Morphological adjustment in free-living Steinernema feltiae infective juveniles to increasing concentration of Nemafric-BL phytonematicide

Autoři: Phatu W. Mashela aff001;  Ebrahim Shokoohi aff001;  Kgabo M. Pofu aff001
Působiště autorů: University of Limpopo, Green Biotechnologies Research Centre of Excellence, Sovenga, Republic of South Africa aff001;  Agricultural Research Council-VOP, Pretoria, Republic of South Africa aff002
Vyšlo v časopise: PLoS ONE 15(1)
Kategorie: Research Article
prolekare.web.journal.doi_sk: 10.1371/journal.pone.0227448


Third-stage larvae (L3) of Steinernema feltiae exist as free-living infective juveniles (IJ), with suspended development activities. In contrast, parasitic stages (L1, L2, L4, adult) have mutualistic relations with Xenorhabdus species bacteria, along with unique morphological changes and development inside the cadaver of host insects and/or plant-parasitic nematodes. Commercial IJ strains are tolerant to cucurbitacin-containing phytonematicides, but we have scant information on how morphological adjustments in IJ are achieved. In this study, we investigated the nature of morphological adjustments in commercial S. feltiae IJ strains to Nemafric-BL phytonematicide, which contains cucurbitacin B as active ingredient. Post-72 h exposure to phytonematicide concentration, IJ specimens were fixed on mounting slides. Length (body, excretory pore to anterior end, pharynx, rectum, stoma, tail), diameter (head width, neck base, mid-body, anal body), cuticle thickness and De Man ratios were measured with a computer software programme attached to Omax light microscope. Morphometric data against increasing phytonematicide concentration exhibited either density-dependent quadratic, linear or neutral relations. Increase in body length at low phytonematicide concentration was accompanied by decrease in tail length and pharynx length during muscle contraction when IJ were still alive. After death at high phytonematicide concentration, the opposite morphometric effects ensued due to muscle relaxation. The observed changes in morphometric structures were explained on the basis of morphological adjustments that modulated volumes of pseudocoelom cavity in IJ. The modulation is intended to maintain hydrostatic pressure within permissible upper limits in order to avoid structural damage to internal organs embedded in the pseudocoelom fluids.

Klíčová slova:

Head – Hydrostatic pressure – Morphometry – Muscle contraction – Nematode infections – Pharynx – Plant pathology – Rectum


1. Hunt DJ, Nguyen B (eds). Nematology monograph and perspectives: Advances in entomopathogenic nematode taxonomy and phylogeny. Brill, Leiden-Boston. 2016.

2. Khan SA, Javed N, Kamran M, Abbas H, Safdar A, ul Haq I. Management of Meloidogyne incognita Race 1 through the use of entomopathogenic nematodes in tomato. Pak J Zool. 2016;48:763–768.

3. Lacey LA, Georgis R. Entomopathogenic nematodes for control of insect-pests above and below ground with comments on commercial production. J Nematol. 2012;44:218. 23482993

4. Lewis EE, Campbell J, Griffin C, Kaya H, Peters A. Behavioural ecology of entomopathogenic nematodes. Biol Control. 2006;38:66–79.

5. Molina JP, Dolinski C, Souza RM, Lewis EE. Effect of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) on Meloidogyne mayaguensis Rammah and Hirschmann (Tylenchida: Meloidoginidae) infection in tomato plants. J Nematol. 2007;39:338–342. 19259509

6. Vashisth S, Chandel YS, Sharma PK. Entomopathogenic nematodes–A review. Agric Rev. 2013;34:163–175.

7. Ferreira T, Malan AP. Xenorhabdus and Photorhabdus, bacterial symbionts of the entomopathogenic nematodes Steinernema and Heterorhabditis and their in vitro liquid mass culture. Afr Entomol. 2014;22:1–14.

8. Dillman AR, Sternberg P. Entomopathogenic nematodes. Cur Biol. 2012 5;22(11):R430–431.

9. Kaya HK, Gaugler R. Entomopathogenic nematodes. Annu Rev Entomol. 1993;38:181–206.

10. Madaure JT, Mashela PW, De Waele D. Response of entomopathogenic nematode, Steinernema feltiae to cucurbitacin-containing Nemafric-BL phytonematicide. Res Crops. 2017;18:739–744.

