Incognita Race Research Articles

A Comparison Between Meloidogyne floridensis and M. incognita from California on Susceptible and Resistant Sweetpotato Cultivars.

The reproduction and ability to cause root-galling of a California isolate of the peach root-knot nematode Meloidogyne floridensis was evaluated on seven sweetpotato (Ipomea batatas) cultivars and compared with an M. incognita race 3 and an M. incognita Mi-gene resistance-breaking isolate. The susceptible tomato (Solanum lycopersicum) cultivar Daniela and the Mi-gene-carrying resistant cultivar Celebrity were included as controls. Repeated trials were done in pots in a nematode-quarantine greenhouse at the University of California, Riverside. The three Meloidogyne isolates reproduced equally well on susceptible tomato. On Mi-gene resistant tomato, the reproduction and root-galling by M. floridensis was intermediate between the avirulent M. incognita race 3 and the resistance-breaking M. incognita isolate. The sweetpotato cultivars 'Beauregard' and 'Diane' were excellent hosts for all three Meloidogyne isolates. Cultivars Bellevue, Burgundy, and Covington were resistant to these isolates. The cultivars Bonita and Murasaki-29 were hosts for the M. floridensis and the resistance-breaking M. incognita isolate, which allowed an increase in nematode levels, but they were poor hosts, resulting in a decrease in nematode levels for the M. incognita race 3 isolate. The study showed that M. floridensis can reproduce on tomato and some sweetpotato cultivars that are considered resistant to M. incognita.

The activity of leaf extracts, fractions, and isolated compounds from Ptaeroxylon obliquum against nine phytopathogenic fungi and the nematode Meloidogyne incognita

Phytopathogenic fungi and nematodes cause great losses in economically important crops and food production especially in developing countries. To minimize the use of fungicides and nematicides, researchers have concentrated on the use of natural products for crop disease prevention or control. The aim of the study was to investigate the antifungal activity of Ptaeroxylon obliquum leaf extracts, fractions, and isolated compounds (obliquumol and a mixture of lupeol and β-amyrin) and nematocidal activity of fractions (hexane, chloroform and 30% water in methanol and the isolated compounds) on Meloidogyne incognita. Nine phytopathogenic fungi (Aspergillus niger, A. parasiticus, Colletotrichum gloeosporioides, Fusarium oxysporum, Penicillium digitatum, P. expansum, P. italicum, P. janthinellum, and Rhizoctonia solani) were used for testing and nematocidal activity was determined on motility of plant parasitic nematode Meloidogyne incognita race 2 juveniles. Serial microdilution test was utilized to determine the minimum inhibitory concentration (MIC) of each sample against the fungus. Motility tests was done on the second-stage juveniles (J2s) of M. incognita. The most susceptible phytopathogenic fungal species to the acetone crude leaf extracts were A. niger, C. gloeosporioides and P. digitatum with MIC of 80 μg/ml which is considered pharmacological significant. Rhizoctonia solani was the most susceptible fungus against obliquumol and, lupeol and β-amyrin mixture with MIC values of 8 μg/ml and 16 μg/ml respectively. Lupeol & β-amyrin mixture had good activity on juvenile motility at high concentrations used which was significantly high (p ≤ 0.05) after 24 h, further incubation resulted in temporary paralysis at lower concentrations. Fractions and obliquumol showed good activity after 48 h, stable paralysis was observed up to 72 h. The extracts and isolated compounds may be useful as fungicides if the in vitro results can be confirmed under field conditions at levels not toxic to beneficial soil organisms.

Evaluation of Weed Species for Host Status to the Root-Knot Nematodes Meloidogyne enterolobii and M. incognita Race 4.

