scholarly journals Phytonematodes Associating Wheat in North Eastern Egypt and Pathogenicity of Heterodera avenae on Certain Cereal Cultivars

2020 ◽  
Vol 9 (3) ◽  
pp. 165-172
Author(s):  
Sahar H. Abdel-Baset ◽  
Ahmed A. M. Dawabah
Keyword(s):  
Growth Parameters ◽  
Heterodera Avenae ◽  
Parasitic Nematodes ◽  
Initial Population ◽  
Wheat Roots ◽  
Nematode Reproduction ◽  
Growing Seasons ◽  
North Eastern ◽  
Moderately Resistant ◽  
Cereal Cultivars

A survey of plant-parasitic nematodes (PPNs) associating wheat in Ismailia governorate, northeastern Egypt was carried-out during 2016/2017 and 2017/2018 growing seasons. Results showed that seven PPNs genera and/or species were found associating wheat roots. These genera and/or species, in descending order of frequency, were: Tylenchorhynchus spp. (14%), Helicotylenchus spp. (10%), Heterodera avenae (8%), Ditylenchus spp. (5%), Meloidogyne javanica (4%), Pratylenchus spp. and Xiphinema spp. (3%, each). Two screening pot experiments, in two consecutive growing seasons (2017/17 and 2017/18) were carried out to determine the host suitability of 15 Egyptian cereal cultivars including bread wheat (Triticum aestivum), barley (Hordeum vulgare) and oat (Avena sativa) to the cereal cyst nematode, Heterodera avenae, under greenhouse conditions. Results of both experiments were very similar and showed that oat cv. Baladi and wheat cv. Giza 171 were highly susceptible, while wheat cvs. Masr 1, Masr 2, Masr 3, Sakha 95, Seds 1, Seds 12, and Shandawel 1 were susceptible. However, barley cvs. Giza 135, Giza 123, Giza 124, and Giza 125 were found to be moderately resistant to the tested nematode. H. avenae suppressed (P ≤ 0.05) the dry weights of roots, shoots and spikes of the inoculated plants, compared to the non-inoculated checks. Another greenhouse pot experiment was carried out during the wheat-growing season 2018/2019 to determine the effect of different initial population densities (Pi) of H. avenae on the growth parameters of wheat cv. Giza 171 and on nematode reproduction. Results showed that as the nematode Pi increased, both the wheat growth parameters and the nematode reproduction factor (Rf) were decreased (P ≤ 0.05).

Damage potential and reproduction of Heterodera avenae on wheat and barley under Saudi field conditions

Nematology ◽  
1999 ◽  
Vol 1 (6) ◽  
pp. 625-630 ◽  
Author(s):  
Ahmed Ibrahim ◽  
Ahmad Al-Hazmi ◽  
Fahad Al-Yahya ◽  
Ali Alderfasi
Keyword(s):  
Grain Yield ◽  
Barley Grain ◽  
Field Conditions ◽  
Barley Straw ◽  
Heterodera Avenae ◽  
Initial Population ◽  
Damage Potential ◽  
Nematode Reproduction ◽  
Growing Seasons ◽  
Linear Regressions

