scholarly journals Systematic Investigation of Plant-Parasitic Nematodes Associated with Main Subtropical Crops in Guangxi Province, China

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1177
Author(s):  
Yi-Xue Mo ◽  
Ai-Su Mo ◽  
Zhuo-Qiu Qiu ◽  
Bing-Xue Li ◽  
Hai-Yan Wu
Keyword(s):  
High Frequency ◽  
Host Plants ◽  
Yield Loss ◽  
Systematic Investigation ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Guangxi Province ◽  
Large Area ◽  
Main Crop ◽  
Plant Parasitic

Plant parasitic nematodes (PPNs) are a pathogenic group that causes momentous crop yield loss by retarding plant growth and development through plant parasitization. In this study, the distribution of PPNs based on the main crops in Guangxi Province of China was investigated. A total of 425 samples of soil or roots from sugarcane, rice, maize, and soybean were collected in 68 counties, and a total of 48 order/family/genera of PPNs were identified, of which some genera were found in more than one crop. A total of 31 order/family/genera of PPNs were found in rice, among which Hirschmanniella was the most abundant, accounting for 79.23%, followed by Tylenchorhynchus (34.43%). Forty order/family/genera were observed in maize, of which the dominant genera were Pratylenchus and Tylenchorhynchus at 45.14% and 32.64%, respectively. In addition, 30 order/family/genera of PPNs were detected from sugarcane, and the percentages of Tylenchorhynchus and Helicotylenchus were 70.42% and 39.44%, respectively. The main crop of Eastern ecological regions was rice, with a high frequency of Hirschmanniella. The greatest frequency of Pratylenchus was found in the Western eco-region, which had a large area of maize. In the Northern eco-region, rice and maize were popular, with abundant Hirschmanniella and Helicotylenchus. In the Central eco-region, Pratylenchus was detected on the main crop of sugarcane. Hirschmanniella (72.94%) was dominant in clay, and Tylenchorhynchus (54.17%) showed the highest frequency in loam. The distribution of PPNs varied with different altitudes. The diversity of this phenomenon was closely related to host plants. These results could improve understanding of the distribution of PPNs and provide important information for controlling PPNs.

Occurrence and importance of plant-parasitic nematodes in organic farming in Germany

Nematology ◽  
2007 ◽  
Vol 9 (6) ◽  
pp. 869-879 ◽  
Author(s):  
Andrea Frankenberg ◽  
Andreas Paffrath ◽  
Johannes Hallmann ◽  
Harald Schmidt
Keyword(s):  
Organic Farming ◽  
High Frequency ◽  
Production Systems ◽  
Parasitic Nematodes ◽  
Yield Losses ◽  
Plant Parasitic Nematodes ◽  
Severe Damage ◽  
Production Factors ◽  
Main Emphasis ◽  
Plant Parasitic

AbstractIn an attempt to evaluate the occurrence and economic importance of plant-parasitic nematodes in organic farming in Germany, a survey was conducted with the main emphasis on vegetable and cereal production systems. For vegetables, the survey included quantification and identification of plant-parasitic nematodes in soil samples and a questionnaire for growers querying production factors and damage levels. For cereals, the survey focused on quantification and identification of plant-parasitic nematodes in soil and plant samples. Overall, Pratylenchus and Tylenchorhynchus were the most prominent nematode genera under both production systems with an incidence of over 90% of the samples. Meloidogyne was detected in 51% of the samples in both systems. Other nematode genera showed differences between the two production systems. In production systems with a high frequency of vegetables, Paratylenchus was detected in 56% of the samples and Heterodera in 15%, whereas in rotations with a high cropping frequency of cereals, incidences of plant-parasitic nematodes were 56% for Heterodera, 47% for Trichodorus and 45% for Paratylenchus. Yield losses could exceed 50% on carrots, onions and cereals and were most pronounced on sandy soils. In many cases, nematode problems started 5 to 10 years after conversion to organic farming. The survey indicated that plant-parasitic nematodes are widely spread in organic farming in Germany and can cause severe damage which may result in complete loss of the crop.

scholarly journals Survey of Plant-Parasitic Nematodes in Kansas and Eastern Colorado Wheat Fields

2014 ◽  
Vol 15 (3) ◽  
pp. 112-117 ◽  
Author(s):  
T. C. Todd ◽  
J. A. Appel ◽  
J. Vogel ◽  
N. A. Tisserat
Keyword(s):  
Great Plains ◽  
Yield Loss ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Economic Thresholds ◽  
Lesion Nematodes ◽  
Maximum Root ◽  
Root Lesion Nematodes ◽  
Plant Parasitic

