Nematode Reproduction Research Articles

Evaluation of the Reproductive Toxicity of Fluopimomide in Meloidogyne incognita and Caenorhabditis elegans

Fluopimomide is a new pesticide that is widely applied in agriculture; however, the effects and molecular mechanisms of fluopimomide in inhibiting nematode reproduction remain unknown. In this study, the effects of fluopimomide on the development and infection of Meloidogyne incognita and the reproductive toxicity in Caenorhabditis elegans were evaluated. Results showed that, in comparison to inoculated control, fluopimomide at 0.33, 0.67, and 1.0 mg/kg soil significantly (p < 0.05) delayed M. incognita development and decreased the reproduction in pot experiments. Fluopimomide notably reduced the galls index with a control effect of 78.6%, 67.9%, and 50.0%, respectively. In addition, a dose–response relationship existed between the brood size and germ cell number of C. elegans and fluopimomide concentrations. Compared with the control group, fluopimomide at 1.0 and 5.0 mg/L notably (p < 0.001) increased the number of cell corpses per gonad in the N2 strain of C. elegans by 8.8- and 14.4-fold, respectively. The number of cell corpses per gonad was similar between the fluopimomide treated worms and the control group in mutants of ced-3, ced-4, and ced-9. Further evidence revealed fluopimomide significantly enhanced the expression of cep-1, egl-1, and clk-2, while no obvious effects were observed in their mutants. Taken together, these results indicated that fluopimomide inflicted DNA damage and induced the core apoptosis pathway caused by germ-cell apoptosis, leading to the reduction of the brood size of C. elegans.

Virulence and Reproduction of Entomopathogenic Nematodes Isolated from a Single Mexican Locality

Abstract Entomopathogenic nematodes (EPNs) are important biological control agents of insect pests. Strains or isolates obtained in specific regions and utilized in situ might contribute to the success of EPNs, since they are adapted to local abiotic conditions. We isolated and identified three isolates each of Heterorhabditis bacteriophora Poinar and Steinernema carpocapsae (Weiser) from soils at Saltillo, Coahuila State, Mexico. These six isolates were bioassayed against larvae of Tenebrio molitor L., using six concentrations of infective juveniles (IJs) per larva (0, 10, 25, 50, 100, 200). EPN-induced mortality of the isolates ranged from 15.2% to 100%. The designated M5 isolate of S. carpocapsae caused 100% mortality after 72 h at concentrations ≥25 IJs/larva with a median lethal concentration of 4.99 IJs/larva. Comparison of mortality levels induced at the same concentration of the six EPN isolates indicated that the Steinernema isolates, in general, induced higher mortality levels than the Heterorhabditis isolates. IJ production in T. molitor larvae also was greatest with the M5 isolate of S. carpocapsae following exposure of larvae to a concentration of 100 IJs/larva with a mean of 17,320 IJs/larva. Based on induced mortality and IJ production, the S. carpocapsae M5 isolate appears to be a viable candidate for further study and possible development for use in insect pest management programs. This study indicates that naturally coexisting local nematode isolates possess different attributes critical for their use as biocontrol agents.

Study on two nematode species suggests climate change will inflict greater crop damage

Food security has become one of the greatest challenges of the millennium and it is predicted to be exacerbated by climate change due to the adverse effects of soil temperature on crop productivity. Although plant-parasitic nematodes are one of the most important limiting factors of agricultural production, the fate of soil temperature in their biology is not fully understood. Here we present the effects of soil temperature on survival, reproduction, virulence, and disease severity from the perspective of two nematode species Rotylenchulus reniformis and Meloidogyne floridensis. The two nematode species were purposefully selected to represent a significant threat to annual and perennial crops. We employed novel approaches of direct as well as indirect heat exposure to evaluate nematode biology. The direct heat exposure assay involved the exposure of nematodes to hot water in a heating block at 32, 33, and 34 °C for 7 h, and subsequent evaluation of their survival after 18 h. The indirect exposure assay employed a commercial heat mat to raise soil temperatures to 32, 33, and 34 °C for 7 h during the daytime, and subsequent evaluation of nematode reproduction, virulence, and/or disease severity over the period of 6 weeks after inoculation. When directly exposed to hot water at 34 °C, the survival of R. reniformis increased by 10% while the survival of M. floridensis decreased by 12% relative to that at 32 °C. Upon increasing soil temperatures from 32 to 34 °C, the reproduction of R. reniformis and M. floridensis decreased by 49% and 53%, respectively. A significant reduction in the reproduction of M. floridensis occurred when soil temperature was increased from 33 to 34 °C, however, the same condition did not significantly affect R. reniformis reproduction suggesting the latter species has a greater ability to adapt to increasing soil temperature. Additionally, the virulence of R. reniformis was greater at 33 and 34 °C relative to that at 30 °C indicating increased aggressiveness of the nematode at higher soil temperatures. The virulence of M. floridensis appeared to be decreased as evident from increased root biomass when soil temperature was increased from 32 to 34 °C, however, the greater root biomass may have resulted from increased root galling at the higher temperatures. Results of the current study suggest that while higher soil temperatures due to climate change may lead to reduced nematode reproduction, crop losses will likely increase due to increased nematode virulence. Through the current study, we report practical evidence of the quantitative impact of climate change on the biology of plant-parasitic nematodes. Further studies involving a wider range of temperature and exposure time are needed to better understand nematode biology under climate change.