Abstract This study was conducted to determine the effect of H. avenae initial population densities (Pi) on the yield of wheat (two growing seasons) and barley (one season) and on nematode reproduction, under Saudi field conditions. At increasing Pi, H. avenae suppressed (P lessequal 0.05) the number of spikes, weight of spikes, weight of 1000 kernels, grain yield and straw yield of wheat and barley. Grain yields were reduced by 40 to 92% for wheat (during the two seasons) and 17 to 77% for barley. Straw yields were also reduced, by 50 to 85 for wheat and 30 to 77% for barley. As Pi increased, final populations of H. avenae increased (P lessequal 0.05) on both hosts, but the nematode reproduction factor (Rf) decreased. Significant negative linear regressions were obtained between H. avenae Pi and grain yield of wheat and barley. Final populations (Pf) were positively correlated with Pi on wheat and on barley. Rf was negatively correlated with Pi on wheat and barley. Schadigungspotential und Vermehrung von Heterodera avenae an Weizen und Gerste unter Freilandbedingungen in Saudiarabien - Die vorliegende Untersuchung wurde durchgefuhrt, um die Wirkung unterschiedlicher Ausgangspopulationen (Pi) von Heterodera avenae auf den Ertrag von Weizen (zwei Vegetationsperioden) und Gerste (eine Vegetationsperiode) sowie auf die Vermehrung der Nematoden unter saudiarabishen Freilandbedingungen zu ermitteln. Bei steigender Pi verminderte (P lessequal 0.05) H. avenae die Anzahl der Ahren, das Ahrengewicht, das Tausendkorngewicht, den Korn- und den Strohertrag von Weizen und Gerste. Die Kornertrage wurden bei Weizen (zwei Vegetationsperioden) um 40-92% vermindert, bei Gerste um 17-77%. Auch die Strohertrage gingen zuruck, bei Weizen um 50-85% und bei Gerste um 30-77%. Mit zunehmender Pi stiegen die Endpopulationsdichten von H. avenae bei beiden Wirtspflanzen an (P lessequal 0.05), doch nahm der Vermehrungsfaktor (Rf) der Nematoden ab. Zwischen Pi von H. avenae und dem Kornertrag von Weizen und Gerste wurden signifikante negative Regressionen erhalten. Die Endpopulationen (Pf) waren an Weizen und Gerste positiv korreliert mit Pi. Rf war an Weizen und Gerste negativ korreliert mit Pi.

Organic amendments with and without a synthetic nematicide for the management of Heterodera avenae in wheat

Nematology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Saroj Yadav ◽  
Rambir S. Kanwar ◽  
Jaydeep A. Patil
Keyword(s):  
Growth Parameters ◽  
Farmyard Manure ◽  
Winter Season ◽  
Organic Amendments ◽  
Heterodera Avenae ◽  
Nematode Reproduction ◽  
Neem Cake ◽  
Castor Cake ◽  
Higher Doses ◽  
Better Than

Summary This experiment was conducted in the screenhouse of the Department of Nematology, CCS Haryana Agricultural University, Hisar, India, in 2015-2016 and 2016-2017 during the Rabi (winter) season to evaluated organic amendments with and without nematicide for the management of the cereal cyst nematode, Heterodera avenae, in wheat. Organic amendments – castor cake, neem cake, vermi compost and farmyard manure (FYM), individually or with Carbofuran 3G (25 mg pot−1) – were applied in pots 10 days before sowing. All organic amendments significantly reduced the nematode population compared to the inoculated control in both years. The higher doses of the amendments were better at controlling H. avenae than the lower dose. Among the organic amendments, neem cake significantly reduced nematode reproduction compared to other amendments. Significantly fewer cysts, 75 (kg soil)−1, were found in treatment with neem cake at 20 g (kg soil)−1 combined with nematicide. The greatest plant growth parameters were observed under castor cake at 20 g (kg soil)−1 in combination with nematicide. Combined applications of organic amendments with the synthetic nematicide were better than without nematicide.

scholarly journals Resistance screening of lentil cultivars against the root-knot nematode Meloidogyne incognita

2018 ◽  
Vol 11 (1) ◽  
pp. 9-18 ◽  
Author(s):  
T. Ansari ◽  
M. Asif ◽  
M.A. Siddiqui
Keyword(s):  
Plant Growth ◽  
Meloidogyne Incognita ◽  
Growth Parameters ◽  
Dry Weight ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Nematode Reproduction ◽  
Egg Masses ◽  
Moderately Resistant ◽  
Reduction Percentage

SummaryThe root-knot nematodeMeloidogyne incognitais a major soil parasite of lentil crops. Increasing restrictions of chemical nematicides have triggered a growing attention and interest in alternate root-knot nematode management. The present study was conducted to examine the level of resistance and/or susceptibility of five lentil cultivars (PL-456, KLS-218, Desi, DPL-62, Malika), grown in pots, against the root-knot nematodeM. incognita. Root-knot nematode reproduction and host damage were assessed by recording the nematode infestation levels and reduction percentage of plant growth parameters. Nematode response and plant growth differentiated amongst the lentil cultivars. None of the cultivars was found immune or highly resistant. The cultivar Malika was found moderately resistant as it showed the lowest number of galls and egg masses/root as well as the lowest reduction of plant fresh weight (10.4%) and dry weight (6.9%). On the other hand, the cultivar Desi manifested the highest susceptibility exhibiting the highest number of galls and egg masses. There was a significantly negative correlation between the number of galls and plant growth parameters (plant fresh and dry weight and plant height).

