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Cyst-forming nematodes have been known since the second half of the 19th century as one of the causes of "soil fatigue" and highly harmful agricultural pests. In Ukraine, the sugarbeet cyst nematode Heterodera schachtii Schmidt, 1871; cereal cyst nematode H. avenae Wollenweber, 1924; golden potato cyst nematode Globodera rostochiensis Wollenweber, 1923; clover cyst nematode H. trifolii Goffart, 1932; alfalfa cyst nematode H. medicaginis Kirjanova & Krall, 1971; hop cyst nematode H. humuli Filipev, 1934 are currently economically significant species. Their distribution mainly coincides with the traditional cultivation of sugar beets, grain cereals, potatoes, clover, alfalfa and hops. Long-term studies of the impact of abiotic, biotic, and anthropogenic factors on their populations made it possible to identify the dominant species and improve the set of protective measures. Anti-nematode crop rotations are the main limiting factor in preventing mass reproduction of cyst-forming nematodes, provided there is scientifically justified crop rotation. To prevent the mass accumulation of alfalfa and clover cyst-forming nematodes, the maximum share of perennial grasses in crop rotations should not exceed 30% (crops under cover of grain cereals + perennial legumes – one-two-year use); oat nematode – 40% of grain cereals; beet nematode – 20% of Chenopodioideae and cruciferous crops; golden potato nematode – 20% of potatoes (10% susceptible + 10% resistant varieties). The rational saturation of modern crop rotations with intermediate crops makes it possible to reduce the level of crop weediness caused by potential host plants of cyst-forming nematodes and to increase their anti-nematode effectiveness in general. The developed ecologically oriented system of phytosanitary control provides mandatory measures, which must be applied regardless of the level of initial population density, and additional measures specific to each culture and species of cyst-forming nematodes. Considering the current high specialization of crop production, the use of biological preparations in modern systems of integrated plant protection will contribute to the greening of agricultural output. Pre-planting treatment of tubers with metabolic biological preparations (Streptomyces avermitilis) of multifunctional action ensured the achievement of a higher (79.2–91.7%) efficiency of biological cleaning of the soil from the golden potato nematode, compared to the use of only potato-resistant varieties. A logical combination of various anti-nematode measures makes it possible to effectively keep the density of populations at an economically insignificant level and prevent crop yield losses.

A species of Heterodera has been known to parasitise cereals in Australia since the 1930s. It caused significant yield losses across Australia’s cereal growing regions until resistance breeding largely brought it under control, although it still occurs occasionally, especially in South and Western Australia. Australian cereal cyst nematode has long been considered to represent Heterodera avenae. However, in 2002 the name Heterodera australis was proposed for Australian cereal cyst nematode, as it could be distinguished from all non-Australian populations of H. avenae via biochemical and molecular methods. This new species proposal came with speculation that both H. avenae and H. australis might occur in Australia, and that H. australis might represent a native species. The name H. australis has generally not been accepted by Australian scientists, nor the notion that it is native. There remains some uncertainty as to the validity of H. australis and whether more than one species of cereal cyst nematode occur in Australia. Using a molecular barcoding approach (COI, 18S, ITS, 28S) we examined the species composition of cyst nematodes present in soil samples collected between 1989–2023 from Australian cereal growing regions. We find only one species of Heterodera parasitising cereals and, based on phylogenetic analyses, accept the validity of H. australis as the name best representative of this species. We also argue that, based on presently available evidence, H. australis is not native and was most likely introduced into Australia from Asia in the 1850s, rather than from Europe as has been generally assumed. [ABSTRACT FROM AUTHOR]

Root-knot nematode (M. incognita) belonging to the family Heteroderidae are microscopic worm pose significant threat to global agriculture. Because of their parasitic nature and ability to infest a wide variety of plant species, they pose a threatening challenge to farmers. It emphasizes the significance of understanding root-knot nematodes and the need for effective management strategies. The morphological characteristics of various life stages, from eggs to adults, are described, laying the basics for a thorough investigation into their biology. Understanding the root-knot nematode life cycle is critical for developing effective control measures. The interaction of root-knot nematodes with their hosts is a complex process involving molecular and physiological mechanisms. Root-knot nematodes cause a variety of symptoms in infected plants, including root galling, stunted growth, and decreased yield. The pathogenic effects of nematode infestation on various crops, revealing the mechanisms underlying these symptoms and their impact on plant health. The most dangerous plant parasitic nematodes are thought to be Meloidogyne sp. They cause crop losses in vegetable crops all over the world and play a significant role in the widespread use of chemical pesticides. It is widespread in Asia, Southeast Asia and usually occurs in warmer areas. Various management strategies are required to reduce the impact of root-knot nematodes. Cultural practices, biological control methods, chemical interventions, and the development and deployment of resistant plant varieties are all covered in this section. It evaluates the efficacy and long-term viability of each approach, providing insights into integrated pest management strategies. With this review we conclude that there is need for further studies for isolation, distribution and management strategies of root-knot nematode. [ABSTRACT FROM AUTHOR]

