Rev 12/16/2024
Review general characteristics of the genus Meloidogyne.
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Second-stage juvenile
Meloidogyne minor has been found primarily on golf courses and sports fields in the Netherlands, Belgium, United Kingdom, Ireland, Chile, and the United States (Washington State) (Elling, 2013).
It also occurs in coastal dunes in Europe and there is concern that it is spreading throughout northwest Europe.
Easily spread through sod that is brought in and rolled out rather than planted as seed.
It could easily be spread by contamination of footwear and sports equipment.
Due to the risk of spread, the European and Mediterranean Plant Protection Organisation (EPPO) has placed M. minor on its alert list (Elling, 2013).
Yellow patches on golf greens constructed on sandy soils per USGA guidelines.
Meloidogyne minor is copnsidered a serious threat to turfgrass in north-west Europe, and has a broad host range that includes other economically important plants (Morris et al., 2011)..
Considered an A-rated pest in California, USA, based upon its host range and potential for causing substantial economic losses (Martin, 2024)..
Sedentary endoparasite.
Feeding site establishment and development typical of genus.
Type Hoste: potato (Solanum tuberosum)
Meloidogyne minor could spread to agronomic crops as its host range includes carrots, alfalfa, oat, lettuce, and tomato under greenhouse conditions. It reproduces on potato roots and tubers under field conditions (Elling, 2013).
Under field conditions, the nematode failed to reproduce on sugar beet, maize, and rye .
Ecophysiological Parameters:
Haploid chromosome number n=17; although males are present, the nematode is assumed to reproduce by facultative meiotic parthenogenesis. The egg nucleus undergoes a meiotic reduction division; one member of each pair of chromatids remains in a haploid nucleus and the other in a polar body. If fertilization by a male sperm occurs, the diploid number of chromosomes is restored. Otherwise the somatic number of chromosomes is restored by fusion of the egg pronucleus with the polar body from the reduction division (Subbotin et al., 2021; Triantaphyllou, 1985).
Eggs were present throughout the year in a golf green sown with creeping bentgrass (Agrostis stolonifera var. stolonifera L). There was a high percentage hatch (46-88%) when eggs were incubated at 20◦C. Egg development and hatch ocurred at tempreatures between 15 and 25C and was very limited above and below that range, It was most rapid at 23C (7 days) and slower at 15C (17 days). (Morris et al., 2011).
Typical of the genus, the first-stage juvenile develops within the egg and molts to develop into the second stage. The second-stage juveniles (J2) are the infective stage that hatch from eggs and migrate through rhizosphere soil to host roots. The J2s penetrate the host roots and establish a specialized giant cell feeding site. They become sedentary while feeding from the giant cell(s), increase in size, and undergoing two more molts of non- feeding stages before developing into mature adult females or vermiform males.
The giant-cell feeding site is created when the nematode injects secretory proteins that stimulate changes in the plant cells. The cells become multinucleate and undergo nuclear division without cell wall formation. Giant cells can be very large and act as significant nutrient sinks, producing large amounts of proteins that the nematodes can use. Increases in the production of plant growth regulators from nematode feeding also play a role in this increase in cell size and division. Root cells around the giant cells enlarge and divide rapidly, resulting in gall formation. Once a female establishes a feeding site as a juvenile, she permanently remains within the plant root, exuding eggs into a gelatinous egg mass on the root surface (Martin, 2024; Perry and Moens, 2013).
Causes yellow-patches within a few years after new greens have been established (Elling, 2013; Morris et al., 2011).
Symptoms on potato are very similar to those of M. chitwoodi and M. fallax, i.e., small galls in roots and pimple-like swellings on the surface of potato tubers. However, M. fallax did not reduce yield or quality on two potato cultivars tested in the Netherlands (Elling, 2013).
Host Plant Resistance, Non-hosts and Crop Rotation alternatives:
Elling, A.A. 2013. Major Emerging Problems with Minor Meloidogyne Species. Phytopathology 103:1092-1102.
Karssen, G., Bolk, R. J., Van Aelst, A. C., Van Den Beld, I., Kox, L. F. F., Korthals, G., Molendijk, L., Zijlstra, C., Van Hoof, R., and Cook, R. 2004. Description of Meloidogyne minor n. sp. (Nematoda: Meloidogynidae), a root-knot nematode associated with yellow patch disease in golf courses. Nematology 6:59-72.
Martin, H.J. 2924. California Pest Rating Proposal for Meloidogyne minor Karssen et al. 2004. California Department of Food and Agriculture, Sacramento, California USA.
McClure, M. A., Nischwitz, C., Skantar, A. M., Schmitt, M. E., and Subbotin, S. A. 2012. Root-knot nematodes in golf course greens of the Western USA. Plant Dis. 96:635-647.
Morris, K.S., Horgan, F.G., Downes, M.J., Griffin, C.T. 2011. The effect of temperature on hatch and activity of second-stage juveniles of the root-knot nematode, Meloidogyne minor, an emerging pest in north-west Europe. Nematology 13:983-993.
Subbotin, S.A. Palomares-Rius, J.E., Castillo, P. 2021. Systematics of Root-knot Nematodes (Nematoda: Meloidogynidae). Nematology Monographs and Perspectives Vol 14: D.J. Hunt and R.N. Perry (eds) Brill, Leiden, The Netherlands 857p.
Triantaphyllou, A.C. 1985. Gametogenesis and the chromosomes of Meloidogune nataliei: not typical of other root-knot nematodes. J. Nematology 17:1-5.
Triantaphyllou, A.C. 1985. Cytogenetics, cytotaxonomy and phylogeny of root-knot nematodes. In Sasser, J.N. & Carter, C.C. (eds) An Advanced Treatiswe on Meloidogyne.Vol 1. Biology and Control.N.C. State Universty Graphics, Raleigh, N.C. USA.