scholarly journals Fungicide strategies and resistance of Ramularia collo-cygni to demethylation and succinate dehydrogenase inhibitors in Austrian winter barley (Hordeum vulgare)

2021 ◽  
Author(s):  
Thomas Assinger ◽  
Stefano F. F. Torriani ◽  
Salvatore Accardo ◽  
James Fountaine ◽  
Siegrid Steinkellner
Keyword(s):  
Succinate Dehydrogenase ◽  
Fungicide Resistance ◽  
Growth Parameters ◽  
Field Trials ◽  
Low Frequencies ◽  
Resistance Strategies ◽  
Growing Seasons ◽  
Ramularia Leaf Spot ◽  
Application Frequency ◽  
Succinate Dehydrogenase Inhibitors

AbstractRamularia collo-cygni B. Sutton and J.M. Waller is a major disease in Austrian barley-growing regions. To date, fungicide application is the most effective method to manage the disease; however, fungicide resistance to demethylation and succinate dehydrogenase inhibitors has developed over the last few years. In the growing seasons 2016/2017 and 2017/2018, field trials were carried out to analyze the efficiency of fungicide strategies based on different fungicide classes. Disease development, growth parameters and monitoring of CYP51 and sdh mutations were determined. Fungicide treatments resulted in higher disease control, green leaf area and grain yield. In Austrian R. collo-cygni field populations, the frequency of the mutations CYP51-I325T and CYP51-I328L was low to moderate. Frequency of mutations sdhC-H146R and sdhC-H153R was low. Frequencies of CYP51-I325T and -I328L were similar and increased following DMI application. Frequency of sdhC-H146R was higher compared to sdhC-H153R. The SDHI benzovindiflupyr showed a higher selection rate for sdh mutations compared to bixafen. These sdh mutations were not selected if chlorothalonil was used as mixing partner, leading to a stable composition of sdh resistance alleles over the last two years. Chlorothalonil was proven to be an effective tool for anti-resistance strategies. Currently, SDHIs and DMIs are the backbone of Ramularia leaf spot control in Austria; however, the level of resistance is likely to increase in absence of suitable anti-resistance strategies and following the ban of chlorothalonil.

scholarly journals Effect of coffee silver skin and brewers’ spent grain in the control of root-knot nematodes

2019 ◽  
Vol 56 (1) ◽  
pp. 30-41 ◽  
Author(s):  
N. Thligene ◽  
G. N. Mezzapesa ◽  
D. Mondelli ◽  
A. Trani ◽  
P. Veronico ◽  
...  
Keyword(s):  
Control Strategies ◽  
Nematode Population ◽  
Parasitic Nematodes ◽  
Initial Population ◽  
Infested Soil ◽  
Soil Nematode ◽  
Root Knot Nematode ◽  
Tomato Plants ◽  
Industry Waste ◽  
Spent Grain

SummaryPlant parasitic nematodes (PPN) are important pests of numerous agricultural crops especially vegetables, able to cause remarkable yield losses correlated to soil nematode population densities at sowing or transplant. The concern on environmental risks, stemming from the use of chemical pesticides acting as nematicides, compels to their replacement with more sustainable pest control strategies. To verify the effect of aqueous extracts of the agro-industry waste coffee silverskin (CS) and brewers’ spent grain (BSG) on the widespread root-knot nematode Meloidogyne incognita, and on the physiology of tomato plants, a pot experiment was carried out in a glasshouse at 25 ± 2 °C. The possible phytotoxicity of CS and BSG extracts was assessed on garden cress seeds. Tomato plants (landrace of Apulia Region) were transplanted in an artificial nematode infested soil with an initial population density of 3.17 eggs and juveniles/mL soil. CS and BSG were applied at rates of 50 and 100 % (1L/pot). Untreated and Fenamiphos EC 240 (nematicide) (0.01 μL a.i./mL soil) treated plants were used as controls. Reactive oxygen species (ROS) and chlorophyll content of tomato plants were estimated during the experiment. CS extract, at both doses, significantly reduced nematode population in comparison to the untreated control, although it was less effective than Fenamiphos. BSG extract did not reduce final nematode population compared to the control. Ten days after the first treatment, CS 100 %, BSG 50 % and BSG 100% elicited the highest ROS values, which considerably affected the growth of tomato plants in comparison to the untreated plants. The control of these pests is meeting with difficulties because of the current national and international regulations in force, which are limiting the use of synthetic nematicides. Therefore, CS extracts could assume economic relevance, as alternative products to be used in sustainable strategies for nematode management.

