scholarly journals Prevalence and Molecular Diversity of Plant-Parasitic Nematodes of Yam (Dioscorea spp.) in China, with Focus on Merlinius spp.

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1299
Author(s):  
Sulaiman Abdulsalam ◽  
Huan Peng ◽  
Yingjuan Yao ◽  
Linjuan Fan ◽  
Ru Jiang ◽  
...  

There is little information about nematode pests associated with yam in China. Between 2020 and 2021, surveys of yam fields were conducted to investigate the abundance and prevalence of plant-parasitic nematodes in major yam growing areas. A total of 110 bulk soil samples from the yam rhizosphere and 48 yam tubers were collected from seven counties in Jiangxi and Shandong provinces. Standard protocols were used to extract nematodes from soil and tubers and identified at the genus level. In this study, 16 species and 13 nematode genera were recorded. The five most prominent species on the yam rhizosphere according to mean population densities were Pratylenchus coffeae (291/individuals), Meloidogyne (262/individuals), Rotylenchulus reniformis (225/individuals), Merlinius (224/individuals), and Helicotylenchus dihystera (171/individuals). In the tubers, the three most prominent species were Pratylenchus coffeae (415/individuals), Meloidogyne (331/individuals), and Rotylenchulus reniformis (115/individuals). These species were verified with appropriate molecular analysis. The high prevalence of the ectoparasite (Merlinius spp.) on the rhizosphere of yam also revealed that Merlinius spp. May be more important to yam than previously thought. Morphological and molecular analyses further confirmed the identity of the species as Merlinius brevidens and were characterized for the first time on yam in China. Minor morphometrical differences (slightly longer body and stylet) were observed in Chinese populations of M. brevidens compared to the original description. Additionally, this study reveals that M. brevidens isolated from China showed a higher nucleotide sequence in the ITS region compared to M. brevidens populations from India. This finding provides baseline information on the nematode pest occurrence on yam in China and calls for effective management.

1969 ◽  
Vol 66 (1) ◽  
pp. 52-59
Author(s):  
D. Oramas ◽  
J. Román

A survey was conducted through the five argricultural regions of Puerto Rico to determine distribution and population density of the nematode species associated with plantain. Fourteen genera, represented by 19 species of phytoparasitic nematodes were found in association with the crop: Ditylenchus, Helicotylenchus, Hoplolaimus, longidorus, Meloidogyne, Paratylenchus, Pratylenchus, Pseudhalenchus, Quinisulcius, Radopholus, Rotylenchulus, Tylenchorhynchus, Tylenchus, and Xiphinema. Meloidogyne incognita, Helicotylenchus spp., Radopholus similis, and Rotylenchulus reniformis were the most widely distributed nematode species throughout the Island. On the other hand, M. incognita, P. coffeae, R. similis, Helicotylenchus spp. , and R. reniformis had higher population densities.


2018 ◽  
Vol 13 (2) ◽  
pp. 178 ◽  
Author(s):  
Willian César Terra ◽  
Júlio Carlos Pereira da Silva ◽  
Vicente Paulo Campos ◽  
Sônia Maria De Lima Salgado

<p>Understanding the mechanisms of plant-parasitic nematodes (PPN) dispersion is vital to improve control strategies aiming to restrict dissemination of these plant parasites. In the present work, we evaluated the presence of PPN in Arabic coffee (<em>Coffea arabica</em>) seedlings produced in commercial nurseries in Minas Gerais, state, Brazil. A total of 2830 samples obtained from 318 coffee nurseries, in 84 counties within the South and Zona da Mata regions in Minas Gerais, Brazil and representing more than 62 million coffee seedlings, were analyzed. <em>Meloidogyne</em> spp. was identified in 11 samples from four counties. <em>Pratylenchus spp</em>. and <em>Rotylenchulus reniformis</em> were detected in 281 and 47 samples, respectively. According to the Regulatory Instruction N° 35 from the Ministry of Agriculture, Livestock and Food Supply (MAPA), in Brazil, coffee seedlings infected by <em>Meloidogyne</em> spp. are prohibited for commercialization and/or planting. However, such restrictions do not apply to other PPN. Therefore, seedlings sold in Minas Gerais may constitute sources of dissemination for root-lesion nematodes (<em>Pratylenchus</em> spp.) and the reniform nematode (<em>R. reniformis</em>).</p>