Effective combination of arugula vermicompost, chitin and inhibitory bacteria for suppression of the root-knot nematode Meloidogyne javanica and explanation of their beneficial properties based on microbial analysis.

Root-knot nematodes (Meloidogyne spp.) are dangerous parasites of many crops worldwide. The threat of chemical nematicides has led to increasing interest in studying the inhibitory effects of organic amendments and bacteria on plant-parasitic nematodes, but their combination has been less studied. One laboratory and four glasshouse experiments were conducted to study the effect on M. javanica of animal manure, common vermicompost, shrimp shells, chitosan, compost and vermicompost from castor bean, chinaberry and arugula, and the combination of arugula vermicompost with some bacteria, isolated from vermicompost or earthworms. The extract of arugula compost and vermicompost, common vermicompost and composts from castor bean and chinaberry reduced nematode egg hatch by 12-32% and caused 13-40% mortality of second-stage juveniles in vitro. Soil amendments with the combination vermicompost of arugula + Pseudomonas. resinovorans + Sphingobacterium daejeonense + chitosan significantly increased the yield of infected tomato plants and reduced nematode reproduction factor by 63.1-76.6%. Comparison of chemical properties showed that arugula vermicompost had lower pH, EC, and C/N ratio than arugula compost. Metagenomics analysis showed that Bacillus, Geodermatophilus, Thermomonas, Lewinella, Pseudolabrys and Erythrobacter were the major bacterial genera in the vermicompost of arugula. Metagenomics analysis confirmed the presence of chitinolytic, detoxifying and PGPR bacteria in the vermicompost of arugula. The combination of arugula vermicompost + chitosan + P. resinovorans + S. daejeonense could be an environmentally friendly approach to control M. javanica.

Management of Root-Knot Nematode on Okra through Bio-Agents

A pot study was conducted to assess the efficacy of various fungal and bacterial antagonists as seed coating treatments against Meloidogyne javanica, a root-knot nematode that infects okra plants. The seeds of okra cv. Pusa Sawani were subjected to treatments with Trichoderma viride, Purpureocillium lilacinum, and Pseudomonas fluorescens at a rate of 2 g/kg seed. As a comparison, Carbosulfan 3G was used as a control, applied at a rate of 3g/kg soil. The treated seeds were then planted in soil infested with two second-stage juveniles of the root -knot nematode per gram of soil. After 45 days of sowing, it was observed that the okra plants exhibited enhanced growth, while the population of root-knot nematodes was significantly reduced in all treatment groups compared to the untreated control. Among the different bio agents tested, Purpureocillium lilacinum exhibited the best treatment followed by Trichoderma viride and Pseudomonas fluorescens for increase plant growth characters as well as reduced nematode reproduction.

Efficacy of Aspergillus tubingensis GX3' Fermentation against Meloidogyne enterolobii in Tomato (Solanum lycopersicum L.).

Meloidogyne enterolobii is one of the most virulent root-knot nematodes (RKNs). Aspergillus tubingensis Raoul Mosseray, 1934, is used to produce bioactive substances, enzymes, and secondary metabolites. However, no research has been conducted yet on the efficacy of A. tubingensis against plant-parasitic nematodes. Thus, the novel research was planned to evaluate the biocontrol efficacy of A. tubingensis fermentation against M. enterolobii. The findings showed that egg hatching inhibition and mortality of M. enterolobii increased with increasing concentration of fermentation and exposure time. The maximum second-stage juveniles (J2s) mortality was achieved via 100% fermentation at 72 h. Similarly, 100% fermentation inhibited 99.9% of egg hatching at 8 d. A. tubingensis fermentation increased plant biomass, decreased second-stage juvenile invasion, and inhibited nematode development and reproduction in greenhouse conditions. A. tubingensis reduced J2 invasion into tomato roots by 42.84% with CS+ (coated seeds plants with nematodes inoculum) and 27.04% with T+ (100% fermentation broth and nematodes inoculum both) treatments. Moreover, CS+ and T+ treatments decreased nematode development by 54.31% and 21.48%, respectively. It is concluded that the A. tubingensis GX3 strain can be used as a novel microbial biocontrol agent against M. enterolobii.

