Plant-parasitic nematodes in vegetable fields in Oita Prefecture and damage to Japanese radish caused by root-lesion nematode, Pratylenchus penetrans.

Pratylenchus penetrans (Cobb, 1917) Filip. & Stek., 1941, and Paratylenchus projectus Jenkins, 1956, were the predominant plant parasitic nematodes associated with strawberry in the Niagara Peninsula and Norfolk County in Ontario from 1956 to 1960. However, P. penetrans was the only nematode whose occurrence could be correlated with a specific type of root lesion and with stunting. The lesions it caused on the roots were elliptical and amber to dark brown. All strawberry varieties examined were infected with P. penetrans. Under controlled conditions large numbers of P. penetrans were required to produce stunting. The amount of growth was inversely proportional to the density of the initial nematode population.

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A new esophageal gland transcriptome reveals signatures of large scale de novo effector birth in the root lesion nematode Pratylenchus penetrans

BMC Genomics ◽

10.1186/s12864-020-07146-0 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Paulo Vieira ◽

Jonathan Shao ◽

Paramasivan Vijayapalani ◽

Thomas R. Maier ◽

Clement Pellegrin ◽

...

Keyword(s):

Large Scale ◽

Molecular Mechanisms ◽

Parasitic Nematodes ◽

Gene Gain ◽

Pratylenchus Penetrans ◽

Root Lesion Nematode ◽

Plant Parasitic Nematodes ◽

Depth Analysis ◽

Lesion Nematode ◽

Plant Parasitic

Abstract Background The root lesion nematode Pratylenchus penetrans is a migratory plant-parasitic nematode responsible for economically important losses in a wide number of crops. Despite the importance of P. penetrans, the molecular mechanisms employed by this nematode to promote virulence remain largely unknown. Results Here we generated a new and comprehensive esophageal glands-specific transcriptome library for P. penetrans. In-depth analysis of this transcriptome enabled a robust identification of a catalogue of 30 new candidate effector genes, which were experimentally validated in the esophageal glands by in situ hybridization. We further validated the expression of a multifaceted network of candidate effectors during the interaction with different plants. To advance our understanding of the “effectorome” of P. penetrans, we adopted a phylogenetic approach and compared the expanded effector repertoire of P. penetrans to the genome/transcriptome of other nematode species with similar or contrasting parasitism strategies. Our data allowed us to infer plausible evolutionary histories that shaped the effector repertoire of P. penetrans, as well as other close and distant plant-parasitic nematodes. Two remarkable trends were apparent: 1) large scale effector birth in the Pratylenchidae in general and P. penetrans in particular, and 2) large scale effector death in sedentary (endo) plant-parasitic nematodes. Conclusions Our study doubles the number of validated Pratylenchus penetrans effectors reported in the literature. The dramatic effector gene gain in P. penetrans could be related to the remarkable ability of this nematode to parasitize a large number of plants. Our data provide valuable insights into nematode parasitism and contribute towards basic understating of the adaptation of P. penetrans and other root lesion nematodes to specific host plants.

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Planting Material of Enset (Ensete ventricosum), a Key Food Security Crop in Southwest Ethiopia, Is a Key Element in the Dissemination of Plant-Parasitic Nematode Infection

Frontiers in Plant Science ◽

10.3389/fpls.2021.664155 ◽

2021 ◽

Vol 12 ◽

Author(s):

Selamawit A. Kidane ◽

Solveig Haukeland ◽

Beira H. Meressa ◽

Anne Kathrine Hvoslef-Eide ◽

Danny L. Coyne

Keyword(s):