scholarly journals First Report of the Spiral Nematode Scutellonema brachyurum on Lilyturf in the United States

Plant Disease ◽  
2011 ◽  
Vol 95 (1) ◽  
pp. 74-74 ◽  
Author(s):  
P. Agudelo ◽  
D. Harshman
Keyword(s):  
United States ◽  
Population Density ◽  
The United States ◽  
Parasitic Nematodes ◽  
Initial Population ◽  
Herbaceous Plant ◽  
Plant Parasitic Nematodes ◽  
Essential Information ◽  
First Report ◽  
Plant Parasitic

Lilyturf (Liriope muscari (Decne.) L.H. Bailey), an herbaceous plant, is commonly used in landscaping including borders (along sidewalks, driveways, and trees) and mass plantings as groundcover in the southeastern United States. In December of 2009, a soil sample was submitted to our lab for diagnosis of plant-parasitic nematodes from an area planted with lilyturf located on the Clemson University main campus. A high population density (1,220 individuals/100 cm3 of soil) of spiral nematodes (Scutellonema brachyurum (Steiner, 1938) Andrássy, 1958) was found by routine extraction by sugar centrifugal flotation (3). Other plant-parasitic nematodes, mainly ring nematodes (10 individuals/100 cm3) and stubby root nematodes (10 individuals/100 cm3), were present. To verify if high numbers of spiral nematodes were consistently associated with lilyturf, 20 additional soil and root samples were collected from different places on the campus. In all cases, S. brachyurum was found in densities ranging from 680 to 1,600 individuals/100 cm3 of soil (average of 1,210 individuals/100 cm3). The species was identified by morphological characters of females, including well developed stylet (26 to 30 μm long), no spermatheca, no sperm in uterus, tail broadly rounded with 8 to 12 annules between anus and tail, and scutella at anus level. As is commonly the case for this species, no males were found in any of the samples collected. Examination of the roots revealed numerous, small, reddish brown, necrotic lesions, apparently caused by the feeding and penetration of S. brachyurum. Host plant suitability and pathogenicity of the nematode were tested in the greenhouse. Ten nematode-free lilyturf plants grown individually in 15-cm-diameter plastic pots with pasteurized soil were inoculated with 1,000 spiral nematodes each. Ten uninoculated plants were kept under identical conditions as controls. Three months after inoculation, soil population densities were measured and reproduction factors were calculated to be between 2.8 and 5.4 (final population density divided by initial population density) for the 10 plants. Characteristic lesions previously described were observed in the roots of all inoculated plants, along with slight chlorosis of foliage. These symptoms were not observed on control plants. Spiral nematodes may attack the roots and stolons of lilyturf as ectoparasites or they may enter them and feed in the cortex as endoparasites. Although root lesions were common on affected plants, root injury in general was not severe and generalized root decay was not observed on either the collected plants or those from the greenhouse study. Reports on the pathogenicity of S. brachyurum are variable. Moderate damage was recorded on amaryllis and other ornamentals (4), while measurable damage was observed on tobacco (2), with approximately 100 individuals/100 cm3 of soil, and severe damage on Aloe vera ((L.) Burm. f.), with approximately 500 individuals/100 cm3 (1). To our knowledge, this is the first report of S. brachyurum causing visible symptoms on lilyturf. As the interstate and international movement of perennial plants continues to grow, awareness of the host status of potentially harmful nematodes becomes essential information. References: (1) R. P. Esser et al. Nematropica 16:65, 1986. (2) T. W. Graham. Phytopathology (Abstr.) 45:347, 1955. (3) W. R. Jenkins. Plant Dis. Rep. 48:692, 1964. (4) L. Nong and G. F. Weber. (Abstr.) Phytopathology 54:902, 1964.