The ryegrass cyst nematode, Heterodera mani, is reported from Western Australia for the first time. Cysts were recovered from soil samples collected on a broadacre cropping property near the town of Esperance. The production area is dominated by cereal/oilseed rotation and a species of annual ryegrass (Lolium rigidum) is a common weed issue in these paddocks. Morphometrics of cysts and second stage juveniles (J2s) from the Western Australian population were consistent with data from other reports of this species. Sequences of the mitochondrial cytochrome c oxidase I (COI) gene region were generated and matched those of H. mani from previous reports. Sequences of the large subunit ribosomal RNA (28S rRNA) were produced for H. mani for the first time. Although interspecific variation is relatively low for this gene in the Heterodera avenae species complex, our analyses indicate that 28S gene sequences sufficiently differentiate H. mani from other H. avenae-group members. Lolium rigidum is likely the host for the H. mani population discovered, although this requires further confirmation. [ABSTRACT FROM AUTHOR]

The pitahaya fruit has an exotic appearance, pleasant taste and nutraceutical constituents. This fruit has gained popularity, aiming to increase its acceptance in national and international consumer markets. Since the increase in the planted area, several reports of the association with nematodes have been registered, whose interaction causes plant weakness and, consequently, a decrease in productivity. However, studies on the host suitability of pitahaya and nematode species are scarce in Brazil. In this sense, the present work presents an investigation of the reaction of red pitahaya (Hylocereus undatus) to three phytonematodes species Meloidogyne incognita, Meloidogyne javanica, and Rothylenchulus reniformis. The experiment was carried out in a greenhouse in the experimental field of the Instituto Taquaritinguense de Ensino Superior (ITES), municipality of Taquaritinga, São Paulo state, from seedlings transplanted into 5 L pots containing sterile substrate. The seedlings were inoculated 60 days after transplanting with 548 eggs + J2 per mL for M. incognita, 352 eggs + J2 per mL for M. javanica and 220 eggs + J2 per mL for R. reniformis. After 120 days of inoculation, the roots were processed for extraction of the eggs and determination of the reproduction factor (RF) of the nematodes. Under the conditions evaluated, red pitahaya proved to be resistant to M. incognita and R. reniformis and susceptible to M. javanica. [ABSTRACT FROM AUTHOR]

Summary: The pigeon pea cyst nematode, Heterodera cajani , is an important nematode pest of pigeon pea that is present in all major growing regions of this crop in India and reported from Pakistan, Egypt and Myanmar. In this study, a new real-time PCR assay for detection of H. cajani using a species-specific primer and a TaqMan probe was developed. The primers and a probe were designed to amplify the COI gene fragment. The specificity of the primer-probe set was tested in singleplex or multiplex reactions against target and non-target nematodes. In multiplex real-time PCR experiments with the specific and universal primer-probe sets, the signals were simultaneously observed for COI and D3 of 28S rRNA target genes. The results showed that the real-time PCR assay with species-specific primer and probe was sensitive enough to detect H. cajani DNA extracted from 0.003 egg or second-stage juvenile. [ABSTRACT FROM AUTHOR]

