THE ROOT-LESION NEMATODE, PRATYLENCHUS PENETRANS (COBB, 1917) FILIP. & STEK., 1941, IN STRAWBERRY IN THE NIAGARA PENINSULA AND NORFOLK COUNTY IN ONTARIO

1962 ◽  
Vol 42 (4) ◽  
pp. 728-736 ◽  
Author(s):  
J. L. Townshend

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.

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Paulo Vieira ◽  
Jonathan Shao ◽  
Paramasivan Vijayapalani ◽  
Thomas R. Maier ◽  
Clement Pellegrin ◽  
...  

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Selamawit A. Kidane ◽  
Solveig Haukeland ◽  
Beira H. Meressa ◽  
Anne Kathrine Hvoslef-Eide ◽  
Danny L. Coyne

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.


2011 ◽  
Vol 12 (1) ◽  
pp. 2 ◽  
Author(s):  
Gregory L. Tylka ◽  
Adam J. Sisson ◽  
Laura C. Jesse ◽  
John Kennicker ◽  
Christopher C. Marett

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.


1997 ◽  
Vol 37 (1) ◽  
pp. 75 ◽  
Author(s):  
L. J. McLeish ◽  
G. N. Berg ◽  
J. M. Hinch ◽  
L. V. Nambiar ◽  
M. R. Norton

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.


1962 ◽  
Vol 42 (2) ◽  
pp. 314-322 ◽  
Author(s):  
J. L. Townshend

Pratylenchus penetrans, Meloidogyne hapla, and Paratylenchus hamatus were the predominant nematode species associated with the roots of celery in the Burlington area of Ontario. Pratylenchus penetrans was found associated with irregular areas of stunted celery and because of the orange color of the roots the growers called the condition "rusty" root. In growth room studies relatively large numbers of P. penetrans were required to produce stunting. The amount of growth was inversely proportional to the size of the initial nematode population. Pratylenchus penetrans can overwinter in celery root debris. Tomato, cabbage, lettuce, cauliflower, potato, and eggplant were also found to be hosts of P. penetrans.


2007 ◽  
Vol 47 (5) ◽  
pp. 620 ◽  
Author(s):  
B. L. Blair ◽  
G. R. Stirling

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.


Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Enrique E. Pérez ◽  
Edwin E. Lewis

A 2-year experiment was conducted to test suppression of plant-parasitic nematodes on English boxwood using entomopathogenic nematodes and 3.5% thyme oil formulated as Promax. Treatments were Steinernema riobrave formulated as BioVector and S. feltiae formulated as Nemasys, both applied at a rate of 2.5 billion infective juveniles/ha, thyme oil at rate of 9.3 liters/ha, and nontreated control. In the 2001 season, treatment with S. feltiae reduced (P ≤ 0.05) the population growth of Tylenchorhynchus sp. 7 days after treatment and Hoplolaimus sp. 30 and 60 days after treatment. Treatment with S. riobrave reduced (P ≤ 0.05) the population growth of all plant-parasitic nematode species at all sampling dates, with the exception of Mesocriconema sp. 30 days after treatment and Tylenchorhynchus sp. and Rotylenchus buxophilus 60 days after treatment. Treatment with thyme oil reduced (P ≤ 0.05) the population growth of all plant-parasitic nematode genera at all sampling dates except Tylenchorhynchus sp. and R. buxophilus 60 days after treatment. In the 2002 season, treatment with S. feltiae had no effect on nematode population growth. Treatment with S. riobrave reduced (P ≤ 0.05) the population growth of R. buxophilus 7 days after treatment, and all plant-parasitic nematodes 30 and 60 days after treatment except Hoplolaimus sp. 30 days after treatment and Mesocriconema sp. 60 days after treatment. Treatment with thyme oil reduced (P ≤ 0.05) the population growth at all sampling dates of plant-parasitic nematodes except Mesocriconema sp. 60 days after treatment.


2020 ◽  
Vol 9 (1) ◽  
pp. 43-49
Author(s):  
Timothy I. Olabiyi ◽  
Samuel O. Akinrinola ◽  
Olajumoke E. Ayanda

Three different plant extracts (Khaya ivorensis, Azadirachta indica and Daniella oleifera) and two Trichoderma species (T. harzianum and T. atroviride), singly and in combination, were assessed on nematode population changes and also in the control of plant parasitic nematodes on tomato under field condition during 2018 and 2019 planting seasons. During each trial, plant parasitic nematodes encountered in the field were Meloidogyne, Pratylenchus, Xiphinema and Helicotylenchus species. The experiment was a randomized complete block design with 4 x 3 factorial scheme and five replications. Factor A being plant extracts (Khaya ivorensis, Azadirachta indica, Daniella oleifera) and control, and factor B being bio-control agents (Trichoderma harzianum, T. atroviride) and control, resulting in 12 treatments. Significant reductions were observed on the population of the plant parasitic nematodes at all treatment levels with neem plant extract, in combination with either T. harzianum or T. atroviride resulted in the greatest significant decrease. Applications of different plant extracts and Trichoderma species, singly and in combination, enhanced the growth and yield of tomato infected with parasitic nematodes.


Author(s):  
Rosa H. Manzanilla-López ◽  
Ralf-Udo Ehlers

Abstract A nematological culture is a method of multiplying nematodes by enabling them to reproduce and increase in a culture medium or a specific host under controlled conditions. This chapter presents culturing techniques, focused mainly on plant-parasitic nematodes and entomopathogenic nematodes, with some mention of soil free-living nematodes.


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