scholarly journals Plants Specifically Modulate the Microbiome of Root-Lesion Nematodes in the Rhizosphere, Affecting Their Fitness

2021 ◽  
Vol 9 (4) ◽  
pp. 679
Author(s):  
Ahmed Elhady ◽  
Olivera Topalović ◽  
Holger Heuer
Keyword(s):  
Plant Species ◽  
Root Exudates ◽  
Plant Protection ◽  
Nematode Species ◽  
Soil Microbiome ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Ethiopian Mustard ◽  
Specific Subset ◽  
Plant Parasitic

Plant-parasitic nematodes are a major constraint on agricultural production. They significantly impede crop yield. To complete their parasitism, they need to locate, disguise, and interact with plant signals exuded in the rhizosphere of the host plant. A specific subset of the soil microbiome can attach to the surface of nematodes in a specific manner. We hypothesized that host plants recruit species of microbes as helpers against attacking nematode species, and that these helpers differ among plant species. We investigated to what extend the attached microbial species are determined by plant species, their root exudates, and how these microbes affect nematodes. We conditioned the soil microbiome in the rhizosphere of different plant species, then employed culture-independent and culture-dependent methods to study microbial attachment to the cuticle of the phytonematode Pratylenchus penetrans. Community fingerprints of nematode-attached fungi and bacteria showed that the plant species govern the microbiome associated with the nematode cuticle. Bacteria isolated from the cuticle belonged to Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Sphingobacteria, and Firmicutes. The isolates Microbacterium sp. i.14, Lysobacter capsici i.17, and Alcaligenes sp. i.37 showed the highest attachment rates to the cuticle. The isolates Bacillus cereus i.24 and L. capsici i.17 significantly antagonized P. penetrans after attachment. Significantly more bacteria attached to P. penetrans in microbiome suspensions from bulk soil or oat rhizosphere compared to Ethiopian mustard rhizosphere. However, the latter caused a better suppression of the nematode. Conditioning the cuticle of P. penetrans with root exudates significantly decreased the number of Microbacterium sp. i.14 attaching to the cuticle, suggesting induced changes of the cuticle structure. These findings will lead to a more knowledge-driven exploitation of microbial antagonists of plant-parasitic nematodes for plant protection.

scholarly journals Plants Specifically Modulate the Microbiome of Root-lesion Nematodes in the Rhizosphere, Affecting Their Fitness

2021 ◽  
Author(s):  
Ahmed Elhady ◽  
Olivera Topalović ◽  
Holger Heuer
Keyword(s):  
Plant Species ◽  
Root Exudates ◽  
Plant Protection ◽  
Nematode Species ◽  
Soil Microbiome ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Ethiopian Mustard ◽  
Specific Subset ◽  
Plant Parasitic

Plant-parasitic nematodes are a major constraint for agricultural production. They significantly impede crop yield. To complete their parasitism, they need to locate, disguise, and interact with plant signals exuded in the rhizosphere of the host plant. A specific subset of the soil microbiome can attach to the surface of nematodes in a specific manner. We hypothesized that host plants recruit species of microbes as helpers against attacking nematode species, and that these helpers differ among plant species. We investigated to what extend the attached microbial species are determined by plant species, their root exudates, and how these microbes affect nematodes. We conditioned the soil microbiome in the rhizosphere of different plant species, then employed culture-independent and culture-dependent methods to study the microbial attachment to the cuticle of the phytonematode Pratylenchus penetrans. Community fingerprints of nematode-attached fungi and bacteria showed that the plant species govern the microbiome associated with nematode cuticle. Bacteria isolated from the cuticle belonged to Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Sphingobacteria, and Firmicutes. The isolates Microbacterium sp. i.14, Lysobacter capsici i.17, and Alcaligenes sp. i.37 showed the highest attachment rates to the cuticle. The isolates Bacillus cereus i.24 and L. capsici i.17 significantly antagonized P. penetrans after attachment. Significantly more bacteria attached to P. penetrans in microbiome suspensions from bulk soil or oat rhizosphere compared to Ethiopian mustard rhizosphere. However, the latter caused a better suppression of the nematode. Conditioning the cuticle of P. penetrans with root exudates significantly decreased the number of Microbacterium sp. i.14 attaching to the cuticle, suggesting induced changes of the cuticle structure. These findings will lead to a more knowledge-driven exploitation of microbial antagonists of plant-parasitic nematodes for plant protection.