Identification of a putative expansin gene expressed in the subventral glands of the cereal cyst nematode Heterodera avenae

Nematology ◽  
2012 ◽  
Vol 14 (5) ◽  
pp. 571-577 ◽  
Author(s):  
Haibo Long ◽  
Deliang Peng ◽  
Wenkun Huang ◽  
Yanke Liu ◽  
Huan Peng
Keyword(s):  
Cyst Nematode ◽  
Developmental Expression ◽  
Heterodera Avenae ◽  
Parasitic Nematodes ◽  
Secretory Proteins ◽  
Expansin Gene ◽  
Genes Encoding ◽  
Juvenile Stages ◽  
Stage Process ◽  
Parasitism Genes

Parasitism genes encoding secretory proteins expressed in the pharyngeal glands of plant-parasitic nematodes play important roles in the parasitic process. A new expansin gene (Ha-expb1) expressed in the subventral glands of the sedentary cyst nematode, Heterodera avenae, was cloned. Southern blot analysis suggested that Ha-expb1 is a member of a multigene family. The deduced protein Ha-EXPB1 consists of a signal peptide, a CBM II and an expansin domain, and was significantly similar to expansins and expansin-like proteins from the potato cyst nematode, Globodera rostochiensis, and the pine wood nematodes, Bursaphelenchus spp. In situ hybridisation showed that Ha-expb1 transcript specifically accumulated in the two subventral gland cells of the second-stage juveniles. Developmental expression confirmed that its transcript abundances were high in the motile juvenile stages and low in the sedentary stage of the nematode, implying a role in the early parasitic-stage process, most likely in aiding migration within the plant.

scholarly journals Grapevine Resistance to the Nematode Xiphinema index Is Durable in Muscadine-Derived Plants Obtained from Hardwood Cuttings but Not from In Vitro

2020 ◽  
Vol 110 (9) ◽  
pp. 1565-1571
Author(s):  
Van Chung Nguyen ◽  
Jean-Pascal Tandonnet ◽  
Samira Khallouk ◽  
Cyril Van Ghelder ◽  
Ulysse Portier ◽  
...  
Keyword(s):  
Natural Resistance ◽  
Parasitic Nematodes ◽  
Promising Alternative ◽  
Nematode Reproduction ◽  
Xiphinema Index ◽  
Plant Nematode ◽  
Hardwood Cutting ◽  
Muscadinia Rotundifolia ◽  
Reproduction Factor

Breeding for varieties carrying natural resistance (R) against plant-parasitic nematodes is a promising alternative to nematicide ban. In perennial crops, the long plant−nematode interaction increases the risk for R breaking and R durability is a real challenge. In grapevine, the nematode Xiphinema index has a high economic impact by transmitting Grapevine fanleaf virus (GFLV) and, to delay GFLV transmission, rootstocks resistant to this vector are being selected, using Muscadinia rotundifolia in particular as an R source. To optimize in fine this strategy, the durability has been studied under controlled conditions in F1 and BC1 muscadine-derived resistant accessions previously obtained from either hardwood-cutting or in vitro propagation. After inoculation with a mix, in equal proportions, of four lines representative of the X. index diversity, multiplication on plants has been monitored 3 to 6 years. The nematode reproduction factor remained lower than 1 in resistant plants obtained from hardwood cuttings while it increased at values far beyond 1 in resistant plants of in vitro origin. Data for nematode numbers per gram of roots mostly paralleled those obtained for the reproduction factor. The effect of the propagation type on resistance over years was also evaluated for the ratio female/juvenile and the frequency of males. Altogether our results illustrate that the muscadine-derived resistance based on hardwood cuttings is durable. By contrast, in resistant and reference accessions obtained from in vitro, our data suggest that the increased nematode multiplication might be mainly due to the modification of root architecture consecutive to this propagation method.

scholarly journals RESISTANCE OF POTATO GENOTYPES TO Meloidogyne javanica

2017 ◽  
Vol 30 (2) ◽  
pp. 536-540 ◽  
Author(s):  
JAQUELINE TAVARES SCHAFER ◽  
CESAR BAUER GOMES ◽  
ARIONE DA SILVA PEREIRA ◽  
FERNANDA FERREIRA CRUZ ◽  
DANIELLE RIBEIRO DE BARROS
Keyword(s):  
Potato Cultivar ◽  
Meloidogyne Javanica ◽  
Temperate Climate ◽  
Initial Population ◽  
Nematode Reproduction ◽  
Potato Plants ◽  
Final Population ◽  
Susceptible Control ◽  
Different Levels ◽  
Reproduction Factor