Divergent Responses of Tomato Cultivars with Resistance to Tomato Yellow Leaf Curl Virus as Infected by Meloidogyne javanica

Commercial tomatoes are usually complex F1 hybrids with multiple resistances genes from different wild Solanum species. The response of tomato cultivars with resistance to root-knot nematodes (RKN) and Tomato yellow leaf curl virus (TYLCV) as infected by Meloidogyne javanica was determined in a controlled environment and field conditions. Four treatments were tested, viz. tomato cultivars with (i) RKN resistance alone; (ii) combination of RKN and TYLCV resistance (RKN + TYLCV); (iii) TYLCV resistance alone; and (iv) control (susceptible to the nematode and virus). The RKN-resistant plants effectively suppressed nematode infection and reproduction both in a controlled environment and in field conditions. The RKN + TYLC-resistant plants were less effective (p < 0.001) than the RKN plants in a controlled environment, and their resistance levels were significantly reduced in the field. Nonetheless, the RKN + TYLCV plants supported lower (p < 0.001) nematode infection and reproduction than the susceptible control plants. The TYLCV-resistant plants reduced (p < 0.001) nematode infection and reproduction compared to the susceptible control in a controlled environment and in field conditions. The divergent response of tomato cultivars with resistance to TYLCV via infection by M. javanica can be attributed to the genetic background of the cultivars.

Microbiome transplant can effectively manage root-knot nematode infectivity in tomato

A critical factor in alleviating nematode menace in horticultural crops is discerning the nature of microbial communities associated with roots and rhizosphere. Root-knot nematodes (Meloidogyne spp.) are one of the major constraints for obtaining high yields of vegetable crops. Root-knot nematode-infected and uninfected plants occur in agricultural fields. Most biocontrol strategies used for nematode management focus on introducing a single bioagent. Recently, microbiome transplant has been found effective in curing human diseases and is also used to cure animals. Here we evaluated the role played by the microbial communities in managing M. incognita infection on tomatoes grown in protected cultivation by transplanting the microbial slurry extracted from the rhizosphere soil of the healthy plants and those infected with the root-knot nematode. The relative abundance of Gram-negative bacteria (11.11 % and 16.08 %) and anaerobes (39.58 % and 16.59 %) phospholipid fatty acids (PLFA) was significantly higher in healthy roots and rhizosphere soil. In contrast, Gram-positive bacteria (21.52 % and 37.61 %) were comparatively higher in nematode-infected roots and rhizosphere soil. Nematode penetration and reproduction indices were significantly reduced (34–43 %) by inoculating the healthy plant's unfiltered microbial slurry. However, inoculation with unfiltered microbial slurry from the rhizosphere soil of infected plants increased (8–26 %) nematode penetration and reproduction. Plant growth and fruit yield (13.1 %) of tomatoes were positively influenced by unfiltered microbial slurry from the rhizosphere soil of healthy plants. The significant role of the healthy microbiome transplant in reducing nematode invasion and reproduction and increasing the crop yield of tomatoes grown in protected cultivation suggests that microbial transplants could be an approach to managing plant nematodes.

Reproduction factor of Meloidogyne javanica, M. incognita and Pratylenchus brachyurus in sorghum, millet and sunflower varieties

The use of agricultural species resistant to root-knotting and root-wounding nematodes, in crop rotation systems, keeps the nematode population at low levels, reducing losses and enabling the planting of more susceptible species. In this study, the resistance of sorghum, millet and sunflower genotypes to root-knot nematodes Meloidogyne javanica, M. incognita and Pratylenchus brachyurus was evaluated. The tests were conducted in a greenhouse and the genotypes sown in plastic pots containing 2 L of sterilized substrate and inoculated with 1,600 nematode eggs and juveniles per pot, arranged in a completely randomized design with nine replications. The evaluation of nematode reproduction was performed by counting the number of juveniles/adults per root system and soil, calculating the Reproduction Factor (FR = Pf/Pi). According to the results, all sorghum, millet and sunflower genotypes behaved as resistant to the reproduction of M. javanica, M. incognita and P. brachyurus. Commercial resistant genotypes are indicated for use in rotation of areas infested by these nematodes.

