. Identification and pathogenicity of Pratylenchus scribneri on tomato in Sichuan Province of People’s Republic of China. J Helminthol. 2022;96:1–9.

    Article  Google Scholar 

  49. Wang JL, Zhang JC, Gu JF. Method of extract DNA from a single nematode. Plant Quarantine. 2011;25:32–5 [in Chinese].

    Google Scholar 

  50. Sturhan SA, Sturhan D, Chizhov VN, Vovlas N, Baldwin JG. Phylogenetic analysis of Tylenchida Thorne, 1949 as inferred from D2 and D3 expansion fragments of the 28S rRNA gene sequences. Nematol. 2006;8:455–74.

    Article  Google Scholar 

  51. De Ley P, Felix MA, Frisse LM, Steven AN. Molecular and morphological characterization of two reproductively isolated species with mirror-image anatomy (Nematoda: Cephalobidae). Nematol. 1999;1:591–612.

    Article  Google Scholar 

  52. Wang S, Liu YK, Xia YH, Hao PH, Wang K, Li HL, Li Y. Identification and pathogenicity of a root-lesion nematode species on tobacco in Henan. J Northwest A F Univ. 2021;49:1–9 [in Chinese].

    Google Scholar 

  53. Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S. MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol. 2011;28:2731–9.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Rybarczyk-Mydłowska K, Dmowska E, Kowalewska K. Phylogenetic studies on three Helicotylenchus species based on 28S rDNA and mtCOI sequence data. J Nematol. 2019;51:1–17.

    Article  PubMed  CAS  Google Scholar 

  55. Huelsenbeck JP, Ronquist F. Mrbayes: Bayesian inference of phylogenetic trees. Bioinformatics. 2001;17:754–5.

    Article  CAS  PubMed  Google Scholar 

  56. Nylander JA. Mr Model test 2.3. Program distributed by the author. Uppsala: Evolutionary Biology Centre, Uppsala University; 2004.

    Google Scholar 

Download references

Acknowledgements

We are grateful for the aid of CX Liu and YN Bi. We thank two anonymous reviewers and the editor for their valuable comments.

Funding

Our works were supported by the Open Project of Key Laboratory of Crop Ecophysiology and Farming System in Desert Oasis Region, Ministry of Agriculture and Rural Affairs (No. 25107020–202102), Xinjiang Green Pesticide Development and Application Technology Research and Innovation Team of Tianshan Innovation Team Plan of Xinjiang Uygur Autonomous Region (No. 2020D14001), and the Key Scientific Research Projects of Colleges and Universities in Henan Province of China (No. 20A210022).

Author information

Authors and Affiliations

Authors

Contributions

YH Xia, K Wang and Y Li conceived and designed the study, and YH Xia, J Li and FF Xu performed the experiments, YH Xia, B Lei, Y Li and HL Li analyzed the data and YH Xia, K Wang and Y Li wrote the manuscript. All authors approved the final version of the manuscript.

Corresponding authors

Correspondence to Ke Wang or Yu Li.

Ethics declarations

Competing interests

The authors declare no competing interests.

Ethics approval and consent to participate

We collected samples of roots and corresponding rhizosphere soils in areas where no specific permits were required. The land used as the collection area is neither privately owned nor protected in any way, and the field studies did not involve endangered or protected species. Procedures for field sample collection were explained to village authorities and their verbal agreement was obtained before collected samples. All experimental studies on plants were complied with relevant institutional, national, and international guidelines and legislation.

Consent for publication

Not applicable.

Conflict of interests

The authors of this work declare that there is no conflict of interest.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Xia, YH., Li, J., Xu, FF. et al. Identification and a culture method for a Helicotylenchus microlobus from tomato in China. BMC Zool 7, 42 (2022). https://doi.org/10.1186/s40850-022-00144-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s40850-022-00144-7

Keywords