The results revealed that egg hatching and larval mortality of Meloidogyne incognita in culture filtrate of Trichoderma viride and Trichoderma harzianum increased with the increase in the concentration of culture filtrate and time duration. The egg hatching in Trichoderma viride culture filtrate was highest (100.00) in the 5.0% concentration followed by 89.00, 81.50, 72.50, 66.25, 56.75, 53.50, 42.25 and 34.00 at 36 hours and 169.50, 154.25, 142.00, 128.25, 121.25, 95.50, 75.25, 65.50, 42.25 at 72 hrs time duration time in 5, 10, 15, 20, 30, 40, 50, 75, 100% filtrate concentration, respectively. The larval mortality was observed highest 72.25% in 100% concentration of the culture filtrate followed by 4.00, 17.00, 22.00, 42.25, 47.50, 54.50, 63.00, 67.50, and 72.25% at 36 hrs interval and 13.75, 26.00, 41.25, 56.75, 59.75, 66.50, 72.00, 77.75 and 81.00% mortality at 72 hrs in 5, 10, 15, 20, 30, 40, 50, 75 and 100% concentration treatment. In Trichoderma harzianum culture filtrate was recorded highest (82.25) in the 5.0% concentration followed by 72.00, 67.50, 60.25, 54.50, 49.25, 40.75, 31.50 and 24.75 at 36 hrs and 148.00, 136.75, 126.50, 118.00, 99.25, 79.75, 65.50, 52.50, 31.25 at 72 hrs time duration time in 5, 10, 15, 20, 30, 40, 50, 75, 100% filtrate concentration, respectively. The larval mortality was observed highest 86.00% in 100% concentration of the culture filtrate followed by 6.25, 16.75, 23.50, 29.50, 48.75, 58.25, 64.50, 74.00, and 86.00% at 36 hrs interval and 13.25, 32.00, 47.75, 53.50, 64.00, 69.50, 76.25, 84.75 and 93.50% mortality at 72 hrs in 5, 10, 15, 20, 30, 40, 50, 75 and 100% concentration treatment. The % reduction in egg hatching when eggs were exposed to the culture filtrate of Trichoderma viride and Trichoderma harzianum in comparison to the control was recorded 26.72, 35.85, 39.86, 46.32, 51.44, 56.12, 63.69, 71.93 and 77.95 at 36 hrs and 12.81, 19.44, 25.47, 30.48, 41.53, 53.01, 61.41, 69.07 and 81.59 at 72 hrs exposer time in T. harzianum culture filtrate on the other hand in T. viride recorded 10.35, 24.73, 31.07, 38.68, 43.97, 52.00, 54.75, 35.72, 71.25 and 71.25 at 36 hrs and 3.00, 11.73, 18.74, 26.60, 30.61, 45.35, 56.93, 62.51 and 75.82 % at 72 hrs exposer period. [ABSTRACT FROM AUTHOR]

The results revealed that all the treated plots with bioagents and chemical significantly increased the plant growth parameters and reduced root knot nematodes multiplication over untreated check. Pochonia chlamydosporia @ 6 kg/ac was found to be effective in controlling the nematodes and also increase in yield by 78.8% over control which was on par with 8 kg/ac. Vermicompost and Farmyard manure (FYM) were selected as the base medium and the bio control agents were tested for the growth and proliferation in vermicompost and Farmyard manure. Comparatively significant growth and proliferation was observed in vermicompost when compared to FYM. The Pochonia. chlamydosporia colonized vermicompost better than FYM and also the ratio 1:2 recorded the maximum colonization on the 10th day and there was decease on the 15th day. Whereas Purpureocillium lilacinum recorded the maximum colonization in 1:1 ratio on 5th day and there was a decease on 10th day. Application of the bioagent enriched vermicompost significantly increased the yield of the crop. The data on the root colonization of the bioagent and its parasitization of the nematode eggs indicate that the strain of P. chlamydosporia is rhizosphere competent. [ABSTRACT FROM AUTHOR]

The identification and phylogenetic relationships of potato cyst nematodes (PCN) were studied to assess the potential value of geographical distribution information for integrated pest management of potato production in Portugal. This research focused on PCN species, Globodera pallida and Globodera rostochiensis. From 2013 until 2019, 748 soil samples from the rhizosphere of different potato cultivars were surveyed in the Portuguese mainland to detect and identify both species and track their location. PCN are widespread invasive species throughout Portugal. In fact, during the survey period an incidence of 22.5% was estimated for the tested samples. The patterns of infestation vary among regions, increasing from south to north, where PCN were first detected. Currently, both species are present in all potato producing regions of the country, with a greater incidence of G. pallida. Phytosanitary control measures are influencing to the observed results. The use of potato cultivars resistant to G. rostochiensis led to a decrease of this species but had no influence on G. pallida detections, which continues its reproduction freely since there are no effective resistant cultivars for this species. The relationship between the presence, infestation rate, spread and geographical distribution of PCN is discussed in terms of behavioral responses of the potato cultivars and the implications for developing new integrated crop protection measures.

