Population dynamics of plant parasitic nematodes in Queensland pineapple fields and the effects of these nematodes on pineapple production

1993 ◽  
Vol 33 (2) ◽  
pp. 197 ◽  
Author(s):  
GR Stirling ◽  
A Nikulin
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Ratoon Crop ◽  
Original Population ◽  
Ethylene Dibromide ◽  
Nematode Population Density ◽  
Plant Parasitic

Twelve pineapple fields with various densities of root-knot nematode were selected during a ratoon crop. Nematode populations were monitored regularly after the crop was ploughed out. Regardless of the original population density, rootknot nematodes were almost nondetectable at the end of the subsequent 3-6-month fallow intercycle period. In the absence of nematicide treatment there were marked differences between sites in the manner in which rootknot nematodes increased in the newly planted crop. At some sites, they were detectable 9-15 months after planting, whereas at other sites, nematodes were not observed at 15 months. Increases in ratoon crop yield following application of ethylene dibromide or fenamiphos were related to root-knot nematode population density. Significant increases in yield were not obtained at sites where the nematode was not detectable at 15 months. The results suggest that some pineapple growers are needlessly applying nematicides and that nematode diagnostic services should be developed to provide growers with advice on their nematode management programs.

scholarly journals Yield losses caused by plant parasitic nematodes graphical estimation

2019 ◽  
Author(s):  
Nicola Sasanelli ◽  
◽  
Ion Toderas ◽  
Elena Iurcu-Straistaru ◽  
Stefan Rusu ◽  
...  
Keyword(s):  
Population Density ◽  
Relative Yield ◽  
Tolerance Limit ◽  
Parasitic Nematodes ◽  
Soil Nematode ◽  
Yield Losses ◽  
Plant Parasitic Nematodes ◽  
Nematode Population Density ◽  
The Relationship ◽  
Plant Parasitic

Curves for graphical estimation of yield losses caused by plant parasitic nematodes were calculated on the basis of the relationship between soil nematode population density and damage to plants as described by the Seinhort’s equation y = m + (1 – m) z(P-T). By a logarithmic transformation this equation was transformed as y = m + (1 – m) 1.05[(P/-T) + 1] and solved considering values of tolerance limit (T) and the minimum relative yield (m) from the literature. The obtained curves that can be defined “Curves of nematode-pathogenicity” allow a quick and easy evaluation of yield losses for each known crop-nematode relationship.

scholarly journals Toward genetic modification of plant-parasitic nematodes: delivery of macromolecules to adults and expression of exogenous mRNA in second stage juveniles

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  
Keyword(s):  
Food Security ◽  
Genetic Modification ◽  
The Body ◽  
Forward Genetics ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Cyst Nematodes ◽  
Plant Parasitic

Abstract Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.

The role of plant-parasitic nematodes in reducing yield of sugarcane in fine-textured soils in Queensland, Australia

2007 ◽  
Vol 47 (5) ◽  
pp. 620 ◽  
Author(s):  
B. L. Blair ◽  
G. R. Stirling
Keyword(s):  
Growth And Yield ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Lesion Nematode ◽  
Yield Responses ◽  
The Impact ◽  
Stalk Length ◽  
Plant Parasitic

Damage to sugarcane caused by root-knot nematode (Meloidogyne spp.) is well documented in infertile coarse-textured soils, but crop losses have never been assessed in the fine-textured soils on which more than 95% of Australia’s sugarcane is grown. The impact of nematodes in these more fertile soils was assessed by repeatedly applying nematicides (aldicarb and fenamiphos) to plant and ratoon crops in 16 fields, and measuring their effects on nematode populations, sugarcane growth and yield. In untreated plant crops, mid-season population densities of lesion nematode (Pratylenchus zeae), root-knot nematode (M. javanica), stunt nematode (Tylenchorhynchus annulatus), spiral nematode (Helicotylenchus dihystera) and stubby-root nematode (Paratrichodorus minor) averaged 1065, 214, 535, 217 and 103 nematodes/200 mL soil, respectively. Lower mean nematode population densities were recorded in the first ratoon, particularly for root-knot nematode. Nematicides reduced populations of lesion nematode by 66–99% in both plant and ratoon crops, but control of root-knot nematode was inconsistent, particularly in ratoons. Nematicide treatment had a greater impact on shoot and stalk length than on shoot and stalk number. The entire community of pest nematodes appeared to be contributing to lost productivity, but stalk length and final yield responses correlated most consistently with the number of lesion nematodes controlled. Fine roots in nematicide-treated plots were healthier and more numerous than in untreated plots, and this was indicative of the reduced impact of lesion nematode. Yield responses averaged 15.3% in plant crops and 11.6% in ratoons, indicating that nematodes are subtle but significant pests of sugarcane in fine-textured soils. On the basis of these results, plant-parasitic nematodes are conservatively estimated to cost the Australian sugar industry about AU$82 million/annum.

scholarly journals Peach Root-knot Nematode

EDIS ◽  
2018 ◽  
Vol 2018 (4) ◽  
Author(s):  
Mary Ann D. Maquilan ◽  
Ali Sarkhosh ◽  
Donald W. Dickson
Keyword(s):  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
The Subject ◽  
Plant Parasitic

