Presence Of Root-knot Nematode Research Articles

Comparative biological activity of abamectin formulations on root-knot nematodes (Meloidogyne spp.) infecting cucumber plants: in vivo and in vitro

The root-knot nematodes (Meloidogyne spp.) are considered one of the most destructive diseases in the world. In Egypt, farmers primarily rely on chemical nematicides, which have become costly to control. Currently, abamectin is a bio-based pesticide used as an alternative tool against Meloidogyne spp. on cucumber plants (Cucumis sativus L.). During the current research, four tested abamectin formulations were DIVA (1.8% EW), RIOMECTIN (5% ME), AGRIMEC GOLD (8.4% SC) and ZORO (3.6% EC) compared with two reference nematicides namely, CROP NEMA (5% CS) and TERVIGO (2% SC). The main results showed that, in vitro study elucidated that the most effective formulations of abamectin as a larvicidal were EW with LC50 value of 21.66 µg ml−1. However, in the egg hatching test, the formulations of abamectin SC (2%) and EW were the most effective in reducing egg hatching, with LC50 values of 12.83 and 13.57 µg ml−1. The calculated relative potency values showed diversity depending on the two referenced nematicides. On the other hand, in vivo study, the results indicated that, all tested formulations of abamectin recorded general mean reductions in root galls (23.05–75.23%), egg masses (14.46–65.63%). Moreover, the total population density declined by 39.24–87.08%. Furthermore, the influence of abamectin formulations, in the presence of root-knot nematodes, on the growth of cucumber plants parameters, such as root dry weight, root length, root radius, root surface area, shoot dry weight and shoot height, as well as the content of macro-elements (N, P and K) exhibited varying levels of response.

Interaction Studies Between Meloidogyne Javanica and Fusarium Oxysporum f. Sp. lycopersici (Fol) Race 3 on Different Isolines of Tomato Cv. Tasti Lee.

The Mi gene in tomato confers resistance to Meloidogyne javanica, M. incognita, and M. arenaria, the most common tropical root-knot nematode (RKN) species found in Florida. Fusarium wilt (Fol) is another major problem in Florida tomatoes which may interact with RKN and cause more plant damage. To study the interactions between RKN, Fusarium, and Mi in tomato, two greenhouse experiments were conducted. Both experiments used different isolines (with and without I-3 and Mi genes) of the tomato cultivar Tasti Lee®. In the first experiment, all four isolines were subjected to two levels of RKN (~10,000 eggs/pot and no eggs) and two levels of Fol (1000 cc soil with 1,000 cfu/g at planting and no Fol), both applied at planting. In the second experiment, the two isolines without I-3 were exposed to the same two levels of RKN as described above and three levels of Fol (50 ml Fol with 1×106 cfu/m at planting, at 10 DAT, and no Fol). Fol reduced root-knot infection and reproduction when both Fol and RKN were inoculated at planting but not when Fol was inoculated 10 days later. Plant damage from Fol was exacerbated in the presence of RKN, especially when both pathogens were present at planting. Isolines with I-3 grew better in Fol-inoculated soil but had no effect when Fol and RKN were both present. Isolines with Mi gene reduced RKN infection and reproduction but did not affect plant damage caused by Fol. In summary, while RKN reproduction was reduced in the presence of Fol, the overall plant damage was more severe when both pathogens were present.

Occurrence and Identification of Root-Knot Nematodes on Red Dragon Fruit (Hylocereus polyrhizus) in Hainan, China

The genus Meloidogyne is one of the most economically damaging plant parasitic nematodes on a worldwide basis. To date, only the dragon fruits in Brazil were reported infected by M. javanica or M. incognita in previous surveys. From 2019–2021, we conducted our investigation in 62 orchards from 10 counties of Hainan, which are the main producing areas of dragon fruits in China. The collected roots were visually scored by gall index to evaluate the distribution and severity of diseases caused by Meloidogyne. Then, the isolated nematodes were further confirmed by a combination of morphological and molecular analysis. This survey revealed that the root-knot nematodes were widely distributed in red dragon fruit planting areas in Hainan and caused severe symptoms including stunting, wilting, and yellowing of the stems. The nematode populations were identified as M. enterolobii and M. javanica, among which, M. enterolobii accounted for a larger proportion, 93.9%. To our knowledge, this is the first report of M. enterolobii causing diseases on red dragon fruit. The results obtained from this survey will provide an insight into the presence of root-knot nematodes in dragon fruit plants. Also, these results will raise attention for developing effective management strategies to prevent further spread of root-knot nematodes on dragon fruit in Hainan.