Summary: Whilst investigating plant-parasitic nematodes in Urmia City, West Azerbaijan, Iran, soil samples were collected from the rhizosphere of willow trees (Salix babylonica) known to have a population of cyst nematodes. Morphological, numerical and molecular approaches revealed that this population represented the willow cyst nematode, Heterodera salixophila , the first report of this species from Iran. Reproduction of the nematode on S. babylonica was confirmed by inoculating 5000 viable eggs and second-stage juveniles (J2) per kg soil on 2-year-old seedlings of S. babylonica grown in pots containing sterilised soil and incubated under glasshouse conditions. Principal Component Analysis (PCA) and hierarchical cluster analysis of morphometric characters of J2 and vulval plates of species within the Humuli group supported the separation of H. salixophila from other species in this group. In the ITS-rRNA phylogenetic tree, the Iranian population of H. salixophila formed a cluster with two other populations of the species from Belgium and Ukraine, while in the D2-D3 expansion segments of the 28S rRNA tree, it grouped with a population from Belgium as a basal clade in the Humuli group. [ABSTRACT FROM AUTHOR]

The identification and phylogenetic relationships of potato cyst nematodes (PCN) were studied to assess the potential value of geographical distribution information for integrated pest management of potato production in Portugal. This research focused on PCN species, Globodera pallida and Globodera rostochiensis. From 2013 until 2019, 748 soil samples from the rhizosphere of different potato cultivars were surveyed in the Portuguese mainland to detect and identify both species and track their location. PCN are widespread invasive species throughout Portugal. In fact, during the survey period an incidence of 22.5% was estimated for the tested samples. The patterns of infestation vary among regions, increasing from south to north, where PCN were first detected. Currently, both species are present in all potato producing regions of the country, with a greater incidence of G. pallida. Phytosanitary control measures are influencing to the observed results. The use of potato cultivars resistant to G. rostochiensis led to a decrease of this species but had no influence on G. pallida detections, which continues its reproduction freely since there are no effective resistant cultivars for this species. The relationship between the presence, infestation rate, spread and geographical distribution of PCN is discussed in terms of behavioral responses of the potato cultivars and the implications for developing new integrated crop protection measures. [ABSTRACT FROM AUTHOR]

The species structure, morphological peculiarities and economic importance of the dominant cyst nematodes from cultural and natural phytocenosis of Ukraine are analyzed.

На Дальнем Востоке России отмечен 21 вид седентарных нематод из групп цистообразующих, галловых и тиленхулидных. 7 видов выявлено в агроценозах, 1 вид – в Ботаническом саду.

На Дальнем Востоке России отмечен 21 вид седентарных нематод из 2 надсемейств и 4 семейств – Heteroderidae, Melodogynidae, Tylenchulidae и Sphaeronematidae. Из группы цистообразующих нематод семейства Heteroderidae на Дальнем Востоке России известно 13 видов, из них 9 видов отмечено в естественных ценозах. В группе галловых нематод – 5 видов, из которых 2 вида встречаются в естественных ценозах. Два последних семейства включают в себя по 1 виду и на Дальнем Востоке отмечены только в естественных ценозах.

• Cyst nematodes deliver effector proteins into host cells to manipulate cellular processes and establish a metabolically hyperactive feeding site. The novel 30D08 effector protein is produced in the dorsal gland of parasitic juveniles, but its function has remained unknown. • We demonstrate that expression of 30D08 contributes to nematode parasitism, the protein is packaged into secretory granules and it is targeted to the plant nucleus where it interacts with SMU2 (homolog of suppressor of mec-8 and unc-52 2), an auxiliary spliceosomal protein. • We show that SMU2 is expressed in feeding sites and an smu2 mutant is less susceptible to nematode infection. In Arabidopsis expressing 30D08 under the SMU2 promoter, several genes were found to be alternatively spliced and the most abundant functional classes represented among differentially expressed genes were involved in RNA processing, transcription and binding, as well as in development, and hormone and secondary metabolism, representing key cellular processes known to be important for feeding site formation. • In conclusion, we demonstrated that the 30D08 effector is secreted from the nematode and targeted to the plant nucleus where its interaction with a host auxiliary spliceosomal protein may alter the pre-mRNA splicing and expression of a subset of genes important for feeding site formation. [ABSTRACT FROM AUTHOR]

When nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in plant-nematode interactions remain unexplored. Here, we characterized the role of a group of cell wall receptor proteins in Arabidopsis, designated as polygalacturonase-inhibiting proteins (PGIPs), during infection with the cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. PGIPs are encoded by a family of two genes in Arabidopsis, and are involved in the formation of active OG elicitors. Our results show that PGIP gene expression is strongly induced in response to cyst nematode invasion of roots. Analyses of loss-of-function mutants and overexpression lines revealed that PGIP1 expression attenuates infection of host roots by cyst nematodes, but not root-knot nematodes. The PGIP1- mediated attenuation of cyst nematode infection involves the activation of plant camalexin and indole-glucosinolate pathways. These combined results provide new insights into the molecular mechanisms underlying plant damage perception and response pathways during infection by cyst and root-knot nematodes, and establishes the function of PGIP in plant resistance to cyst nematodes. [ABSTRACT FROM AUTHOR]