scholarly journals New records of plant-parasitic nematodes from Iceland

Polar Biology ◽  
2020 ◽  
Vol 43 (10) ◽  
pp. 1655-1661
Author(s):  
Łukasz Flis ◽  
Franciszek Wojciech Kornobis ◽  
Magdalena Kubicz ◽  
Jón Guðmundsson
Keyword(s):  
New Records ◽  
Plant Protection ◽  
Nematode Species ◽  
First Record ◽  
Molecular Data ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
The Family ◽  
Nematode Biodiversity ◽  
Plant Parasitic

Abstract The plant-parasitic nematodes of Iceland are poorly understood. To address this, a study of the nematodes of the families Criconematidae and Hemicycliophoridae was performed in 2015. Soil samples were taken from underneath various host plants in different locations in Iceland. The identification was performed on the basis of the general morphology and subsequently confirmed by molecular markers (D2-D3 28S rDNA). The study revealed the presence of nematode specimens belonging to four species of the family Criconematidae: Criconemoides amorphus, Criconema demani, Mesocriconema xenoplax and Mesocriconema curvatum, as well as one species Hemicycliophora conida of the family Hemicycliophoridae. To our knowledge, this is the first record of the occurrence of these nematode species in Iceland. The species identified are economically important plant-parasitic nematodes of likely interest to—among others—Icelandic plant protection professionals. This report broadens our knowledge of Iceland’s nematode biodiversity; moreover, morphological analyses and molecular data may contribute to better understanding the origin of nematode species on the island of Iceland.

scholarly journals Optimizing Safe Approaches to Manage Plant-Parasitic Nematodes

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1911
Author(s):  
Mahfouz M. M. Abd-Elgawad
Keyword(s):  
Crop Yields ◽  
Abiotic Factors ◽  
Alternative Methods ◽  
Soil Microbiome ◽  
Parasitic Nematodes ◽  
Control Mechanisms ◽  
Plant Parasitic Nematodes ◽  
Safe Alternative ◽  
Microbial Groups ◽  
Plant Parasitic

Plant-parasitic nematodes (PPNs) infect and cause substantial yield losses of many foods, feed, and fiber crops. Increasing concern over chemical nematicides has increased interest in safe alternative methods to minimize these losses. This review focuses on the use and potential of current methods such as biologicals, botanicals, non-host crops, and related rotations, as well as modern techniques against PPNs in sustainable agroecosystems. To evaluate their potential for control, this review offers overviews of their interactions with other biotic and abiotic factors from the standpoint of PPN management. The positive or negative roles of specific production practices are assessed in the context of integrated pest management. Examples are given to reinforce PPN control and increase crop yields via dual-purpose, sequential, and co-application of agricultural inputs. The involved PPN control mechanisms were reviewed with suggestions to optimize their gains. Using the biologicals would preferably be backed by agricultural conservation practices to face issues related to their reliability, inconsistency, and slow activity against PPNs. These practices may comprise offering supplementary resources, such as adequate organic matter, enhancing their habitat quality via specific soil amendments, and reducing or avoiding negative influences of pesticides. Soil microbiome and planted genotypes should be manipulated in specific nematode-suppressive soils to conserve native biologicals that serve to control PPNs. Culture-dependent techniques may be expanded to use promising microbial groups of the suppressive soils to recycle in their host populations. Other modern techniques for PPN control are discussed to maximize their efficient use.

scholarly journals Five Species of Plant Parasitic Nematodes (Order: Tylenchidae) Affecting Vegetable Crops of Nepal

2016 ◽  
Vol 10 (1) ◽  
pp. 10-14
Author(s):  
Arvind K. Keshari ◽  
Ranjana Gupta
Keyword(s):  
Life Sciences ◽  
Nematode Species ◽  
Parasitic Nematodes ◽  
Kathmandu Valley ◽  
Vegetable Crops ◽  
Plant Parasitic Nematodes ◽  
Morphometric Data ◽  
First Time ◽  
Plant Parasitic