Food Security ◽

Nematode Infection ◽

Parasitic Nematodes ◽

Herbaceous Plant ◽

Root Lesion Nematode ◽

Plant Parasitic Nematodes ◽

Ensete Ventricosum ◽

Planting Material ◽

Lesion Nematode ◽

Plant Parasitic

Enset (Ensete ventricosum), is a perennial herbaceous plant belonging to the family Musaceae, along with banana and plantain. Despite wild populations occurring in eastern, central and southern Africa, it is only in Ethiopia that the crop has been domesticated, where it is culturally and agriculturally symbolic as a food security crop. Although an under-researched orphan crop, enset serves as a staple food for about 20% of the Ethiopian population, comprising more than 20 million people, demonstrating its value in the country. Similar to banana and plantain, enset is heavily affected by plant-parasitic nematodes, with recent studies indicating record levels of infection by the root lesion nematode Pratylenchus goodeyi. Enset is propagated vegetatively using suckers that are purposely initiated from the mother corm. However, while banana and plantain suckers have proven to be a key source of nematode infection and spread, knowledge on the infection levels and role of enset suckers in nematode dissemination is lacking. Given the high levels of plant-parasitic nematodes reported in previous surveys, it is therefore speculated that planting material may act as a key source of nematode dissemination. To address this lack of information, we assessed enset planting material in four key enset growing zones in Ethiopia. A total of 340 enset sucker samples were collected from farmers and markets and analyzed for the presence of nematodes. Nematodes were extracted using a modified Baermann method over a period of 48 h. The root lesion nematode P. goodeyi was present in 100% of the samples, at various levels of infection. These conclusive results show that planting material is indeed a key source of nematode infection in enset, hence measures taken to ensure clean suckers for planting will certainly mitigate nematode infection and spread. The effect of nematode infection on yield and quality on enset remains to be investigated and would be a way forward to complement the nematode/disease studies conducted so far and add valuable knowledge to the current poorly known impact of pests and diseases.

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Testing for Plant-parasitic Nematodes that Feed on Corn in Iowa 2000-2010

Plant Health Progress ◽

10.1094/php-2011-1205-01-rs ◽

2011 ◽

Vol 12 (1) ◽

pp. 2 ◽

Cited By ~ 8

Author(s):

Gregory L. Tylka ◽

Adam J. Sisson ◽

Laura C. Jesse ◽

John Kennicker ◽

Christopher C. Marett

Keyword(s):

Sampling Time ◽

Parasitic Nematodes ◽

State University ◽

Root Lesion Nematode ◽

Plant Parasitic Nematodes ◽

Iowa State University ◽

Population Densities ◽

The Past ◽

Lesion Nematode ◽

Plant Parasitic

The Iowa State University Plant and Insect Diagnostic Clinic analyzes soil and root samples for plant-parasitic nematodes. The results of samples associated with corn that were submitted from 2000 through 2010 were summarized. One or more genera of plant-parasitic nematodes were found in 92% of the samples. Spiral nematode and root-lesion nematode were most commonly found. Other nematodes recovered were dagger, lance, needle, pin, ring, and stunt nematodes. Nematodes recovered at damaging population densities were dagger, needle, ring, and spiral nematodes. An average of 15 samples were submitted per year from 2000 to 2004. Sample numbers increased nearly threefold since 2005, but overall sample numbers were low every year from 2000 through 2010. Samples were received from 53 of the 99 Iowa counties, and most samples were received in June and July, which is the recommended sampling time. Nematodes that have been associated with corn in Iowa in the past that were not recovered from the samples were sheath, sting, and stubby-root nematodes. The methods used to extract the nematodes from soil and roots and how the samples were handled during collection and processing may have affected the species and population densities recovered. Much more frequent and widespread sampling is needed in Iowa for plant-parasitic nematodes that feed on corn. Accepted for publication 28 October 2011. Published 5 December 2011.