The cystoid sedentary nematodes of the Heteroderidae include more than 30 recognised species belonging to from nine to 11 genera, depending on the opinion of the authority. In the present study, we collected nematode populations of species belonging to some of these genera, as well as other cyst-forming species from different locations in the USA, Vietnam, Germany and Russia. The populations of cystoid nematodes represent seven valid species, Atalodera carolynae, Cryphodera sinensis, Meloidodera astonei, M. floridensis, M. mexicana, M. sikhotealiniensis, Rhizonemella sequoiae, two unidentified species of Atalodera, six unidentified species of Cryphodera, and three putative new species of Rhizonemella. We also obtained samples of cyst-forming nematodes that include an unidentified species of Betulodera from California, and Heterodera guangdongensis from Vietnam. A population of Rotylenchulus sp. from Arizona, intercepted in Florida, and a population of an unidentified species of Verutus from Germany were also added to this study. All of these populations were characterised using sequences of the D2-D3 of 28S rRNA, ITS rRNA or mitochondrial COI genes. A total of 89 new sequences were obtained from these analyses. Phylogenetic relationships within the family Heteroderidae were reconstructed based on the D2-D3 of 28S rRNA, ITS rRNA and mitochondrial COI gene sequences. Results revealed that the subfamily Ataloderinae was paraphyletic. Ekphymatodera thomasoni, a non-cyst-forming species, clustered with the cyst-forming nematodes. Representatives of the subfamily Verutinae formed clades within Heteroderidae. The genus Meloidodera was non-monophyletic and distributed within two clades: i) M. sikhotealiniensis and Cryphodera spp. from Asia and Europe; and ii) M. astonei, M. floridensis and M. mexicana from North America. Based on comparative molecular analysis Meloidodera alni syn. n. is proposed as a junior synonym of M. sikhotealiniensis. Problems of taxonomy and phylogeography of cystoid nematodes are also discussed. [ABSTRACT FROM AUTHOR]

The potato cyst nematodes (PCN) Globodera rostochiensis and G. pallida pose one of the greatest threats to potato crops worldwide and are subject to strict quarantine regulations in many countries. The identification of these Globodera species based on morphology may be ambiguous due to the variability of the main morphological features and the overlapping of the standard parameters in these two species; thus, confirmation via molecular methods is recommended. Multiplex PCR with speciesspecific primers (ITS5/PITSp4 + PITSr3) allows both species to be distinguished. However, despite the development of molecular identification methods, the morphological approach remains useful as a complementary diagnostic technique. In this work, we report results of morphological and molecular analyses that were carried out in two Globodera species from Portuguese potato fields. The average morphometric values of 40 cysts and 40 second-stage juveniles were generally within the expected ranges for G. pallida and G. rostochiensis with some variations noted. Molecular analysis with multiplex PCR confirmed the morphometric identification. The present results confirmed the occurrence of two potato cyst nematode species, G. rostochiensis and G. pallida. Surprisingly, the analysis of soils from Portuguese potato fields detected a greater number of samples infested with G. pallida, which is contrary to expectation as G. rostochiensis has been considered the most widespread species in Portugal. The distinction between the two species is therefore essential in order to detect their presence in the country with a view to re-evaluating the control measures implemented so far and adopting more effective practices. [ABSTRACT FROM AUTHOR]

A new cyst nematode, herein described as Globodera sandveldensis n. sp., was found in the Sandveld, Western Cape Province, South Africa. As the host plant of G. sandveldensis n. sp. is currently unknown, the species is represented by cysts and second-stage juveniles (J2) only. The J2 are characterised by a well developed stylet of 26.4 (24.8-28.5) µm with rounded to anteriorly flattened knobs. The distance from the dorsal pharyngeal gland outlet to the stylet knobs is 4.5 (2.4-7.2) µm. The tail is 64 (56-77) µm long and the length of the hyaline region is 33 (22-39) µm. The cysts are characterised by their ovate to spherical shape, short neck, and the presence of subcuticular punctations and bullae or vulval bodies. Six to 14 cuticular ridges/lines are present on the outer surface of the cyst between the anus and vulval basin. Granek's ratio is 1.7 (0.9-3.0), the vulval basin diam. is 20.4 (13.1-34.6) µm and the distance between vulval basin and anus is 33.5 (19.7-54.0) µm. Phylogenetic relationships with other species of the genus, inferred from ITS-rDNA sequences, indicate that G. sandveldensis n. sp. is included in the clade of Globodera sp. that parasitise non-solanaceous plants and is closely related to unidentified Globodera spp. from Portugal, G. millefolii, and G. artemisiae. [ABSTRACT FROM AUTHOR]