Molecular Diagnosis and Evolutionary Relationship Analysis Of Plant Parasitic Tea Garden Nematodes From Different Tea Estates In Sylhet Region of Bangladesh

Nematodes from plant-parasitic sources are ever-present and incidental to plant growth as well as crop production. The damage of tea gardens caused by nematode is often non-specific and easily confused with symptoms. The present study determined the parasitic and non-parasitic nematodes population in different tea gardens of the Sylhet region by their morphological and partial molecular characterization. Out of 13 tea gardens, it was observed that BTRI, Karimpur, Mathiura, and Tarapur tea garden has the highest number of parasitic and non-parasitic nematodes. After PCR amplification, DNA bands with desired amplicon size were detected by gel electrophoresis. Among thirteen soil samples, nematodes from Malnichara, Karimpur, BTRI, Mathiura , and Finlay had partially confirmed the presence of rootknot nematode (Meloidogyne spp.), root-lesion nematode (Pratylenchus brachyurus), burrowing nematode (Radopholus similis), reniform nematode (Rotylenchulus reniformis) and lance nematode (Hoplolaimus columbus) consequently based on approximately base pair of 1.7, 1.1 and 0.52 kb (different Meloidogyne spp.) 0.52, 0.52, 0.25 and 2.3 kb of specific genes. From evolutionary analysis, it might be said that Meloidogyne species are strongly related with each other making clusters except Meloidogyne natalie where this one is closely related with Hoplolaimus columbus in their evolutionary relationship as remaining others (Rotylenchulus reniformis, Radopholus similis, Pratylenchus brachyurus) are in different clusters in the same clade and this result could be confirmed after sequencing. J. Bio-Sci. 29(1): 101-109, 2021 (June)

Assessment and Management of root knot nematodes through an eco-friendly approach

Root-knot nematode (RKN) is a soil-dwelling microscopic roundworm microorganism. Root-knot nematodes (Meloidogyne spp.) are the most common major pathogens of many crops throughout the world, impacting both the quantity and quality of marketable yields. Root-knot nematode which comes from Meloidogyne species is an obligate, parasitic nematode which can be found in varieties of plants, considered as a host to that particular nematode. Their potential host range encompasses more than 2,000 plant species. The presence of root knot nematode in the crops becomes one of the major problems nowadays because they cause great agriculture loss. Among the many genera of nematodes having some economic impact, Meloidogyne spp. are responsible for a large part of the annual 100 billion dollar losses attributed to nematode damage. This chapter discussed on management of root knot nematode, the symptoms of root knot nematode in different kind of crops.

Physiological changes in Solanum lycopersicum L. in the presence of root-knot nematodes and salicylic acid

Nematodes of the genus Meloidogyne spp. are one of the tomato culture’s main pathogens. According to their soil infestation level, physiological changes may occur. Consequently, it is extremely important to employ given products to minimize their effect. A feasible option is the salicylic acid, a phytohormone that can induce into resistance due to its ability to increase the production level of some pathogenicity proteins. Therefore, the purpose hereof was to assess the effect of salicylic acid on the physiology of tomato plants subject to different populational densities of Meloidogyne javanica. The design employed was one of randomized blocks, in an incomplete factorial scheme, using the Box Central Compound (BCC) matrix with five nematode populational densities (PD) (0; 5815; 20000; 34184; and 40000 eggs per plant) and five salicylic acid doses (0.0; 0.29; 1.0; 1.71; and 2.0 mM), with four repetitions and two plants per experimental patch. The gas exchanges, fluorescence, and chlorophyll levels were evaluated 45 days after the transplant and soil infestation. The data were submitted for analysis of variance through the F test and, in the significance cases, the polynomial regression analysis was performed. For stomatal conductance, a greater reduction was seen at the PD of 21755 eggs per plant, a fact that might have decreased the liquid assimilation of CO2 and the efficiency of carboxylation. The salicylic acid (SA) affected the CO2 liquid assimilation and the efficiency of carboxylation. The infestation of M. javanica in tomato plants negatively affected the gas exchange and the chlorophyll levels because the SA application did not mitigate the negative effect thereof.

Occurrence and control of root knot nematode in crops: A review

Root-knot nematode (RKN) which comes from Meloidogyne species is an obligate, parasitic nematode which can be found in varieties of plants, considered as a host to that particular nematode. Their potential host range encompasses more than 3000 plant species. The presence of RKN in the crops becomes one of the major problems nowadays because they cause great agriculture loss. Among the many genera of nematodes having some economic impact, Meloidogyne spp. are responsible for a large part of the annual 100 billion dollar losses attributed to nematode damage. This review discussed on mechanism of infection of RKN, the presence of RKN in different kind of crops, and the importance of an intergrated approach used in Meloidogyne spp. management strategies. Meloidogyne spp. management strategies.