Weeds that compete with valuable crops can also host plant-parasitic nematodes, acting as a source of nematode inoculum in a field and further damaging crops. The host status of 10 weed species commonly found in North Carolina, USA, was determined for the root-knot nematodes Meloidogyne enterolobii and M. incognita race 4 in the greenhouse. Each weed species was challenged with 5,000 eggs/plant of either M. enterolobii or M. incognita race 4, with five replicate plants per treatment in two separate greenhouse trials. Root galling severity and total number of nematode eggs per root system were recorded 60 days after inoculation. Reproduction factor (Rf = final nematode population/initial nematode population) was calculated to determine the host status of each weed species to M. enterolobii and M. incognita race 4. Four weed species (Datura stramonium, Digitaria sanguinalis, Senna obtusifolia, and Cyperus esculentus) were poor hosts (Rf < 1) to both nematode species, and roots of these weed plants did not display galling. Four weed species (Ipomoea hederacea, Amaranthus palmeri, Portulaca pilosa, and Ipomoea lacunosa) were hosts (Rf > 1) to both nematode species, and all had observable root gall formation. Sida rhombifolia and Cyperus rotundus were poor hosts to M. enterolobii but susceptible hosts to M. incognita. This study documents a differential host status of some common weeds to M. enterolobii and M. incognita race 4, and these results highlight the necessity of managing root-knot nematodes through controlling weeds in order to protect valuable crops.

Host status of melon, carrot, and Meloidogyne incognita-susceptible and -resistant cotton, cowpea, pepper, and tomato for M. floridensis from California.

The host status of carrot, melon, and susceptible and resistant cultivars of tomato, cotton, cowpea, and pepper for a California isolate of the peach root-knot nematode Meloidogyne floridensis was determined in greenhouse pot experiments. It was compared to a race 3 isolate of M. incognita. Melon was an excellent host for both isolates and roots were heavily galled after the 8-week trial. Carrot was a host for M. incognita, but a poor host for M. floridensis, although both isolates caused similar levels of galling. Susceptible cotton was a good host for M. incognita race 3, but a poor host for M. floridensis. Susceptible tomato, cowpea, and pepper were good hosts for both isolates. The M. incognita resistance in tomato and pepper was broken by M. floridensis. Resistant cowpea was a maintenance host as population levels of M. floridensis remained virtually unchanged over the trial period. We conclude that M. floridensis poses a risk to some important vegetable crops in California, as it reproduces on most vegetable crops, including some cultivars that are resistant to M. incognita. On susceptible crops, the reproduction of M. floridensis was always significantly less than that of M. incognita, and we hypothesize that in mixed species field populations, M. incognita will outcompete M. floridensis. This study demonstrates that efforts to limit the spread and prevent further introductions of M. floridensis in California are important to maintain the effectiveness of plant resistance as a nematode management strategy in vegetable crops.

Detection of Root-Knot Nematode Species and Races in Kahramanmaraş Province, Türkiye

Root-knot nematodes (Meloidogyne spp.) are organisms that spread over large areas and cause economic damage to vegetables. In this study, root-knot nematode populations obtained from vegetable growing areas of Kahramanmaraş province were identified. Overall, 132 root samples were taken from the vegetable crop fields. Root-knot nematode was detected in 25 of the collected samples and their diagnosis was determined based on biochemical (esterase isoenzyme phenotype), perineal pattern, and molecular methods. The race determination of root-knot nematodes was made according to the North Carolina Differential Host Test. Results showed that while Meloidogyne incognita was detected in Andırın, Onikişubat, Dulkadiroğlu, Türkoğlu, and Ekinözü districts of Kahramanmaraş, both M. incognita and M. javanica were found in Beyoğlu of Türkoğlu. This is the first report of M. javanica infection in Kahramanmaraş. Races of root-knot nematodes were determined as M. incognita race 1, race 2 and M. javanica race 2.

Sensitivity of Meloidogyne incognita, Fusarium oxysporum f. sp. niveum, and Stagonosporopsis citrulli to Succinate Dehydrogenase Inhibitors Used for Control of Watermelon Diseases.