Histological studies were conducted on host plants infected by three species of nematodes of the Heteroderidae (Cactodera rosae, Globodera mexicana, and Meloidodera astonei). Cactodera rosae established a syncytium, which extended into the cortex, pericycle, phloem, and cambium of Amaranthus hybridus roots. The syncytial cells showed dense cytoplasm and hypertrophied nuclei and nucleoli. In Solanum rostratum roots, G. mexicana induced a syncytium that expanded from the pericycle into the stele incorporating phloematic elements and interfascicular cambial cells. The affected cells had dense cytoplasm, hypertrophied nuclei and nucleoli, and were surrounded by hyperplastic vascular parenchyma tissue. Females of M. astonei induced an uninucleate giant cell in the pericycle of S. rostratum roots. The giant cell, which had a dense cytoplasm and a hypertrophied nucleus, expanded in the tissues of the stele and especially in the secondary phloem. The cells of vascular parenchyma and secondary phloem tissues were hyperplastic. These anatomical changes are in agreement with those of other species of these genera reported in the literature. [ABSTRACT FROM AUTHOR]

The fungus Trichoderma harzianum strain ThzID1-M3 isolated in the Palouse region of the state of Idaho and transformed to express green fluorescent protein (GFP) was used as a biomarker to study the biological control processes of the potato cyst nematode Globodera pallida . Experiments were conducted to evaluate the effect of T. harzianum ThzID1-M3 on G. pallida infection and reproduction at 45 and 75 days after inoculation respectively; and to observe, through microscopy rhizosphere chamber, the colonization of G. pallida second-stage juveniles and potato rhizoplane by T. harzianum ThzID1-M3 10 days after inoculation. Significant reduction of G. pallida infection in potato roots was observed when soil was amended with T. harzianum ThzID1-M3. Globodera pallida cysts recovered from soil and G. pallida reproduction rate were significantly reduced by 49% and 60% respectively, when soil was amended with T. harzianum ThzID1-M3 compared to the non-amended soil. Microscopic observations showed that T. harzianum ThzID1-M3 colonized G. pallida second-stage juveniles and cysts, and proliferated in the rhizoplane and rhizosphere of potato. To our knowledge, this is the first report on the study of Trichoderma spp. marked with GFP against a potato cyst nematode. The use of GFP-tagged T. harzianum has the potential to monitor the biological control processes of G. pallida and the tools advanced in this study should facilitate the design of novel strategies to control this economically important nematode pest of potato. [ABSTRACT FROM AUTHOR]

Plant parasitic nematodes (PPNs) are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants. [ABSTRACT FROM AUTHOR]

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Cereal cyst nematodes (Heterodera avenae and H.filipjevi) and root lesion nematodes (Pratylenchus spp.) have been found to infect cereals in 16 provinces of China. To develop a nematicide that effectively controls nematodes, two novel chemical products, methylene bis thiocyanate (MBT) and MBT + thiamethoxam (MTT); four common pesticides, fipronil + chlorpyrifos (FIC), emamectin benzoate, imidacloprid, and Bacillus thuringiensis; and one fungicide, iprodione, were tested as seed coatings for the control of cereal cysts and root lesion nematodes from 2013 to 2015. Wheat seeds were treated with these seven seed coatings before sowing, and changes in the numbers of Heterodera spp. and Pratylenchus spp. were recorded during three different growth stages. Wheat yields were also compared after harvest. All treatments reduced the numbers of Pratylenchus in wheat and of cysts and eggs of Heterodera in the soil compared with the untreated control. Among the treatments, application of MTT or FIC was more effective than that of the other treatments for nematode control, and the other treatments had similar effects. The results of this study have demonstrated that MTT and FIC applied as seed treatments effectively reduce the number of cysts, inhibit the reproduction of Heterodera and Pratylenchus, and enhance wheat yields. MTT and FIC are thus suitable for controlling nematodes on wheat under natural field conditions. [ABSTRACT FROM AUTHOR]