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Plant parasitic nematodes in white clover and soil from white clover pastures in Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea96046 ◽

1997 ◽

Vol 37 (1) ◽

pp. 75 ◽

Cited By ~ 8

Author(s):

L. J. McLeish ◽

G. N. Berg ◽

J. M. Hinch ◽

L. V. Nambiar ◽

M. R. Norton

Keyword(s):

White Clover ◽

Parasitic Nematode ◽

Cyst Nematode ◽

Parasitic Nematodes ◽

Root Lesion Nematode ◽

Plant Parasitic Nematodes ◽

Meloidogyne Spp ◽

Trifolium Repens L ◽

Lesion Nematode ◽

Plant Parasitic

Summary. Seventeen sites, including locations in all the major white clover growing regions of Australia, were surveyed for the presence of plant parasitic nematodes in autumn and spring 1993. Trifolium repens L. cvv. Haifa and Irrigation, plus 1 other cultivar, were sampled at each site and nematodes extracted from roots, stems and soil. Thirteen genera of plant parasitic nematodes were detected. The clover cyst nematode, Heterodera trifolii, and root knot nematodes, Meloidogyne spp., were each recorded at over 75% of the sites. The most common genera of plant parasitic nematodes detected were Tylenchus, which was present at all sites, and Pratylenchus (root lesion nematode), which was present at all but 1 site. Other plant parasitic nematode genera found included Ditylenchus, Helicotylenchus and Paratylenchus. The widespread presence of nematodes in white clover pastures, and the high populations at some sites, suggest that they may be economically important to the Australian dairy industry.

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The role of plant-parasitic nematodes in reducing yield of sugarcane in fine-textured soils in Queensland, Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea05287 ◽

2007 ◽

Vol 47 (5) ◽

pp. 620 ◽

Cited By ~ 22

Author(s):

B. L. Blair ◽

G. R. Stirling

Keyword(s):

Growth And Yield ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Population Densities ◽

Lesion Nematode ◽

Yield Responses ◽

The Impact ◽

Stalk Length ◽

Plant Parasitic

Damage to sugarcane caused by root-knot nematode (Meloidogyne spp.) is well documented in infertile coarse-textured soils, but crop losses have never been assessed in the fine-textured soils on which more than 95% of Australia’s sugarcane is grown. The impact of nematodes in these more fertile soils was assessed by repeatedly applying nematicides (aldicarb and fenamiphos) to plant and ratoon crops in 16 fields, and measuring their effects on nematode populations, sugarcane growth and yield. In untreated plant crops, mid-season population densities of lesion nematode (Pratylenchus zeae), root-knot nematode (M. javanica), stunt nematode (Tylenchorhynchus annulatus), spiral nematode (Helicotylenchus dihystera) and stubby-root nematode (Paratrichodorus minor) averaged 1065, 214, 535, 217 and 103 nematodes/200 mL soil, respectively. Lower mean nematode population densities were recorded in the first ratoon, particularly for root-knot nematode. Nematicides reduced populations of lesion nematode by 66–99% in both plant and ratoon crops, but control of root-knot nematode was inconsistent, particularly in ratoons. Nematicide treatment had a greater impact on shoot and stalk length than on shoot and stalk number. The entire community of pest nematodes appeared to be contributing to lost productivity, but stalk length and final yield responses correlated most consistently with the number of lesion nematodes controlled. Fine roots in nematicide-treated plots were healthier and more numerous than in untreated plots, and this was indicative of the reduced impact of lesion nematode. Yield responses averaged 15.3% in plant crops and 11.6% in ratoons, indicating that nematodes are subtle but significant pests of sugarcane in fine-textured soils. On the basis of these results, plant-parasitic nematodes are conservatively estimated to cost the Australian sugar industry about AU$82 million/annum.

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Root parasitic nematodes in nursery plants imported to Finland in 1980

Agricultural and Food Science ◽

10.23986/afsci.72197 ◽

1985 ◽

Vol 57 (3) ◽

pp. 155-162

Author(s):

Sirpa Kurppa

Keyword(s):