HortScience ◽  
2019 ◽  
Vol 54 (1) ◽  
pp. 125-128
Author(s):  
Cody L. Smith ◽  
Joshua H. Freeman ◽  
Nancy Kokalis-Burelle ◽  
William P. Wechter

Fusarium wilt [caused by the fungus Fusarium oxysporum f. sp. niveum (FON)] has been a consistent problem in watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] production worldwide. One method for combatting this pathogen in the field is to graft a susceptible, high-yielding scion on to a fusarium wilt-resistant rootstock. A concerning issue with rootstocks resistant to fusarium wilt is that they have not been tested for their susceptibility to plant pathogenic nematodes—specifically, root-knot nematodes (RKNs; Meloidogyne spp.) and the reniform nematode (Rotylenchulus reniformis). Preliminary findings have demonstrated that many of these Fusarium-resistant rootstocks are highly susceptible to RKNs. Research was conducted during the Spring and Fall 2015 and 2016 to evaluate the resistance to RKN and reniform nematode in rootstocks with known resistance to fusarium wilt. Six rootstocks were evaluated over the course of four experiments. A nematode-susceptible interspecific hybrid [Cucurbita maxima (Duchesne) × C. moschata (Duchesne)] rootstock ‘Carnivor’ was included as a susceptible control in both years. Results demonstrated that several Citrullus lanatus var. citroides (L.H. Bailey) rootstocks (‘Carolina Strongback’, USVL246-FR2, USVL252-FR2, and USVL-360) and ‘SP-6’ (a commercially available pollinizer cultivar) exhibited resistance to plant parasitic nematodes when compared with the susceptible control. Partial resistance was observed in USVL-482351. When compared with the control, these rootstocks also had fewer Meloidogyne spp. and R. reniformis in root tissue. These findings indicate that rootstocks may be available to manage both fusarium wilt and RKN in grafted cucurbit production system.


2021 ◽  
Vol 10 (9) ◽  
Author(s):  
Sergey V. Tarlachkov ◽  
Irina P. Starodumova ◽  
Lubov V. Dorofeeva ◽  
Natalia V. Prisyazhnaya ◽  
Tatiana V. Roubtsova ◽  
...  

ABSTRACT Draft genome sequences of 28 strains of Microbacteriaceae from plants infested by plant-parasitic nematodes were obtained using Illumina technology. The sequence data will provide useful baseline information for the development of comparative genomics and systematics of Microbacteriaceae and facilitate understanding of molecular mechanisms involved in interactions between plants and nematode-associated bacterial complexes.


2020 ◽  
Vol 7 (1) ◽  
pp. 044-048
Author(s):  
Vinod Kumar ◽  
◽  
Prakash Banakar ◽  
Anil Kumar ◽  
Priyanka Duggal ◽  
...  

An extensive survey was conducted to assess the frequency and abundance of plant-parasitic nematodes associated with cotton (Gossypium hirsutum L.) in Haryana (Nuh and Palwal districts) during 2018-20. Based on incidence, population density and associated damage on affected crops, root-knot nematode (Meloidogyne incognita) was considered to be the most important parasite of the crops under local condition. During 2018-19, a total of 11 soil and root samples of cotton were collected from Nuh and Palwal districts. Out of these, eight were found infected with M. incognita with 72.0% frequency of occurrence. The results revealed that out of 7 samples (Nuh), five were found infested with M. incognita with 71.4% frequency of occurrence. In Palwal district, this nematode had 75.0% frequency of occurrence with density range of 60-300 j2 200-1 cc soil. During 2019-20, a total of 27 soil and root samples of cotton were collected from Nuh and Palwal districts. Out of these, 14 were found infected with M. incognita with 51.8% frequency of occurrence. The results revealed that out of 21 samples (Nuh), 12 were found infested with M. incognita with 57.1% frequency of occurrence and density range of 95-690 j2 200-1 cc soil. In Palwal district, this nematode had 33.3% frequency of occurrence (2 out of 6 samples) with density range of 135-435 j2 200-1 cc soil. Other plant parasitic nematodes which were found associated with the cotton belonged to Rotylenchulus reniformis, Hoplolaimus sp., Helicotylenchus sp. and Tylenchorhynchus sp.