A preliminary survey of plant parasitic nematodes on carrots in Hai Duong province, Vietnam

Hai Duong province is the largest specialized area on the carrot production in Northern Vietnam. Recently, some papers reported about symptom of plant parasitic nematodes appeared in carrot cultivated areas, that causes damage to carrot production. i.e. both quantity and quality are decreased. Based on results of the survey carried out in 2015 at two carrot planted areas, viz. Cam Giang and Nam Sach, Hai Duong province, 17 plant parasitic nematode species of 11 genera, 8 families and 3 orders of the parasitic nematodes, such as Tylenchida, Dorylaimida and Triplonchida were recorded. There are some differences on the specific composition as well as parasitic density of plant parasitic nematodes betweent carrot in Hai Duong and Lam Dong province. However, in both areas there are four parasitic groups appearred, viz. root-knot nematodes, lesion nematodes, root ectoparasitic nematodes and virrus vector nematodes. The presence of root-knot nematodes, lesion nematodes is related to damaged symptom in carot, such as multiple branched root, fork deformities (55.56%), root-knot (33.33%) and shorted root (5.56%).

English

The effect of composted sawdust at different concentrations (0, 10, 20... 100% v/v in soil) on tomato plant growth and pigments were investigated with or without the presence of root-knot nematode, Meloidogyne javanica at different inoculum levels (0, 1000, 2000, 3000, 4000, 5000) in clay pots (having diameter 30 cm and depth 60 cm). An increase in the composted sawdust concentration in the field soil progressively increased the availability of chlorides, sulphates, carbonates, bicarbonates, P, K, Mg, Mn, Cu, Zn and Fe. However, reverse trend was evaluated in nitrogen content of the soil with gradual increment in sawdust. Different physical properties such as porosity, pH, conductivity, water holding and cation exchange capacity also increased gradually with gradual sawdust amendment in the soil. Sawdust application enhanced the plant growth as well as leaf pigments in both nematode infected as well as non-infected tomato plants, being maximum in the soil containing 30% composted sawdust. Growth and leaf pigments also showed reductions with respect to increase in nematode inoculum density compared to nematode union-culated plants (that is, controls). However, least amount of tomato growth and leaf pigments were found at 3000 nematode inoculum level. Sawdust treatments favorably affect the root invasion by root-knot nematode juveniles (J2 and J3 + J4) and galls up to 30% but adversely affected onward treatments although, a gradual increase in sawdust concentration in the soil would correspondingly decrease the number of egg masses and eggs per egg mass (that is, fecundity) of the root-knot nematodes. All the above said nematode parameters were also improved with all considered nematode inoculum levels but 3000 was the optimum level for them. After visualizing the results, it can be suggested that 30% composted sawdust was the most economical level as it enhances the growth and pigments irrespective of the presence or absence of root-knot nematode. At the same time, it also controls the root-knot nematodes in particularly in 30% onward dust amendments. Keywords: Meloidogyne javanica, nematode,sawdust. African Journal of Biotechnology , Vol 13(41) 4070-4080

Peningkatan Infeksi Patogen Busuk Pangkal pada Bawang Putih oleh Meloidogyne dengan Variasi Kerapatan Inokulum

<p>Fusarium oxysporum f. sp.cepae (FOCe) causing basal rot of garlic is the main obstacle in improving garlic production. The presence of root knot nematode (Meloidogynespp.) is thought to cause an increase in the disease was caused by FOCe. This research aimed to study the effect of the presence of Meloidogyne in increasing the disease severity of basal rot of garlic caused by FOCe and interactions between them. The research was conducted through surveys and experimental procedures. The survey was conducted to obtain preliminary data on the relationship between the disease severity of basal rot of garlic and the infection of Meloidogyne in soil. Experimental study were prepared using a complete randomized block design, with two factors consisting of three levels inoculum density. The first factor was FOCe and the second factor was Meloidogyne spp. The results showed that the presence of Meloidogyne could increase the disease severity of basal rot of garlic</p>

Macrophomina phaseolina – Meloidogyne javanica disease complex in balsam (Impatiens balsamina): a new report