Watermelon is affected by diseases such as Fusarium wilt, gummy stem blight, and root-knot nematode (RKN). Succinate dehydrogenase inhibitors (SDHIs) with potential fungicide and nematicide activity provide the opportunity to control multiple diseases with one compound. In this study, we aimed to determine the sensitivity of Meloidogyne incognita race 4 (MI4), Fusarium oxysporum f. sp. niveum (FON), and Stagonosporopsis citrulli (SCIT) to existing SDHIs: benzovindiflupyr, fluopyram, cyclobutrifluram, and pydiflumetofen. All SDHIs had fungicidal activity against 19 SCIT isolates in mycelial growth assays, but isolates were most sensitive to pydiflumetofen (median EC50 = 0.41 μg/ml). Most of the 50 FON isolates tested were sensitive to cyclobutrifluram for mycelial growth (median EC50 = 4.04 μg/ml) and conidial germination (median EC50 = 0.2 μg/ml) assays but were not sensitive to fluopyram. MI4 was most sensitive to cyclobutrifluram for egg hatch (mean EC50 = 0.0019 μg/ml) and J2 motility (mean EC50 = 1.16 μg/ml) assays but was not sensitive to pydiflumetofen. Significant positive correlations between the sensitivity of SCIT (mycelial growth) and FON (mycelial growth and conidial germination) for cyclobutrifluram and benzovindiflupyr (SCIT r = 0.88; FON r = 0.7; P < 0.0001) and cyclobutrifluram and pydiflumetofen (SCIT r = 0.83; FON r = 0.67 and 0.77; P < 0.0001) indicate a potential for cross-resistance between these SDHIs for these fungal pathogens. Overall, results suggest that cyclobutrifluram may be used for managing RKN, whereas it should be used judiciously for Fusarium wilt of watermelon and gummy stem blight due to the existence of insensitive isolates to the fungicide.

Interaction of Meloidogyne incognita (Kofoid &amp; White, 1919) Chitwood, 1949 Race 3 with Meloidogyne javanica (Treub, 1885) Chitwood, 1949 Race 3 in Tomato and Pepper

More than one species of root-knot nematodes can attack field vegetables and they can interact with each other. In this study, the interaction of Meloidogyne incognita race 3 and M. javanica race 3 on susceptible host plants (Falkon and Sena) were investigated in a growth chamber under controlled conditions. Experiments were arranged as a randomized plots design with four replications. The incidence of two Meloidogyne species in tomato and pepper hosts were determined by esterase phenotypes. No interaction was observed between the species after the mixed inoculation of 1000 J2 M. incognita race 3 and 1000 J2 M. javanica race 3 on the susceptible tomato plant (P≤0.05). Among mixed inoculation of the two species in the susceptible pepper, only the incidence of M. incognita race 3 was increased, while M. javanica race 3 was not detected in host plants.

Nematode-suppressive and plant growth-enhancing effects of Citrus spp. derivatives against Meloidogyne incognita on tomato

Plant-based derivatives (powders, pellets or extracts) are amongst the most effective types of organic soil amendments for the management of root-knot nematodes (Meloidogyne spp.). The objective of this study was to examine the effect of derivatives (juice, powder and oil) of fruits of several Citrus species (sweet orange, lemon, lime, mandarin and grapefruit) on the reproduction of Meloidogyne incognita race 2 on susceptible tomato plants, and on the vegetative growth of the crop under glasshouse conditions. Results show that juices of sweet orange, and possibly also lemon, applied as soil amendments either before planting or after planting, can significantly suppress the build-up of damaging root population densities of M. incognita on infected tomato plants, limit root galling and improve plant growth. Data confirm the nematode-suppressive and plant-growth enhancing effects reported for Citrus fruit-based plant derivatives, applied either as a compost, powder, extract or pellet.