One of the production issues that peach growers in Florida must contend with is plant-parasitic nematodes. One such species is the more recently discovered peach root-knot nematode, Meloidogyne floridensis, which is the subject of this 5-page publication. Written by Mary Ann D. Maquilan, Ali Sarkhosh, and Donald Dickson and published by the UF/IFAS Horticultural Sciences Department, July 2018. http://edis.ifas.ufl.edu/hs1320

scholarly journals Biochemical Analysis Based on Zinc Uptake of Chickpea (Cicer arietinum L.) Varieties Infected by Meloidogyne incognita

2021 ◽  
pp. 186-192
Author(s):  
Pranaya Pradhan ◽  
Dhirendra Kumar Nayak ◽  
Manaswini Mahapatra
Keyword(s):  
Cicer Arietinum ◽  
Zinc Content ◽  
Cost Effective ◽  
Zinc Uptake ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Cicer Arietinum L ◽  
Chickpea Plant ◽  
Plant Parasitic

The significant constraints in Chickpea (Cicer arietinum L.) production hampers a bit more than 14% global yield loss due to plant-parasitic nematodes. Root-knot nematode (Meloidogyne sp.) is an endoparasite and a significant species affecting the chickpea plant. So, the chemical basis of management is more cost-effective, and pest resurgence building is enhanced in the pathogen. So, ecological-based nematode management is requisite, which also is got hampered due to breeding for resistance against such plant-parasitic nematodes. This was the primary reason to conduct this experiment to enhance resistance in the chickpea plants based on Zinc uptake by using bioagent, Pseudomonas fluorescens alone or in combination. where Different treatments including nematode, bacterium, and chemicals were used sustaining the enhancement of disease resistance in chickpea cultivars, RSG 974, GG 5, GNG 2144. Zinc content of chickpea variety GNG 2144 was found the highest in treatment, when only bacterium (P. fluorescens) was inoculated, i.e., 3.14 mg/100g of root followed by GG 5, i.e., 2.79 mg/100g of root and RSG 974 was, i.e., 2.35 mg/100g of root respectively in a descending order. Application of P. fluorescence combined or alone gradually increased the Zn concentration in roots of chickpea plants compared to healthy check followed by chemical treated plants.

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.

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.

Resistance and tolerance of grapevine rootstocks to plant parasitic nematodes in vineyards in north-east Victoria

1989 ◽  
Vol 29 (1) ◽  
pp. 129 ◽  
Author(s):  
M Edwards
Keyword(s):  
Large Population ◽  
Parasitic Nematodes ◽  
Cabernet Sauvignon ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
North East ◽  
Tylenchulus Semipenetrans ◽  
Effect On Yield ◽  
Citrus Nematode ◽  
Plant Parasitic

Three grapevine rootstock trials in North-East Victoria, Australia, were sampled over several summers to determine nematode populations and the resistance or the tolerance of some commonly used winegrape varieties and rootstocks to plant parasitic nematodes. Rootstocks on which nematodes failed to reproduce or reproduced poorly were considered resistant, rootstocks which supported high populations of nematodes with no apparent effect on yield were considered tolerant. Susceptible rootstocks supported high numbers of nematodes and yielded poorly. The varieties studied were: Shiraz, Chardonnay, Cabernet Sauvignon; and the rootstocks were: Harmony, Richter 110, Schwarzmann, ARG No. 1, 5A Teleki, Rupestris du Lot, 5BB Kober, SO4, Ramsey, K5 1-32 and 1202. The plant parasitic nematodes found on the trial sites were root-knot (Meloidogyne javanica (Treub) Chitwood) and citrus (Tylenchulus semipenetrans Cobb) nematodes. Cabernet Sauvignon, Chardonnay, Shiraz and ARG No. 1 were susceptible to the root-knot nematode. Harmony exhibited tolerance to the citrus nematode and was a good host, allowing a large population to build up. Ramsey appeared to be resistant to the citrus nematode, at least in the Cabernet Sauvignon rootstock trial at Wahgunyah.

scholarly journals Construction of artificial microRNA expression vectors for inhibition of Minc16281 gene in root-knot nematode Meloidogyne incognita

2019 ◽  
Vol 18 (4) ◽  
pp. 62-69
Author(s):  
Phong V. Nguyen
Keyword(s):  
Meloidogyne Incognita ◽  
Parasitic Nematode ◽  
Expression Vectors ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Gene Encoding ◽  
Soybean Field ◽  
Genes Encoding ◽  
Plant Parasitic

Effectors have been identified to play a very important role in the parasitism of plant-parasitic nematode. To cope with this type of pathogen, many approaches of silencing genes encoding for effectors have been studied and promise to be an effective tool to create plant varieties resistant to plant-parasitic nematodes. In this study, the Minc16281 gene encoding a pioneer effector with unknown function was determined and cloned from a Meloidogyne incognita population isolated from soybean field (ID: MH315945.1). The nucleotide sequence of this gene showed 97% identity to its homolog in GenBank (ID: JK287445.1) used as the control strain in our research. To generate host-induced gene silencing constructs which can potentially silence the expression of Minc16281 gene, two artificial microRNAs were synthesized based on the miR319a structure of Arabidopsis thaliana and inserted into an expression vector in soybean. These microRNAs can be introduced into soybean to investigate the function of Minc16281 on parasitism of root-knot nematode.

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