Observations on the prevalence and abundance of plant-parasitic nematodes were made from soil and root samples collected from 2,640 wheat fields in Kansas and Colorado during 2007-2010. Stunt nematodes (predominately Merlinius brevidens and Quinisulcius acutus), root-lesion nematodes (predominately Pratylenchus neglectus), and pin nematodes (Paratylenchus projectus) were the most commonly encountered taxa. Maximum soil population densities of 6,520 and 1,880 nematodes/100 cm3 soil were observed for pin and stunt nematodes, respectively, while a maximum root population density of 90,309 nematodes/g dry root was observed for root-lesion nematodes. Lower nematode densities were associated with wheat following corn, grain sorghum, or soybean for pin and stunt nematodes, and with wheat following fallow for root-lesion nematodes. Based on the results of this survey, 6% and 8% of wheat acreage in the central Great Plains are estimated to be at risk for significant (>5%) yield loss due to stunt nematodes and root-lesion nematodes, respectively. The number of fields with high population densities of both stunt and root-lesion nematodes was negligible (1%); therefore, the total wheat acreage with nematode populations above provisional economic thresholds is estimated to be ∼13%. Damage relationships with greater accuracy, precision, and relevance are necessary to establish reliable yield loss estimates for this region. 3 June 2014. 11 August 2014.

scholarly journals Chemotaxis can take plant-parasitic nematodes to the source of a chemo-attractant via the shortest possible routes

2010 ◽  
Vol 8 (57) ◽  
pp. 568-577 ◽  
Author(s):  
Andy M. Reynolds ◽  
Tushar K. Dutta ◽  
Rosane H. C. Curtis ◽  
Stephen J. Powers ◽  
Hari S. Gaur ◽  
...  
Keyword(s):  
Host Plants ◽  
Experimental Studies ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Meloidogyne Graminicola ◽  
Chemical Gradients ◽  
Scant Attention ◽  
Primary Means ◽  
Preferred Hosts ◽  
Plant Parasitic

It has long been recognized that chemotaxis is the primary means by which nematodes locate host plants. Nonetheless, chemotaxis has received scant attention. We show that chemotaxis is predicted to take nematodes to a source of a chemo-attractant via the shortest possible routes through the labyrinth of air-filled or water-filled channels within a soil through which the attractant diffuses. There are just two provisos: (i) all of the channels through which the attractant diffuses are accessible to the nematodes and (ii) nematodes can resolve all chemical gradients no matter how small. Previously, this remarkable consequence of chemotaxis had gone unnoticed. The predictions are supported by experimental studies of the movement patterns of the root-knot nematodes Meloidogyne incognita and Meloidogyne graminicola in modified Y-chamber olfactometers filled with Pluronic gel. By providing two routes to a source of the attractant, one long and one short, our experiments, the first to demonstrate the routes taken by nematodes to plant roots, serve to test our predictions. Our data show that nematodes take the most direct route to their preferred hosts (as predicted) but often take the longest route towards poor hosts. We hypothesize that a complex of repellent and attractant chemicals influences the interaction between nematodes and their hosts.

scholarly journals An Approach to the Parasitism Genes of the Root Knot Nematode

2012 ◽  
Vol 1 (1) ◽  
pp. 81-87
Author(s):  
Ajit K. Ngangbam ◽  
Nongmaithem B. Devi
Keyword(s):  
Host Plants ◽  
Parasitic Nematodes ◽  
Secretory Proteins ◽  
Single Source ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Root Cells ◽  
Esophageal Gland ◽  
Parasitism Genes ◽  
Plant Parasitic

Plant parasitic nematodes which are highly successful parasites evolved a very specialized feeding relationship with the host plant to cause the destructive root-knot disease. They initiate their parasitic relationship with the host by releasing their secretions into root cells which in turn stimulate the root cells of the host to become specialized feeding cells which are considered as the single source of nutrients essential for the nematode's survival. The parasitism genes expressed in nematode's esophageal gland cells encode secretory proteins that are released through its stylet to direct the interactions of the nematode with its host plants.

scholarly journals The ACE Genes in Aphelenchoides Besseyi Isolates and Their Expression Correlation to the Fenamiphos Treatment