As nematodes cause great damage to Brazilian coffee production, effective methods to control these parasites are necessary. In a previous work Allium cepa L., Cajanus cajan (L.) Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam.) Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. and Coffea arabica L. produced active substances against Meloidogyne exigua Goeldi, a nematode widely disseminated through Brazilian coffee fields. Thus, aqueous extracts of such plants, collected in a different season from that of the previous work, as well as crude metabolites produced in liquid medium by Fusarium moniliforme Shelden and Cylindrocarpon magnusianum (Sacc.) Woll., were submitted to in vitro assays with M. exigua second-stage juveniles (J2). All plants and fungi produced active substances against J2. Therefore, their metabolites were applied to six-month-old coffee plants inoculated with M. exigua. After 90 days in a greenhouse, those samples obtained from A. cepa, L. leucocephala, R. graveolens and F. moniliforme inhibited the production of galls and eggs by M. exigua, demonstrating potential to control such parasite.Os nematóides acarretam grandes perdas aos produtores brasileiros de café, sendo necessário o desenvolvimento de métodos eficientes para o seu controle. Em trabalho anterior, Allium cepa L., Cajanus cajan (L.) Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam.) Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. e Coffea arabica L. produziram substâncias ativas contra o nematóide Meloidogyne exigua Goeldi, que é amplamente disseminado pelos cafezais brasileiros. Dando continuidade a esse trabalho, extratos aquosos das plantas mencionadas, coletadas em época diferente daquela mencionada no trabalho anterior, bem como metabólitos na forma bruta de Fusarium moniliforme Shelden e Cylindrocarpon magnusianum (Sacc.) Woll., produzidos em meio de cultura líquido, foram submetidos a testes in vitro com juvenis do segundo estádio (J2) de M. exigua. Todas as plantas e fungos produziram substâncias ativas contra J2. Portanto, seus metabólitos foram aplicados em mudas de café de seis meses de idade, inoculadas com M. exigua. Após 90 dias em casa de vegetação, verificou-se que os materiais oriundos de A. cepa, L. leucocephala, R. graveolens e F. moniliforme inibiram a produção de ovos e de galhas por M. exigua, demonstrando potencial para o controle de tal parasita.

Root-knot nematodes, Meloidogyne spp., cause huge economic losses worldwide. Currently, three Meloidogyne spp. are present on the quarantine A2 list of EPPO, M. chitwoodi, M. fallax and M. enterolobii. As a quarantine organism, M. fallax has been detected in England and Northern Ireland on sport turf in 2011, and in England on leek in 2013. However, its presence in Ireland has probably been overlooked since 1965, when Mr. John F. Moore and Dr. Mary T. Franklin had detected a new Meloidogyne species for that time. While the relevant data was recorded and a preliminary manuscript describing the species was prepared but never submitted for publication, and together with the original slides, pictures and drawings, it was restudied recently. We compared the population of Irish Meloidogyne sp. to other similar Meloidogyne spp. Careful observation and comparison shows that it belongs to M. fallax. The characters found to be common for Irish Meloidogyne sp. and M. fallax are female stylet length (14.6 μm) with oval to rounded basal knobs, oval shaped perineal pattern with moderately high dorsal arch, slender stylet in males (18.5 μm) with set off and rounded basal knobs, slightly set off male head with one post-labial annule and incomplete transverse incisures, and second-stage juveniles with large and rounded stylet basal knobs, and a gradually tapering tail (46.9 μm) with a broadly rounded tip and a clearly delimitated smooth hyaline part sometimes marked by constrictions (12.9 μm). The host test and gall formation also correspond to M. fallax. The identification could not be additionally supported by molecular analysis, as we were unable to extract DNA from the old permanent slides. Nevertheless, our study reveals that the Meloidogyne species detected in Ireland in 1965 belongs to M. fallax. [ABSTRACT FROM AUTHOR]

A new soybean cyst nematode Heterodera sojae n. sp. was found from the roots of soybean plants in Korea. Cysts of H. sojae n. sp. appeared more round, shining, and darker than that of H. glycines. Morphologically, H. sojae n. sp. differed from H. glycines by fenestra length (23.5-54.2 μm vs. 30-70 μm), vulval silt length (9.0-24.4 μm vs. 43-60 μm), tail length of J2 (54.3-74.8 μm vs. 40-61 μm), and hyaline part of J2 (32.6-46.3 μmvs. 20-30 μm). It is distinguished from H. elachista by larger cyst (513.4-778.3 μm3 343.4-567.1 μm vs. 350-560 μm 3 250-450 μm) and longer stylet length of J2 (23.8-25.3 μm vs. 17-19 μm). Molecular analysis of rRNA large subunit (LSU) D2-D3 segments and ITS gene sequence shows that H. sojae n. sp. is more close to rice cyst nematode H. elachista than H. glycines. Heterodera sojae n. sp. was widely distributed in Korea. It was found from soybean fields of all three provinces sampled. [ABSTRACT FROM AUTHOR]