Suppression of Meloidogyne incognita race 2 with some entomopathogenic agents

Suppression of Meloidogyne incognita race 2 with some entomopathogenic agents

Effect of Soil Temperature on Reproduction of Root-knot Nematodes in Flue-cured Tobacco with Homozygous Rk1 and/or Rk2 Resistance Genes.

Most commercial flue-cured tobacco cultivars contain the Rk1 resistance gene, which provides resistance to races 1 and 3 of Meloidogyne incognita and race 1 of M. arenaria. A number of cultivars now possess a second root-knot resistance gene, Rk2. High soil temperatures have been associated with a breakdown of root-knot resistance genes in a number of crops. Three greenhouse trials were performed from 2014 to 2015 investigate the effect of high soil temperature on the efficacy of Rk1 and/or Rk2 genes in reducing parasitism by a population of M. incognita race 3. Trials were arranged in randomized complete block design in open-top growth chambers set at 25°, 30°, and 35°C. Plants were inoculated with 3,000 eggs and data were collected 35 days post-inoculation. Galling, numbers of egg masses and eggs, and reproductive index were compared across cultivar entries. Nematode reproduction was reduced at 25°C and 30°C on entries possessing Rk1 and Rk1Rk2 compared to the susceptible entry and the entry possessing only Rk2. However, there were often no significant differences in reproduction at 35°C between entries with Rk1 and/or Rk2 compared to the susceptible control, indicating an increase of root-knot nematode parasitism on resistant entries at higher temperatures. Although seasonal differences in nematode reproduction were observed among experiments, relative differences among tobacco genotypes remained generally consistent.

Crudely-milled soil amendments of South African medicinal plants suppress population densities of Meloidogyne incognita race 2 and enhance vegetative growth and yield of tomato under microplot and field conditions

Crudely-milled soil amendments of South African medicinal plants suppress population densities of Meloidogyne incognita race 2 and enhance vegetative growth and yield of tomato under microplot and field conditions

Temperature Effects on Development of Meloidogyne Enterolobii and M. Floridensis.

Meloidogyne enterolobii and M. floridensis are virulent species that can overcome root-knot nematode resistance in economically important crops. Our objectives were to determine the effects of temperature on the infectivity of second-stage juveniles (J2) of these two species and determine differences in duration and thermal-time requirements (degree-days [DD]) to complete their developmental cycle. Florida isolates of M. enterolobii and M. floridensis were compared to M. incognita race 3. Tomato cv. BHN 589 seedlings following inoculation were placed in growth chambers set at constant temperatures of 25°C, and 30°C, and alternating temperatures of 30°C to 25°C (day–night). Root infection by the three nematode species was higher at 30°C than at 25°C, and intermediate at 30°C to 25°C, with 33%, 15%, and 24% infection rates, respectively. There was no difference, however, in the percentages of J2 that infected roots among species at each temperature. Developmental time from infective J2 to reproductive stage for the three species was shorter at 30°C than at 25°C, and 30°C to 25°C. The shortest time and DD to egg production for the three species were 13 days after inoculation (DAI) and 285.7 DD, respectively. During the experimental timeframe of 29 d, a single generation was completed at 30°C for all three species, whereas only M. floridensis completed a generation at 30°C to 25°C. The number of days and accumulated DD for completing the life cycle (from J2 to J2) were 23 d and 506.9 DD for M. enterolobii, and 25 d and 552.3 DD for M. floridensis and M. incognita, respectively. Exposure to lower (25°C) and intermediate temperatures (30°C to 25°C) decreased root penetration and slowed the developmental cycle of M. enterolobii and M. floridensis compared with 30°C.