2021 ◽  
Author(s):  
Jung-Kai Hsu ◽  
Chia-Wei Weng ◽  
Jeremy J.W. Chen ◽  
Peichen J. Chen
Keyword(s):  
Yield Loss ◽  
Point Mutations ◽  
Acetylcholinesterase Inhibitors ◽  
Ache Inhibitor ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Invertebrate Species ◽  
Great Yield ◽  
Aphelenchoides Besseyi ◽  
Plant Parasitic

Abstract Aphelenchoides besseyi could cause great yield loss on rice and many economically important crops. Acetylcholinesterase inhibitors were commonly used to mitigate plant parasitic nematodes. However, increasing nematicide-resistance has been reported due to the extensive use of these chemicals. The correlation between the AChE-inhibitor (fenamiphos) sensitivities and acetylcholinesterase (ace) genes in two isolates of A. besseyi (designated Rl and HSF) was established. The LD50 of fenamiphos to Rl and HSF were 572.2 ppm and 129.4 ppm, respectively, indicating that two nematode isolates had different sensitivities to fenamiphos. Three ace genes were cloned and sequenced in A. besseyi, and their homology was supported by phylogenic analysis with AChEs protein sequences from various vertebrate and invertebrate species. Molecular docking showed that the affinities of each AChEs to fenamiphos were higher in HSF isolate, indicating that there should be point mutations in Rl isolate AChEs. Treating the two isolates with 100 ppm fenamiphos for 12 h, three ace genes of HSF isolate were down-regulated but were up-regulated in Rl isolate. The results suggest that fenamiphos can transcriptionally modulate the expression of ace genes, as well as the variants in AChEs and increased expression of ace genes might be associated with fenamiphos-insensitivity in Rl isolate.

scholarly journals DISTRIBUTION AND POPULATION DENSITIES OF PLANT-PARASITIC NEMATODES ASSOCIATED WITH GINGER (ZINGIBER OFFICINALE) IN KADUNA STATE, NIGERIA

2020 ◽  
Vol 4 (3) ◽  
pp. 496-504
Author(s):  
Julius Bulus ◽  
Peter Abraham ◽  
Mercy Joshua ◽  
Dauda Elisha Shamaki ◽  
Christopher Tobe Okolo ◽  
...  
Keyword(s):  
Yield Loss ◽  
Zingiber Officinale ◽  
Economic Importance ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Population Average ◽  
Percentage Similarity ◽  
Important Cash Crop ◽  
Plant Parasitic

Ginger (Zingiber officinale) is an important cash crop in Nigeria. In spite of the economic importance of plant-parasitic nematodes reported on ginger, little or no information is available as regards plant-parasitic nematodes diversity and abundance on ginger in Nigeria. This work was conducted in 2018 to identify plant-parasitic nematodes associated with ginger in Kaduna state and to determine their population densities. Three Local Government Areas (LGA) were visited and between 12 to 16 ginger farms were sampled per LGA. A total of 42 soil samples was collected at a depth of 0 - 30 cm of the plant rhizosphere. Plant-parasitic nematodes were extracted from the soil using modified sieving and decanting method. Identification to genera level was done using identification keys viewing with dissecting microscope at X40 magnification. Nineteen (19) genera of plant-parasitic nematodes were identified, with 12 genera occurring in all LGA(s). Scutellonema (113.33), Meloidogyne (110), and Pratylenchus (93.33) were the most abundant per 100 ml of soil when locations are combined. Plant-parasitic nematodes population average was 870-950 per 100 ml of soil. All locations showed a high percentage similarity of plant-parasitic nematodes diversity and were statistically similar. This high diversity and population abundance can be among the reasons for the low productivity of ginger in Nigeria. It is therefore important to educate farmers on the economic importance of plant-parasitic nematodes on ginger and its management. Further research using the most occurring genera to establish the threshold population densities capable of causing economic yield loss needs to be conducted

scholarly journals Nematode Management in Cole Crops

EDIS ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 13
Author(s):  
Z. J. Grabau ◽  
J. W. Noling
Keyword(s):  
Yield Loss ◽  
Cultural Practices ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Fact Sheet ◽  
Nematode Management ◽  
Cole Crops ◽  
Plant Parasitic ◽  
Agricultural Professionals

Many different plant-parasitic nematodes cause yield loss in cabbage, broccoli, collards, and other valuable Florida cole crops. This 13-page fact sheet written by Z. J. Grabau and J. W. Noling and published by the UF/IFAS Entomology and Nematology Department lists common symptoms, explains how to submit samples to a nematology lab such as the UF/IFAS Nematode Assay Lab for diagnosis, and describes key cultural practices to help agricultural professionals spot and manage nematode problems in cole crops.

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