Balsam seedlings were inoculated with root-knot nematode Meloidogyne javanica Race-2 and Macrophomina phaseolina either individually or concomitantly, as well as sequentially with an interval of 15 days between the nematode or fungal inoculations to determine whether the interaction was concomitant or sequential. The greater reduction in plant growth characters was observed in the plants inoculated with M. javanica and M. phaseolina, either concomitantly or sequentially as compared to their individual inoculation. However, the highest reduction in plant growth characters were recorded in the plants inoculated with M. javanica Race-2 15 days prior to M. phaseolina followed by concomitant-inoculated M. javanica Race-2 and M. phaseolina, and M. phaseolina 15 days prior to M. javanica. The number of galls/root system and the reproduction factor of the root-knot nematode was reduced in the presence of root-rot fungus. The intensity of root-rot caused by M. phaseolina increased in the presence of root-knot nematode M. javanica as compared to when M. phaseolina was inoculated individually. Moreover, stem and collar-rot symptoms caused by M. phaseolina appeared only in the presence of root-knot nematode.

Morphological and biochemical responses of five tobacco cultivars to simultaneous infection with Pythium aphanidermatum and Meloidogyne incognita

Five tobacco cultivars responded to Meloidogyne incognita inoculation with a 1.0–3.0 gall index. Inoculation with Pythium aphanidermatum resulted in a 0.33–2.66 root rot index, except cultivar RK-12 P3, which was without symptoms. The root rot symptoms became more severe in the plants concomitantly inoculated with fungus and nematode.The root rot symptoms also developed on cultivar RK-12 P3 in the presence of root-knot nematode. Soil populations of P. aphanidermatum were significantly greater in the presence than absence of M. incognita . Root- knot nematode population, however, showed a reverse trend, being less in the presence of root rot fungus. The fungus and nematode individually reduced the leaf pigments and plant growth of all cultivars except RK-12 P3 (P≤0.05), being greater in concomitantly inoculated compared with single pathogen inoculated plants. Phenol and salicylic acid contents of tobacco leaves gradually increased up to 15–20 days after planting, and thereafter, decreased. The greatest phenol and salicylic acid concentrations were recorded in tobacco plants concomitantly inoculated with the fungus and nematode.

Interactive effect of root-knot nematode, Meloidogyne incognita and root-rot fungus, Rhizoctonia solani, on okra [Abelmoschus esculentus L.

The individual, concomitant and sequential inoculation of second stage juveniles (at 2000 J2/kg soil) of Meloidogyne incognita and Rhizoctonia solani (at 2 g mycelial mat/kg soil) showed significant reduction in plant growth parameters viz. plant length, fresh weight and dry weight as compared to control. The greatest reduction in plant growth parameters was recorded in the plants simultaneously inoculated with M. incognita and R. solani followed by sequential and individual inoculation. In sequential inoculation, plant inoculated with M. incognita 15 days prior to R. solani shows more reduction in comparison to plant inoculated with R. solani 15 days prior to M. incognita. Moreover, the multiplication of nematode and number of galls/root system were significantly reduced in concomitant and sequential inoculation as compared to individual inoculation, whereas the intensity of root-rot/root system caused by R. solani was increased in the presence of root-knot nematode M. incognita as compared to when R. solani was inoculated individually.

290 COMPARING THE EFFICACY OF CHEMICAL CONTROLS FOR ROOT-KNOT NEMATODE ON WATERMELON

Nine treatments, arranged in a RCB design with 4 replications on 20m rows/plot, were all soiled applied and incorporated under black polyethylene mulch, prior to planting. The treatments were: methyl bromide (MB) 98 and 67 & chloropicrin at 168 kgha-1, metham sodium at 17 & 34 1ha-1, oxamyl at 1.6 & 3.21 1ha-1, fosthiazate 6.5 & 13 kgha-1, and a control. Four week-old `Crimson Sweet' watermelon (Citrullus lanatus) transplants were established 3 weeks after chemical applications were made. Soil samples were taken in the plastic row-middle, plastic edge, 30 cm off the plastic edge and 15, 30 & 45 cm deep at each sampling location 3 and 6 weeks after transplanting. The presence of Root-knot Nematode, RKN, (Meloidogyne spp.) was established by using `Mountain Pride' tomato as a bioassay. Fruit size and total yield were recorded and the economic return for each control practice calculated. The 1.6 1ha-1 oxamyl plots yielded 6,832 kgha-1 more than the control which corresponds to a return of $183 for the investment of that control. The 3.2 1ha-1 plots had a yield increase of 7,728 kgha-1 and a return of $103, followed by, in order of yield response, 17 1ha-1 Metham plots, 18,592 kgha-1 & $498, 34 1ha-1 Metham plots, 25,872 & $693, MB 67 plots, 35,952 kgha-1 & $752, and MB 98 plots, 37,072 kgha-1 & $851.