ABSTRACT The objective of this study was to evaluate the resistance of a group of clones and cultivars from the potato breeding program of Embrapa to Meloidogyne javanica. The experiment was conducted at Embrapa Temperate Climate, Pelotas / RS, under greenhouse conditions at temperatures of 25 ± 5°C. Individual potato plants of different genotypes [BRSIPR Bel, BRS F63 (Camila), CL02-05, F23-11-06, F32-02-06, F38-03-07, F189-09-06, F23-24-06 and F22-01-08], kept in pots with sterilized soil were inoculated with 5,000 eggs and J2 of M. javanica, using six replicates per treatment. The susceptible control, potato cultivar BRS Ana was inoculated with the same level of inoculum. Fifty-five days after inoculation, the number of galls on the roots of each plant was determined as well as the number of protuberances caused by nematodes in the different treatments. Then, the roots of each plant were processed for counting the number of eggs and J2, as well as determining the nematode reproduction factor (FR: final population / initial population). All genotypes were susceptible (FR> 1.00) to M. javanica. However, there were different levels of susceptibility among the cultivars tested.

scholarly journals Short-Term Effects of Sublethal Doses of Nematicides on Meloidogyne incognita

2019 ◽  
Vol 109 (9) ◽  
pp. 1605-1613 ◽  
Author(s):  
Catherine L. Wram ◽  
Inga A. Zasada
Keyword(s):  
Population Density ◽  
Meloidogyne Incognita ◽  
Cultivated Plants ◽  
Parasitic Nematodes ◽  
Initial Population ◽  
Plant Parasitic Nematodes ◽  
Water Control ◽  
Effective Doses ◽  
Sublethal Doses ◽  
Plant Parasitic

Meloidogyne species are one of the most important groups of plant-parasitic nematodes globally because of their ability to damage most cultivated plants. Although they are widespread and economically important, there are limited control measures to combat these nematodes. New nonfumigant nematicides have been discovered that have the potential to be widely utilized for the management of plant-parasitic nematodes. Because of the longer half-lives in soil and lower toxicity of new nematicides compared with traditional fumigant and nonfumigant nematicides, understanding how nematodes respond to sublethal doses of nematicides is imperative to understanding whether nematicide resistance has the potential to develop. Characterizing responses of nematodes to sublethal doses will provide the foundation for future work, such as gene expression studies. In this study, the nematicides oxamyl (Vydate), fluazaindolizine (Salibro), fluensulfone (Nimitz), and fluopyram (Velum), were evaluated to understand how sublethal doses affect the fecundity and mobility of Meloidogyne incognita second-stage juveniles (J2). Using a microwell assay system, dose-response curves for each nematicide were established for M. incognita J2. Fluopyram was the most toxic nematicide, with effective doses up to 230 times lower than that of other nematicides. The other nematicides had predicted ED50 values (effective doses that resulted in 50% of the population becoming inactive) of 89.4, 131.7, and 180.6 ppm for oxamyl, fluensulfone, and fluazaindolizine, respectively. The 24-h ED50 of each nematicide was then used in both motility and infectivity assays. The motility and activity of M. incognita J2 exposed to ED50 doses of fluazaindolizine and fluensulfone was significantly reduced, with nematodes initially being motile but eventually becoming inactive. However, the motility of M. incognita J2 exposed to ED50 doses of fluopyram and oxamyl was not different from a water control. In a pot assay, M. incognita J2 exposed to ED50 doses of fluazaindolizine, oxamyl, and fluensulfone were unable to reproduce on tomato, with reproduction factors (RF = final population density/initial population density) of 0 to 0.03. Fluopyram did not reduce reproduction of M. incognita, with a mean RF of 38.7 ± 4.5, which was similar to the RF of 46.3 ± 4.6 for the water control. This study is the first comprehensive evaluation of M. incognita activity, motility, and fecundity after exposure to the traditional nematicide, oxamyl, as well as three new nematicides, fluazaindolizine, fluopyram, and fluensulfone.

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