Bacillus-Based Products to Control Meloidogyne incognita Races 3 and 4 in Cotton and Compared Histopathology Using B. methylotrophicus

Cotton meloidoginosis caused by Meloidogyne incognita races 3 and 4 is an important disease and can cause intense damage. The objective of this work was to test the effectiveness of commercial Bacillus-based products in the control of M. incognita races 3 and 4 of cotton in a greenhouse. Plants with and without nematode inoculation were used and subsequently evaluated for 200 days after the application of treatments. The products with Bacillus subtilis, B. amyloliquefasciens and B. subtilis + B. lincheniformis showed the best results in terms of shoot fresh matter weight. In relation to shoot dry weight, treatments with B. methylotrophicus (87 g, with nematode) and B. subtilis (80 g, with nematode) were superior, with emphasis on B. methylotrophicus. In the evaluation of root fresh weight, only the treatment with B. methylotrophicus (148.8 g, with nematode) provided statistically higher weight than the control. In item dry weight of root without nematode and nematode reproduction factor, the treatment with B. methylotrophicus stood out from the other treatments, making this the selected product to conduct the subsequent tests. With the acid fuchsin staining method, it was possible to verify that there was reduction in the penetration of J2 in the first days for plants treated with the bacteria. Upon adoption of the toluidine blue staining method, it was possible to observe abnormalities in giant cells with formation of vacuoles, thinner cell wall and females with large vacuoles inside. Thus, there is evidence that the use of biological products can be effective in controlling M. incognita.

Bell pepper rootstocks with multiple resistance to soilborne diseases

Grafting has been increasingly used to overcome soilborne pathogens. The commercial rootstock hybrids AF-8253 (Sakata) and Fortaleza (Takii), as well as Embrapa’s new hybrid, BRS Acará, were evaluated as rootstocks for the bell pepper hybrids Margarita (Syngenta) and Pampa (Clause) as scions, under natural infestation of Ralstonia pseudosolanacearum, as well as upon artificial inoculation with a) ten Ralstonia isolates, b) one Phytophthora capsici isolate, c) Meloidogyne incognita race 1, and d) Meloidogyne enterolobii (only rootstocks for c and d). Grafted bell peppers consistently showcased a higher productivity than did non-grafted ones under natural R. pseudosolanacearum infestation, and the rootstock genotype affected fruit size distribution. Rootstocks presented higher resistance than did commercial bell pepper hybrids (scions) for 6 out of 10 Ralstonia isolates. AF-8253 and BRS Acará displayed an immune-like response to P. capsici, while Fortaleza was moderately resistant (25% symptomatic plants) and the bell pepper hybrids (scions) were susceptible (100% symptomatic plants). Rootstocks were immune to M. incognita race 1, but slightly (AF-8253 and BRS Acará) or moderately (Fortaleza) resistant to M. enterolobii. Grafting with BRS Acará, as well as with AF-8253 or Fortaleza, is recommended for managing bacterial wilt, Phytophthora blight, and root-knot nematodes.

Determination of the efficacy of two local Beauveria bassiana (Bals.-Criv.) Vuill, 1912 (Hypocreales: Cordycipitaceae) isolates (Bb-1 and Bv-1) against root-knot nematodes

Root-knot nematodes cause economic damage to various agricultural products, especially vegetables globally. Due to the adverse effects of pesticides on the environment and human health, entomopathogenic fungi are one of the biological control agents used in pest control. In this study, the effects of two different local isolates of Beauveria bassiana (Bals.-Criv.) Vuill, 1912 (Hypocreales: Cordycipitaceae) (Bb-1 and Bv-1) at 106, 107, and 108 CFU ml-1 concentrations were investigated against Meloidogyne incognita race 1 (Kofoid and White, 1919) and Meloidogyne javanica (Treub, 1885) (Tylenchida: Meloidogynidae) on tomato plants. Sixty days after the nematode inoculation, the number of egg packs formed in each plant, plant height (cm), wet plant weight (g), dry plant weight (g), and wet root weight (g), and root dry weight (g) were determined. According to the results, Beauveria bassiana Bb-1 and Bv-1 isolates significantly reduced the reproductive ability of root-knot nematodes. In both isolates, 108 CFU ml-1 concentrations were more effective against M. javanica and M. incognita race1 than other concentrations. Bb-1 isolate is more effective than Bv-1 isolate against M. javanica. On the other hand, the Bv-1 isolate is more effective than another isolate against M. incognita race 1. Entomopathogenic fungi (Bb-1 and Bv-1) are a promising long-term biocontrol strategy in agriculture against root-knot nematodes.