11. Lu D, Macchietto M, Chang D, Barros MM, Baldwin J, Mortazavi A, et al. Activated entomopathogenic nematode infective juveniles release lethal venom proteins. PLoS Pathog. 2017;13(4):1–31.

12. Madaure JT, Mashela PW, De Waele D. Compatibility of Steinernema feltiae with Nemarioc AL phytonematicide. Transyl Rev. 2018;26:8709–8713.

13. Mashela PW, De Waele D, Dube Z, Khosa MC, Pofu KM, Tefu G, et al. Alternative nematode management strategies. In: Nematology in South Africa: A View from the 21st Century. Fourie H, Spaull VW, Jones RK, Daneel MS, De Waele D. (eds.). Springer International Publishing: Heidelberg, Switzerland. 2017.

14. Krishnayya PV, Grewal PS. Effect of neem and selected fungicides on viability and virulence of the entomopathogenic nematode, Steinernema feltiae. Biocontrol Sci Technol. 2002;12:259–266.

15. De Nardo EAB, Grewal PS. Compatibility of Steinernema feltiae (Nematoda: Steinernematidae) with pesticides and plant growth regulators used in glasshouse plant production. Biocontrol Sci Technol. 2003;13:441–448.

16. Guitterez C, Campos-Herrera R, Jiménez J. Comparative study of the effect of selected agrochemical products on Steinernema feltiae (Rhabditida: Steinernematidae). Biocontrol Sci Technol. 2008;18:101–108.

17. Dube ZP, Mashela PW. Confirmation of bioactivities of active ingredients of Nemarioc-AL and Nemafric-BL phytonematicides. Acta Agr Scand Soil Plant Sci. 2017;67:571–575.

18. Grewal P, Lewis E, Gaugler R, Campbell J. Host finding behaviour as predictor of foraging strategy in entomopathogenic nematodes. Parasitol. 1994;108:207–215.

19. Chang DZ, Serra L, Lu D, Mortazavi A, Dillman AR. A core set of venom proteins is released by entomopathogenic nematodes in the genus Steinernema. PLOS Pathog 2019;15(5):1–29.

20. Radová Š. Effect of selected pesticides on the vitality and virulence of the entomopathogenic nematode Steinernema feltiae (Nematoda: Steinernematidae). Plant Protect Sci. 2010;46:83–88.

21. Tseke PE, Mashela PW. Efficacy of Nemafric-BL phytonematicide from fresh Cucumis africanus fruit on suppression of root-knot nematodes and growth of tomato plants. Res Crops. 2017;18:289–293.

22. Higa T, Parr JF. Beneficial and effective microorganisms for a sustainable agriculture and environment. International Nature Farming Research Centre: Atami, Japan. 1994

23. De Grisse AT. Contribution to the morphology and the systematics of the Criconematidae (Taylor, 1936) Thorne, 1949. Faculty of Agricultural Sciences, Gent, Belgium. 1969

24. Causton DR. Contemporary biology: A biologist’s mathematics. London: Bedford Square. 1977

25. Gomez KA, Gomez AA. Statistical procedures for agricultural research. New York, Wiley. 1984.

26. Liu DL, Johnson IR, Lovett JV. Mathematical modelling of allelopathy. III: A model for curve-fitting allelochemical dose responses. Nonlin Biol Toxicol Med. 2003;1:37–50.

27. Harris JE, Crofton HD. Structure and function in the nematodes: Internal pressure and cuticular structure in Ascaris. J Exp Biol. 1957;34:111–130.

28. Bird AF, Bird J. The structure of nematodes. Academic Press, New York. 1991.

29. Shokoohi E. Plant nematology with emphasis on plant-parasitic nematodes. [In Persian with English abstract]. Danesh Negar publishing, Tehran, Iran. pp 272. 2019.

30. Wharton DA. A functional biology of nematodes. Croom Helm, London. United Kingdom, 1986.

31. Basyoni MMA, Rizk EMA. Nematodes ultrastructure: Complex systems and processes. J Parasit Dis. 2016;40:1130–1140. doi: 10.1007/s12639-015-0707-8 27876901

32. Dube ZP, Khosa MC. A preliminary study of the ultrastructure of Meloidogyne incognita second-stage juveniles exposed to cucurbitacins. Proc Symp Nematol Soc Sn Afr. 2019;22:17.

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