Infected Plant ◽

Virus Transmission ◽

Parasitic Nematodes ◽

Pratylenchus Penetrans ◽

Root Lesion Nematode ◽

Root Knot Nematode ◽

Meloidogyne Spp ◽

Lesion Nematode ◽

De Man ◽

Ditylenchus Destructor

Injurious nematodes were found in 201 of the investigated 670 plant stocks of 42 imported consignments. Infections by quarantine nematodes appeared in 100 stocks of 26 consignments, 15 there of including 3 or more infected plant stocks each. Root knot nematode, Meloidogyne spp., appeared in 81 stocks, i.e. 12 % of the investigated material. The infections were found in 40 plant species, relatively often in barberry, Berberis sp., and in peony, Paeonia sp.. Among garden roses, 26 out of 167 stocks investigated were infected by root knot nematodes. Root lesion nematode, Pratylenchus penetrans (Cobb) Chitwood & Oteifa, of P. convallariae Seinhorst was found in 28 plant stocks, i.e. 4 % of the investigated material. Several Pratylenchus-infected stocks were found among roses, raspberry and barberry. Potato rot nematode, Ditylenchus destructor Thorne, was found in one rose stock and related D. myceliophagus J. B. Goodey in 12 stocks of various plants. Several ectoparasitic species were found in very low numbers. Virus vectors, Trichodorus primitivus (de Man) Micoletzky and T. viruliferus Hooper, were detected in a total of four stocks, but too few for virus transmission tests. The transmissability ofthe detected nematodes was discussed, and the risks of introduction of nematode pests to the country was re-assessed.

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Occurrence of plant-parasitic nematodes on enset (Ensete ventricosum) in Ethiopia with focus on Pratylenchus goodeyi as a key species of the crop

Nematology ◽

10.1163/15685411-bja10058 ◽

2020 ◽

pp. 1-13

Author(s):

Selamawit A. Kidane ◽

Beira H. Meressa ◽

Solveig Haukeland ◽

Trine Hvoslef-Eide ◽

Christer Magnusson ◽

...

Keyword(s):

Population Density ◽

Molecular Data ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Ensete Ventricosum ◽

Mountainous Regions ◽

Southwestern Ethiopia ◽

Key Species ◽

Lesion Nematode ◽

Plant Parasitic

Summary Enset (Ensete ventricosum) is an important starch staple crop, cultivated primarily in south and southwestern Ethiopia. Enset is the main crop of a sustainable indigenous African system that ensures food security in a country that is food deficient. Related to the banana family, enset is similarly affected by plant-parasitic nematodes. Plant-parasitic nematodes impose a huge constraint on agriculture. The distribution, population density and incidence of plant-parasitic nematodes of enset was determined during August 2018. A total of 308 fields were sampled from major enset-growing zones of Ethiopia. Eleven plant-parasitic nematode taxa were identified, with Pratylenchus (lesion nematode) being the most prominent genus present with a prominence value of 1460. It was present in each sample, with a highest mean population density per growing zone of 16 050 (10 g root)−1, although densities as high as 25 000 were observed in fields at higher altitudes in Guraghe (2200-3000 m a.s.l.). This lesion nematode is found in abundance in the cooler mountainous regions. Visible damage on the roots and corms was manifested as dark purple lesions. Using a combination of morphometric and molecular data, all populations were identified as P. goodeyi and similar to populations from Kenya, Uganda and Spain (Tenerife). Differences in population densities amongst cultivars indicate possible resistance of enset to P. goodeyi.

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Spatial and spatiotemporal analysis of Meloidogyne hapla and Pratylenchus penetrans populations in commercial potato fields in New York, USA

Nematology ◽

10.1163/15685411-bja10034 ◽

2020 ◽

pp. 1-13

Author(s):

Adrienne M. Gorny ◽

Frank S. Hay ◽

Paul Esker ◽

Sarah J. Pethybridge

Keyword(s):