Identification of Four Populations of Meloidogyne incognita in Georgia, United States, Capable of Parasitizing Tomato-Bearing Mi-1.2 Gene

Meloidogyne incognita, the southern root-knot nematode (RKN), is the most predominant plant-parasitic nematode species of tomato and causes significant yield loss. The Mi-1.2 gene confers resistance in tomatoes to M. incognita; however, virulent RKN populations capable of parasitizing resistant tomato cultivars have been reported from different regions in the world. Four naturally occurring virulent populations of M. incognita were found in vegetable fields from four counties in Georgia with no history of tomato cultivation of the Mi gene. Two consecutive greenhouse trials showed that all four virulent RKN populations reproduced on tomato cultivars, including Amelia, Skyway, and Myrtle, with the Mi-1 gene, while an avirulent population of M. incognita race 3 was unable to overcome host resistance. Virulent RKN populations varied in reproduction among resistant cultivars, with Ma6 population having the greatest reproduction potential. No difference in penetration potential of the virulent (Ma6) and avirulent populations was found on susceptible and resistant tomato cultivars. However, virulent Ma6 population females were successful at egg-laying, whereas avirulent female development was arrested in the resistant cultivars. The virulent Ma6 population also induced feeding sites in the roots of resistant cultivars, whereas the avirulent population did not. To our knowledge, this is the first report of resistance-breaking populations of M. incognita in Georgia and the second state in the United States after California.

Identificação de genótipos de algodoeiro resistentes a Meloidogyne incognita raça 3 usando Blup

ABSTRACT Few genetic resistance sources to root-knot nematodes are known for cotton, and there are no cultivars combining both resistance and good agronomic attributes in Brazil. Techniques that allow an efficient selection of promising sources of genetic resistance are needed. This study aimed to identify cotton genotypes resistant to Meloidogyne incognita race 3 via REML/Blup. The experiment was completely randomized, with 32 genotypes and seven replicates, in a protected environment. The statistical model 83 was used. The root weight, final population, reproduction factor and reproduction index were estimated. The final population and reproduction index presented the highest values for genotypic variance and genetic variation coefficients, indicating a favorable situation for the selection of cotton genotypes resistant to the nematode. The mean heritability (h2mg) of the genotype was higher than 85 % for the final population, reproduction factor and reproduction index, opening a possibility of selection success based on genotype means. The genotypes CS8601, SA2572, Coodetec 404 and BJ 3128 are promising for crosses aiming the selection of genotypes resistant to the nematode.

REACTION OF PASSION FRUIT GENOTYPES TO THE COMPLEX Meloidogyne incognita AND Fusarium solani

ABSTRACT The interaction between Meloidogyne and Fusarium can alter the resistance behavior of passion fruit genotypes. The study was aimed to evaluate the reaction of genotypes of Passiflora spp. to Meloidogyne incognita race 3 (Mi)-Fusarium solani (Fs) complex. The assay was carried using RBD in the factorial arrangement: 10 genotypes (BRS-SC, M-19-UFV, P. alata, P. nitida, P. giberti, P.setacea, P. mucronata, P. murifolia, P. cincinnata, P. ligularis) x 3 treatments (Mi, Mi+Fs, Fs). After 180 days of planting the reaction to Mi was determined by RF (Pi/Pf) and to Fs by lesions size in roots and stems. According to the criteria of Oostenbrink and Moura and Regis, BRS-SC, M-19-UFV. P. alata and P. cincinnata behaved as resistant and P. giberti as susceptible. According to the Taylor and Sasser, BRS-SC, M-19-UFV, P. alata, P. cincinnata and P. giberti behaved as resistant, moderately resistant, moderately suscetible and susceptible, respectively. Lower percentage of plants with symtoms of Fs was found in P. mucronata, P. nitida, P. setacea, P. cincinnata and M-19-UFV In the presence of both pathogens, M-19-UFV, P. alata and P. nitida were those with larger lesion. In the presence de Fs, BRS-SC, P. alata, P. cincinnata and P. ligularis showed the largest lesions.

