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

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.

2021 ◽  
Vol 9 (4) ◽  
pp. 679
Author(s):  
Ahmed Elhady ◽  
Olivera Topalović ◽  
Holger Heuer

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.


2019 ◽  
Vol 12 (2) ◽  
pp. 97-107
Author(s):  
P. Eisvand ◽  
R. Farrokhi Nejad ◽  
S. Azimi

Summary During a survey on the biodiversity of plant-parasitic nematodes in citrus orchards of Khuzestan province (Southwestern Iran), 97 root and soil samples were collected. Nematodes were extracted and identified using morphological and morphometric diagnostic characters. Six nematode species were identified, namely: Helicotylenchus abunaamai, H. crenacauda, Pratylenchus allius, P. musii, Psilenchus hilarulus and Tylenchulus semipenetrans. Except T. semipenetrans, the remaining five species were found only in the rhizosphere of citrus, not in citrus roots, and their pathogenicity on citrus plants was not further studied. This is the first record of P. allius and P. musii for the nematode fauna in Iran. H. crenacauda is a new record for the nematode fauna in the Khuzestan province and is reported for the first time in citrus orchards in Iran. To our knowledge, this is the first report of H. abunaamai in citrus orchards worldwide.


Zootaxa ◽  
2019 ◽  
Vol 4545 (2) ◽  
pp. 205
Author(s):  
REZA GHADERI ◽  
AKBAR KAREGAR ◽  
ESMAEIL MIRAEIZ ◽  
ABBAS MOKARAM HESAR

The list of plant parasitic nematodes of the family Tylenchulidae, collected from Iran, is updated. Forty-one species belonging to five genera and three subfamilies are included in the list. Data for seven species of Paratylenchus are added, of which two species—P. perminimus and P. salubris—are new records for the Iranian nematofauna. The list of species, further information on their morphometrics, references to full or partial descriptions, associated plants, geographical distribution and some taxonomic remarks are provided. More detailed studies on some doubtful populations are added. Information on the taxonomic position of species in different classification schemes, as well as the preferences of some species for certain climatic conditions or ecological niches is provided. 


Genome ◽  
2020 ◽  
pp. 1-10
Author(s):  
Thomas O. Powers ◽  
Timothy S. Harris ◽  
Rebecca S. Higgins ◽  
Peter G. Mullin ◽  
Kirsten S. Powers

Nematodes are frequently cited as underrepresented in faunistic surveys using DNA barcoding with COI. This underrepresentation is generally attributed to a limited presence of nematodes in DNA databases which, in turn, is often ascribed to structural variability and high evolutionary rates in nematode mitochondrial genomes. Empirical evidence, however, indicates that many taxa are readily amplified with primer sets specifically targeted to different nematode families. Here we report the development of a COI reference library of 1726 specimens in the terrestrial plant parasitic nematode superfamily Criconematoidea. Specimens collected during an ecoregion survey of North America were individually photographed, measured, and PCR amplified to produce a 721 bp region of COI for taxonomic analysis. A neighbor-joining tree structured the dataset into 179 haplotype groups that generally conformed to morphospecies in traditional analysis or Barcode Index Numbers (BINs) in the BOLD system, although absent formal BIN membership due to insufficient overlap with the Folmer region of COI. Approximately one-third of the haplotype groups could be associated with previously described species. The geographic distribution of criconematid nematode species suggests a structure influenced by the major habitat types in the United States and Canada. All sequences collected in the ecoregion survey are deposited in BOLD.


2021 ◽  
Vol 39 (1) ◽  
pp. 14-21
Author(s):  
Saher Mohamad Al-Halabi ◽  
◽  
Khaled Al-Assas ◽  

Al-Halabi, S.M. and K. Al-Assas. 2021. Survey of Parasitic Nematode Genera Associated with Grapevine Roots in Sweida Governorate, Syria. Arab Journal of Plant Protection, 39(1): 14-21. The aim of this investigation was to survey the nematodes genera associated with the grapevine roots in Sweida Governorate, Syria. Samples were collected from vineyards of several main regions known for grape production (Massad, Al-Raha, Al-Kafer, Risas, Al-Quraya, Kanawat, and Ain Al-Arab in Dahr El-Jabal). The survey results confirmed the occurrence of the following plant-parasitic nematodes genera: Xiphinema, Meloidogyne, Pratylenchus, Paratylenchus, Helicotylenchus, Tylenchorynchus, Tylenchus and Ditylenchus in all investigated regions with high absolute frequency of 72.13, 73.77, 93.44, 96.72, 90.16, 93.44, 90.16 and 88.44%, respectively. The only exception was the genus Longidorus, which was limited with an absolute occurrence of 37.70%. Furthermore, this is the first record of these genera in Sweida Governorate. The results also revealed the presence of other genera of fungivore nematodes Aphelenchus and Aphelenchoides in all examined sites with 100% frequency. Keywords: Survey, classification, grapevine, nematodes, rhizosphere, Sweida, Syria


Author(s):  
Ahmed Elhady ◽  
Olivera Topalović ◽  
Holger Heuer

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.


2016 ◽  
Vol 40 ◽  
pp. 601-607 ◽  
Author(s):  
Somaye ALVANI ◽  
Esmat MAHDIKHANI-MOGHADAM ◽  
Hamid ROUHANI ◽  
Abbas MOHAMMADI

2016 ◽  
Vol 10 (1) ◽  
pp. 10-14
Author(s):  
Arvind K. Keshari ◽  
Ranjana Gupta

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


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