New York ◽

Spatiotemporal Analysis ◽

Parasitic Nematodes ◽

Meloidogyne Hapla ◽

Pratylenchus Penetrans ◽

Plant Parasitic Nematodes ◽

Population Densities ◽

Semivariogram Analysis ◽

Commercial Potato ◽

Plant Parasitic

Summary Meloidogyne hapla and Pratylenchus penetrans are important plant-parasitic nematodes affecting potato in New York and the Northeastern United States, yet little is known of their spatial patterns and spatiotemporal dynamics. Spatial patterns of M. hapla and Pratylenchus spp. were quantified using semivariogram analysis and Spatial Analysis by Distance IndicEs (SADIE). Nematode populations were assessed within each of three commercial potato fields in 2016 and 2017, with fields sampled on two occasions in-season. Semivariogram analysis and ordinary kriging indicated initial population densities to be spatially dependent over an average range of 110 m for M. hapla and 147 m for Pratylenchus spp. SADIE indicated Pratylenchus spp. to be significantly aggregated in nearly all fields (10 of 12 samplings, to 2.113). Meloidogyne hapla populations were aggregated in only three of 12 samplings ( to 1.738). Spatiotemporal analysis using the association function of SADIE indicated a strong and significant association between initial and final population densities of M. hapla and Pratylenchus spp. within fields. This information is fundamental for the development of enhanced sampling protocols for estimation of plant-parasitic nematodes and evaluating the feasibility of site-specific nematicide application in New York potato fields.

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Nematode Management in the Strawberry Fields of Southern Spain

Agronomy ◽

10.3390/agronomy9050252 ◽

2019 ◽

Vol 9 (5) ◽

pp. 252 ◽

Cited By ~ 2

Author(s):

Miguel Talavera ◽

Luis Miranda ◽

José Antonio Gómez-Mora ◽

María Dolores Vela ◽

Soledad Verdejo-Lucas

Keyword(s):

Tolerance Limit ◽

Southern Spain ◽

Parasitic Nematodes ◽

Soil Nematode ◽

Pratylenchus Penetrans ◽

Plant Parasitic Nematodes ◽

Population Densities ◽

The Impact ◽

Plant Parasitic ◽

Strawberry Cultivars

(1) Background: Spain is the sixth strawberry producer in the world, with about 6500 ha producing more than 350,000 tons, and an annual commercial value about 390 million €. Stunted and dead strawberry plants are frequently associated with plant-parasitic nematodes, but nematode diseases have not been characterized to date in the country. (2) Methods: A poll on the perception of the impact of nematodes on strawberry production was carried out by face-to-face interviews with farm advisors. In addition, nematological field surveys were carried out at the end of the growing season in 2017 and 2018 to determine prevalence and abundance of plant-parasitic nematodes in strawberry crops. The host suitability to Meloidogyne hapla of seventeen strawberry cultivars and the tolerance limit to M. hapla at progressively higher initial population densities (Pi) were assessed in pot experiments in a growth chamber. Comparison of the relative efficacies of several soil disinfestation methods in controlling nematode populations (M. hapla and Pratylenchus penetrans) was carried out in experimental field trials for twelve consecutive years. (3) Results: Meloidogyne spp., Pratylenchus penetrans, and Hemicycliophora spp. were the main plant-parasitic nematodes in the strawberry fields in South Spain. Root-knot nematodes were found in 90% of the fields, being M. hapla the most prevalent species (71% of the fields). A tolerance limit of 0.2 M. hapla juveniles per g of soil was estimated for strawberry, and currently cropped strawberry cultivars did not show resistance to M. hapla. Nematode population densities were reduced by more than 70% by soil fumigation with 1,3-dichloropropene, dazomet, dimethyl-disulfide, and methyl iodide. The efficacy of metam-sodium in reducing nematode populations was about 50% and that of chloropicrin, furfural, and sodium-azide, less than 40%. Combination of solarization with organic manures (biosolarization) reduced soil nematode populations by 68–73%. (4) Conclusions: Plant-parasitic nematodes (Meloidogyne, Pratylenchus, and Hemicycliophora) are widely distributed in the strawberry fields of Southern Spain. Strawberry is a poor host for M. hapla with a tolerance limit of 0.2 J2 per g of soil, and low population increases in cropping cycles of 7–8 months. Strawberry cultivars show a range of susceptibility and tolerance to M. hapla, but no resistance is found. Nematodes are effectively controlled by chemical fumigation of soils, but soil biosolarization is equally effective, and therefore, can be proposed as a sustainable alternative for pathogen control in strawberry cultivation.

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