Background: The evolution of animal mitochondrial (mt) genomes has resulted in a highly conserved structure: a single compact circular chromosome approximately 14 to 20 kb long. Within the last two decades exceptions to this conserved structure, such as the division of the genome into multiple chromosomes, have been reported in a diverse set of metazoans. We report on the two circle multipartite mt genome of a newly described cyst nematode, Globodera ellingtonae. Results: The G. ellingtonae mt genome was found to be comprised of two circles, each larger than any other multipartite circular mt chromosome yet reported, and both were larger than the single mt circle of the model nematode Caenorhabditis elegans. The genetic content of the genome was disproportionately divided between the two circles, although they shared a ~6.5 kb non-coding region. The 17.8 kb circle (mtDNA-I) contained ten protein-coding genes and two tRNA genes, whereas the 14.4 kb circle (mtDNA-II) contained two protein-coding genes, 20 tRNA genes and both rRNA genes. Perhaps correlated with this division of genetic content, the copy number of mtDNA-II was more than four-fold that of mtDNA-I in individual nematodes. The difference in copy number increased between second-stage and fourth-stage juveniles. Conclusions: The segregation of gene types to different mt circles in G. ellingtonae could provide benefit by localizing gene functional types to independent transcriptional units. This is the first report of both two-circle and several-circle mt genomes within a single genus. The differential copy number associated with this multipartite mt organization could provide a model system for deconstructing mechanisms regulating mtDNA copy number both in somatic cells and during germline development. [ABSTRACT FROM AUTHOR]

Summary -- A significant portion of the Cerrado (Brazilian savanna) has been replaced by major crops such as soybean. This may reveal populations of nematodes with different genetic backgrounds compared to cultivated fields. The objectives of this study were to evaluate the genetic variability and aggressiveness of isolates of Meloidogyne spp., contrasting nematodes from preserved areas of the Cerrado with those originating from cultivated soybean fields. Cluster analysis separated isolates of Meloidogyne spp. and isolates from Cerrado and soybean but did not separate an aggressive Meloidogyne morocciensis isolate. The aggressiveness of six selected populations of Meloidogyne spp. from Cerrado and soybean against soybean cultivars was evaluated. Results showed that populations of M. javanica and M. incognita from Cerrado and soybean showed similar aggressiveness. However, for M. morocciensis, the population from soybean was much more aggressive than the one from Cerrado. Aggressiveness is a very intriguing subject that needs special attention for future research in nematology. [ABSTRACT FROM AUTHOR]

Chilli pepper is an important vegetable in the diet of Ghanaians but there are some constraints militating against increased production notable among which is nematode infestation. A study was therefore carried out at the plant house of the Faculty of Agriculture, University for Development Studies, Nyankpala to investigate the efficacy of neem products against root-knot nematode of chilli pepper (Capsicum annumL.). The treatments which included 20 g neem leaf powder, 20 g neem cake, 20 g neem seed powder and control were arranged in a completely randomised design with four replications. Neem products significantly reduced (p < 0.05) nematode population, with 20 g of neem leaf powder recording the highest reduction. Similarly, plants treated with neem leaf powder produced a significantly lower (p < 0.05) number of root galls compared to the other treatments. Neem leaf powder could be used as a nematicide for nematodes control as a replacement for synthetic nematicides. [ABSTRACT FROM PUBLISHER]

Published data on the presence or absence of phasmids in males of Heteroderidae species are compiled and critically reviewed. Based mainly on results of previous SEM studies and complemented by light microscopy using DIC optics, the conclusion is drawn that male phasmids appear to be absent in all species of the genera assigned to the subfamilies Heteroderinae and Ataloderinae, but present and often distinct in the Meloidoderinae genera Cryphodera and Meloidodera. The presence of male phasmids is considered as ancestral, and loss of phasmids as a derived character. [ABSTRACT FROM AUTHOR]

Published data on the presence or absence of phasmids in males of Heteroderidae species are compiled and critically reviewed. Based mainly on results of previous SEM studies and complemented by light microscopy using DIC optics, the conclusion is drawn that male phasmids appear to be absent in all species of the genera assigned to the subfamilies Heteroderinae and Ataloderinae, but present and often distinct in theMeloidoderinae genera Cryphodera and Meloidodera. The presence of male phasmids is considered as ancestral, and loss of phasmids as a derived character. [ABSTRACT FROM AUTHOR]