During a survey for plant parasitic nematodes affecting various vegetable crops grown in three hilly districts surrounding Kathmandu Valley, Nepal, five species of order Tylenchidae are reported for the first time from Nepal.The nematode species are Hoplolaimus indicus, Tylenchorhynchus mashhoodi, Helicotylenchus incisus, Microposthonia paraxestis and Hemicriconemoides cocophilus.All the species are illustrated with line diagrams and described with their morphometric data along with localities and host plants.International Journal of Life Sciences 10 (1) : 2016; 10-16

scholarly journals Molecular Characterization and Phylogenetic Relationships of Plant-Parasitic Nematodes Associated with Turfgrasses in North Carolina and South Carolina, United States

Plant Disease ◽  
2015 ◽  
Vol 99 (7) ◽  
pp. 982-993 ◽  
Author(s):  
Yongsan Zeng ◽  
Weimin Ye ◽  
James Kerns ◽  
Lane Tredway ◽  
Samuel Martin ◽  
...  
Keyword(s):  
North Carolina ◽  
South Carolina ◽  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Parasitic Nematode ◽  
Nematode Species ◽  
Plant Parasitic Nematode ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Plant Parasitic

The near-full-length 18S ribosomal DNA (rDNA) gene and internal transcribed spacer 1 region were amplified and sequenced from 52 nematode populations belonging to 28 representative species in 13 families recovered from turfgrasses in North Carolina (38 populations) and South Carolina (14 populations). This study also included 13 nematode populations from eight other plant hosts from North Carolina for comparison. Nematodes were molecularly characterized and the phylogenetic relationships were explored based on 18S rDNA sequences. Phylogenetic analysis using Bayesian inference was performed using five groups of the plant-parasitic nematode populations Tylenchids, Criconematids, Longidorids, Xiphinematids, and Trichodorids. The 65 nematode populations were clustered correspondingly within appropriate positions of 13 families, including Belonolaimidae, Caloosiidae, Criconematidae, Dolichodoridae, Hemicycliophoridae, Hoplolaimidae, Heteroderidae, Longidoridae, Meloidogynidae, Paratylenchidae, Pratylenchidae, Telotylenchidae, and Trichodoridae. This study confirms previous morphological-based identification of the plant-parasitic nematode species found in turfgrasses and provides a framework for future studies of plant-parasitic nematodes associated with turfgrasses based upon DNA sequences and phylogenetic relationships.

scholarly journals Use of Entomopathogenic Nematodes and Thyme Oil to Suppress Plant-Parasitic Nematodes on English Boxwood

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Enrique E. Pérez ◽  
Edwin E. Lewis
Keyword(s):  
Population Growth ◽  
Entomopathogenic Nematodes ◽  
Parasitic Nematode ◽  
Nematode Species ◽  
Plant Parasitic Nematode ◽  
Nematode Population ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Thyme Oil ◽  
Plant Parasitic

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.

scholarly journals PLANT PARASITIC NEMATODES ASSOCIATED WITH RABBITEYE, SOUTHERN HIGHBUSH AND HIGHBUSH BLUEBERRIES

HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 264D-264
Author(s):  
John R. Clark ◽  
Robert Robbins
Keyword(s):  
Parasitic Nematode ◽  
Nematode Species ◽  
Vaccinium Corymbosum ◽  
Parasitic Nematodes ◽  
Small Populations ◽  
Plant Parasitic Nematodes ◽  
Total Plant ◽  
Highbush Blueberries ◽  
Southern Highbush ◽  
Plant Parasitic

Two replicated blueberry plantings, one containing one highbush, (Vaccinium corymbosum) two southern highbush and two rabbiteye (V.ashei) cultivars, and another containing one highbush and three rabbiteye cultivars were sampled in October, 1991 and plant parasitic nematodes extracted and counted. Additionally, 15 commercial rabbiteye plantings were sampled. Standard and southern highbush samples had total plant parasitic nematode levels of 228-451 nematodes/250 ml soil compared to 4-14 nematodes/250 ml soil for rabbiteye. No difference in nematode population was found among the standard highbush ('Bluecrop') and southern highbush ('Cooper', 'Gulfcoast') cultivars. Xiphinema americanum was the most common nematode species found, along with very small populations of Paratrichodorus minor. All commercial plantings had lower nematode levels in samples from the blueberry plants as compared to those from the sod middles between the rows. Nematode levels from commercial plantings ranged from 1477/250ml soil from blueberry plants and 11-1546/250 ml soil from the sod middles. Species found at high levels in the sod samples were usually distinctly different from those found associated with the blueberry plants.