Nematology ◽  
2012 ◽  
Vol 14 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Prasanna Holajjer ◽  
Anju Kamra ◽  
Hari S. Gaur ◽  
Dolly Wattal Dhar

The nematicidal activity of a terrestrial cyanobacterium, Synechococcus nidulans, was investigated. Extracts of S. nidulans cultures collected at weekly intervals for 5 weeks were sonicated and tested against second-stage juveniles (J2) of Meloidogyne incognita. Extracts of 2-week-old cultures caused the maximum immobility (94.2%) and mortality (29.3%) of J2, compared with controls (medium and water). This extract was tested in vitro against infective stages and hatch of M. graminicola, Heterodera cajani, H. avenae and Rotylenchulus reniformis. Extracts of sonicated S. nidulans caused a mean immobility in the range of 91.3-98.4% in infective stages of the nematodes, with no significant difference with an increase in exposure time from 24 to 72 h. The greatest mean percentage mortality was observed in M. graminicola (31.5%) followed by M. incognita (29.3%), H. avenae (20.9%), and R. reniformis and H. cajani (both 17.4%) with a significant increase with the period of exposure from 24 to 72 h. No significant differences in mortality were observed between M. graminicola and M. incognita and between H. avenae and H. cajani. The percentage hatch inhibition over control (water) was greatest in M. incognita (94.2%), followed by H. avenae (91.6%), H. cajani (72.3%) and M. graminicola (70.6%), and least in R. reniformis (58.6%).


Nematology ◽  
2002 ◽  
Vol 4 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Patrick Quénéhervé ◽  
Ronan Le Saux

AbstractThe orientation of juveniles of Meloidogyne incognita and Rotylenchulus reniformis was studied in salt gradients created in a linear agarose gel. Twelve combinations of calcium, potassium, sodium or ammonium cations and chloride, nitrate or sulphate anions were tested. The orientation of juveniles of M. incognita was induced by the constitutive cation of the salt, e.g., calcium salts had no effect while the other salts and especially ammonium salts and ammonium nitrate were strongly repellent. In contrast, the orientation of juveniles of R. reniformis was induced by the constitutive anion of the salt, e.g., chloride salts were found to be repellent while sulphate and nitrate salts were attractive. These results are discussed as possible novel control strategies for economically important plant parasitic nematodes. In other respects, these differences in chemical preferences may partly explain the observed geographical distribution of these nematode species according to the ionic content of the soils.


2020 ◽  
Vol 21 (supplement 1) ◽  
Author(s):  
Shimpy Sarkar ◽  
Kusal Roy ◽  
Arshdeep Singh

In a survey of four major groundnut growing blocks of the Hooghly district of West Bengal forty-three samples of soil were sampled for the purpose of studying the occurrence and distribution of rhizospheric nematodes population. Community study revealed presence of six nematode genera viz., Criconemoides, Rotylenchulus, Tylenchorhynchus, Meloidogyne, Hirschmanniella, and Pratylenchus in the rhizosphere of groundnut crop. Most predominant phytonematode in groundnut has been identified as Criconemoides sp. which is followed by Rotylenchulus and Tylenchorhynchus. The species of nematodes such as Meloidogyne incognita and Meloidogyne javanica were identified. Criconemoides sp. and Tylenchorhynchus mashhoodi were recorded highest from Chiladangi area of Pursurah block of Hooghly district. Meloidogyne incognita was recorded maximum from Haripal block. Rotylenchulus reniformis was also recorded in huge number from Samanta Road areas of Pursurah block. Apart from these plant parasitic nematodes, mononchids (especially Mylonchulus sp.) the predatory nematodes and saprophytic nematodes have also shown their presence in the population of the wide ranged nematodes associated with groundnut crop.


Author(s):  
D. J. Hunt

Abstract In this Appendix section, all genera and species of plant parasitic nematodes cited in the book are listed alphabetically. The genera and species are followed by their 'authorities', i.e. the name(s) of the author(s) of the original description, in some cases followed by the name(s) of the author(s) who have published the more recent valid taxonomic name, that is, by placing the species in another genus. In such cases, the original authorities are placed in parentheses. Both authorities are followed by their respective year of publication. The most common synonyms are also listed alphabetically as 'cf.'. For each genus, the group to which it is currently assigned is indicated in square brackets as follows: Tyl., Tylenchina (Tylenchomorpha); A., Aphelenchoididae (Tylenchomorpha); L., Longidoridae (Dorylaimina); P., Panagrolaimidae (Rhabditida); T., Tylencholaimidae (Dorylaimina); Tri., Trichodoridae (Diphtherophorina).


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