Study on the characterization of pesticide modes of action similarity and the multi-endpoint combined toxicity of pesticide mixtures to Caenorhabditis elegans

With the widespread use of pesticides, the coexistence of multiple low-residue pesticides in environmental media has increased significantly, and the “cocktail” effect caused by this phenomenon has garnered increasing attention. However, owing to the scarcity of information regarding the modes of action (MOAs) of chemicals, the application of concentration addition (CA) models for evaluating and predicting the toxicity of mixture with similar MOAs is limited. Additionally, the joint toxicity laws of complex mixture systems to different toxicity endpoints in organisms remain unclear, and effective methods to test the mixture toxicity on lifespan and reproductive inhibition are lacking. Therefore, in this study, the similarity of pesticide MOAs was characterized using molecular electronegativity-distance vector (MEDV-13) descriptors based on eight pesticides (aldicarb, methomyl, imidacloprid, thiamethoxam, dichlorvos, dimethoate, methamidophos and triazophos). Additionally, the methods of lifespan and reproduction inhibition microplate toxicity analysis of elegans (EL-MTA and ER-MTA) were established to test the lifespan and reproduction inhibition toxicity of Caenorhabditis elegans. Finally, a unified scale synergistic-antagonistic heatmap (SAHscale) method was proposed to explore the combined toxicity of the mixtures on the lifespan, reproduction, and mortality of nematodes. The results showed that the MEDV-13 descriptors could effectively characterize the similarity in MOAs. The lifespan and reproductive ability of Caenorhabditis elegans were significantly inhibited when the pesticide exposure concentration was one order of magnitude lower than the lethal dose. The sensitivity of lifespan and reproductive endpoints to mixtures was dependent on the concentration ratio. The same rays in the mixture had consistent toxicity interactions on the lifespan and reproductive endpoints of Caenorhabditis elegans. In conclusion, we demonstrated the feasibility of MEDV-13 in characterizing the similarity of MOAs, and provided a theoretical basis for exploring the mechanism of chemical mixtures by studying their apparent toxicity of mixtures on nematode lifespan and reproduction endpoints.

The Potency of Abamectin Formulations against the Pine Wood Nematode, Bursaphelenchus xylophilus

Abamectin offers great protection against <i>Bursaphelenchus xylophilus</i>, a well-known devastating pathogen of pine tree stands. Trunk injection of nematicides is currently the most preferred method of control. This study aimed to evaluate the potency of the commonly used formulations of abamectin against <i>B. xylophilus</i>. Twenty-one formulations of abamectin were evaluated by comparing their sublethal toxicities and reproduction inhibition potentials against <i>B. xylophilus</i>. Nematodes were treated with diluted formulation concentrations in multi-well culture plates. And, populations pre-exposed to pre-determined concentrations of the formulations were inoculated onto <i>Botrytis cinerea</i> culture, and in pine twig cuttings. Potency was contrastingly different among formulations, with LC<sub>95</sub> of 0.00285 and 0.39462 mg/ml for the most, and the least potent formulation, respectively. Paralysis generally occurred at an application dose of 0.06 μg/ml or higher, and formulations with high sublethal toxicities caused significant paralysis levels at the tested doses, albeit the variations. Nematode reproduction was evident at lower doses of 0.00053-0.0006 μg/ml both on <i>Botrytis cinerea</i> and pine twigs, with significant variations among formulations. Thus, the study highlighted the inconsistencies in the potency of similar product formulations with the same active ingredient concentration against the target organism, and the need to analyze the potential antagonistic effects of the additives used in formulations.

The influence of biotic and abiotic factors on the development and reproduction of the beet nematode (review)

Purpose. To analyze domestic and foreign scientific sources on the influence of biotic and abiotic factors on the development and reproduction of the beet nematode in the soil.
 Results. Long-term research has established that the development and reproduction of the beet nematode are influenced by a complex of biotic factors, among which the most important are the root secretions of plants grown in a field infected with heteroderosis, which can stimulate or inhibit the emergence of parasite larvae from eggs, infestation of sugar beet sowings with weed that are hosts of heterodera, as well as the presence of various species of fungi and bacteria that attack nematode eggs, larvae, and cysts and are considered natural regulators of nematode in agrocenoses. Among the abiotic factors, according to scientists, temperature, humidity, aeration, type and pH of the soil, oxygen content, etc. have significant influence on the viability of various stages of the beet nematode, the duration of development and the number of its generations.
 Conclusions. The results of research on the influence of biotic and abiotic factors on the vital activity of the beet nematode indicate the complexity of the relationship of this parasite with various plant species, other microorganisms that inhabit the agrocenosis, and environmental conditions. The high ecological plasticity of the nematode contributes to its significant spread in temperate climates, and the increase in the density and harmfulness of its population in the soil is ensured by the cultivation of favorable crops in the field, as well as by the combination of optimal conditions of temperature, humidity and other factors during vegetation. Further study of various factors that, first of all, negatively affect the development and reproduction of the beet nematode will prepare the conditions for the development and implementation of new alternative approaches of nematode control in sugar beet sowings.