scholarly journals Community Analysis of Nematodes Associated with Banana, Identification of root knot nematode and Evaluation the Susceptibility of Some Cultivars to Infection

2021 ◽  
Author(s):  
Radwa G. Mostafa ◽  
Aida M. El-Zawahry ◽  
Ashraf E. M. Khalil ◽  
Ameer E. Elfarash ◽  
Ali D. A. Allam
Keyword(s):  
Meloidogyne Javanica ◽  
Nematode Species ◽  
Common Species ◽  
Molecular Techniques ◽  
Control Measures ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Plant Parasitic

Abstract Background Plant-parasitic nematodes are extremely dangerous pests in a variety of economically important crops. The purpose of this study was a survey of all nematode species existing in banana from three sites in Assiut Governorate, Egypt and to characterize the most common species by morphological, morphometric and molecular techniques (PCR with species-specific primers). Then, study of resistance or sensitivity of some banana cultivars to root-knot nematodes.Methods and Results Four nematodes, Meloidogyne, Rotylenchulus reniformis, Helicotylenchus and Pratylenchus were isolated and identified from soil and root samples collected from banana plants. Most frequently occurring of plant parasitic nematode species in banana was Meloidogyne. Former research found differences in species and in resistance to root-knot nematodes among the examined plant cultivars. Identification of Root-knot nematodes by Characterize of morphometric, molecularly, morphological isolate of Meloidogyne related to banana plants. The results revealed that the identified nematode species, Meloidogyne javanica, is the most common plant-parasitic nematodes in all locations. Data on the susceptibility of the tested banana cultivars to M. javanica revealed that Grand Naine was highly susceptible (HS) however, Magraby was susceptible (S) but Williams and Hindi cultivars were moderately resistant (MR).Conclusions we concluded that a survey revealed the significant prevalence of Meloidogyne javanica, the most important nematodes on banana in Assiut. The morphometric, morphological, and molecular identification were harmonic with one another. In addition to the host response of certain banana cultivars, to M. javanica that resistance is of significance and can be helpful to incorporate through planning control measures for root- knot nematodes.

scholarly journals Description of two new Ogma Southern, 1914 species (Nemata: Criconematoidea) with a list of plant-parasitic nematode species from Natal

Koedoe ◽  
1992 ◽  
Vol 35 (1) ◽  
Author(s):  
Esther Van den Berg
Keyword(s):  
National Park ◽  
Nature Reserve ◽  
Parasitic Nematode ◽  
Nematode Species ◽  
Plant Parasitic Nematode ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Tail Tip ◽  
Plant Parasitic

Two new O^nia Southern, 1914 species are described and figured from Giant's Castle Nature Reserve, Kamberg Nature Reserve and the Royal Natal National Park. O^ma naomiae spec. nov. females are characterised by having 10 to 12 longitudinal rows of scales on 63 to 69 retrorse body annuli; scales haphazardly arranged on first nine to 10 annuli; scales mostly with two projections, becoming longer toward tail end; all scales with minute protuberances on outer edges; lip region with one annulus with a greater diameter than first body annulus. Juveniles with 14 to 16 longitudinal rows of scales on 73 to 76 retrorse body annuli; each scale bearing five to seven sharply pointed processes; one lip annulus with an equal diameter to first body annulus. O^ma ueckermanni spec. nov. females are characterised by eight longitudinal rows of rounded scales on 60 to 67 body annuli becoming longer toward tail tip where they bear two, three or four-pronged processes; roughly sculptured recessed part of annulus extends to follow the outline of the scale almost forming a pillar between two succeeding scales; one lip annulus with a greater diameter than first body annulus; raised labial area with six pseudolips and no submedian lobes; margin of lip annulus with rounded tooth-like projections; stylet 49,3 to 60,7 ^m long. A list is given of the 16 known plant-parasitic nematodes found in these areas.

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