QUANTIFICATION OF DAMAGE AND YIELD LOSSES AND MANAGEMENT OF ROOT-KNOT NEMATODES IN CONILON COFFEE

ABSTRACT Commercial exploitation of the coffee crop is one of the most important activities in the world’s agricultural sector. One of the main phytosanitary problems affecting the crop is the presence of Meloidogyne incognita. Several measures have been tested for the management of this pathogen, albeit with low efficiency. The objective of this work was to quantify the damage and losses and to manage M. incognita race 1 with Pochonia chlamydosporia and Trichoderma harzianum biological nematicides, comparing them to a chemical nematicide. The experiment was carried out in a commercial area naturally infested by the nematode and cultivated with the conilon coffee variety ‘Vitória INCAPER 8142’, clone V02. The treatments were tested with Carbofuran nematicide and with biological nematicides composed of P. chlamydosporia Pc-10 and T. harzianum ESALQ 1306. The biological products were applied alone or in combination. The lowest NPF (final nematode population) occurred in plants treated with P. chlamydosporia and Carbofuran. P. chlamydosporia was the most effective biological agent in the management of M. incognita. There was a reduction in production with an increase in the nematode population. The highest application costs of management methods for M. incognita race 1 per hectare were for three and two applications of Carbofuran and three applications of P. chlamydosporia + T. harzianum. The treatments with lowest application costs were one application of T. harzianum and one application of P. chlamydosporia. It was concluded that all treatments were efficient for the management of M. incognita race 1, causing a decrease in the roots and soil population.

Isolation and characterization of endophytic bacteria from tomato foliage and their in vitro efficacy against root-knot nematodes.

Fifteen endophytic bacteria were isolated from leaves and stems of Solanum lycopersicum and Solanum pimpinellifolium collected from different locations of the Jorhat district of Assam and characterized by morphological, cultural, biochemical and molecular approaches. An in vitro study was carried out to evaluate their potentiality as biological control agents against second stage juvenile of the root-knot nematode, Meloidogyne incognita race2. Thirty second stage juveniles (J2) of M. incognita race 2 were exposed to cell free culture filtrates of all the 15 bacterial endophytes in a sterile cavity block at a concentration of S(100%), S/2(50%), S/4(25%), S/6(17%) and S/10(10%) for a duration of 6, 12, 24, and 48 hr. The results revealed that all the isolates had the potentiality to significantly increase the mortality of the second stage juveniles (J2). The percent mortality was directly proportional to the duration of exposure time and the concentration of the culture filtrate. The isolate BETL2 showed the best result with 81.47% mortality of juveniles followed by isolates BETL4 (81.43%), BETLI (79.07%), BETS2 (78.87%), and BETL6 (78.17%). The 16S rRNA sequence amplification results indicated that these isolates were Bacillus marisflavi (BETL2), Bacillus altitudinis (BETL4), Microbacterium arborescens (BETL1), Exiguobacterium indicum (BETS2), and Bacillus marisflavi (BETL6). The four most efficient isolates were structurally analyzed using a scanning electron microscope and this revealed that the length and breadth of isolates—BETLI, BETL2, BETL4, and BETS2 were 701.70 nm × 348.30 nm, 954.10 nm × 303.10 nm, 984.10 nm × 332.90 nm and 1422.00 nm × 742.00 nm, respectively. The result of the present study indicated that the above four novel strains of endophytic bacterial isolates enhance the mortality of J2 of M. incognita race2 and has the potentiality as biological control agents against M. incognita.