Assessing the impact of successive soil cultivation on Meloidogyne enterolobii infection and soil bacterial assemblages

AbstractSoil cultivation may change the soil microbiome and alter interactions between plants and parasites. This work aimed to evaluate temporal changes in plant health, soil microbiome abundance and incidence of the emergent plant‐parasitic nematode, Meloidogyne enterolobii, in two soil fields with different agricultural uses. Soil samples were collected from a commercial tomato production field (agricultural soil) and a single‐cultivation strawberry field (native soil) for two successive years. Tomato plants cv. Early Girl were grown in a greenhouse, and three groups of inoculums were used: Fusarium only, M. enterolobii only and Fusarium + M. enterolobii. After 45 days, plants were evaluated for growth parameters and nematode reproduction and soil bacterial assemblages were assessed using cultivation‐independent sequencing methods (V3/V4 region of the 16S rRNA). Among both soil types, the average root fresh weight increased (56%), along with shoot fresh weight (82%) and fruit fresh weight (76%) in the second year. Moreover, there was an 80.5% decrease in eggs present per root system from the first year to the second. The relative abundance of bacterial assemblages from Year 1 to Year 2 changed for most of the top phyla (e.g., Actinobacteria, Bacteroidetes and Chloroflexi) and genera (e.g., Bacillus, Streptomyces and Flavisolibacter). This study suggests that soil management and year‐to‐year variation can lead to a shift in overall bacterial assemblages, better crop yield and an overall decrease in nematode reproduction.

Biological Control of Plant Parasitic-Nematodes by Plant Growth Promoting-Rhizobacteria

Plant growth promoting-rhizobacteria (PGPR) contributes a significant part in crop health improvement including pest management. It also protects plants from parasitic nematodes damage by exhibiting biocontrol activity besides improving the growth of plants by supplying nutrients, producing phytohormones and inducing modification of plants metabolisms. PGPR decreases or inhibits the hatching of nematode juveniles and suppresses the nematodes development and reproduction by exhibiting various mechanisms such as hyperparasitism, antibiotic synthesis or antibiosis, substrate competition, synthesis of lytic enzymes and induction of resistance in plants. Hence, PGPR could be an efficient biological protective agent that protects agricultural and horticultural crop plants from the infestation of parasitic nematodes.

First Report of the Root-Knot Nematode Meloidogyne enterolobii Parasitizing Eggplant in Mexico.

Eggplant (Solanum melongena L.) is an important vegetable cultivated in Mexico and the state of Sinaloa is the largest producer of eggplants with 90% of the country's total production. In April 2022, eggplants cv. Barcelona exhibiting root-knot, stunted growth, and yellowing were detected in a greenhouse in Culiacán, Sinaloa, Mexico. Disease incidence was approximately 10% (1000 plants evaluated). Ten soil samples were collected from the greenhouse. An average of 400 root-knot nematode second-stage juveniles (J2s) were extracted from 100 g of soil for each sample. Roots were washed with tap water and dissected. Females and egg masses were obtained by dissecting galls. Microscopic examination of the perineal pattern of mature females (n= 10) was round to ovoid, with rounded and high dorsal arch. Females (n= 20) were globular to pear-shaped, body length of 645 to 739 µm, body width of 470 to 559 μm; the stylet was dorsally curved, 15.1 to 16.2 μm long, and with rounded stylet knobs; neck length of 195 to 202 µm and the distance from the base of the stylet to the dorsal gland orifice (DGO) was 4.2 to 5.8 µm. Second-stage juveniles were vermiform, annulated, and tapering at both ends. Morphological characteristics of the females and J2s were consistent with those reported for Meloidogyne enterolobii (Yang and Eisenback 1983). For molecular identification, total DNA was extracted from individual females according to the extraction protocol described by Hu et al. (2011), and the ribosomal intergenic spacer 2 (IGS2) was amplified by PCR using the specific primers Me-F/Me-R for M. enterolobii (Long et al. 2006). PCR amplification generated a 236-bp fragment for the analyzed sample and the amplicon was sequenced. The sequence was deposited in GenBank under the accession number OP004802. BLASTn searches showed 100% identity with available sequences of M. enterolobii from the USA (MH800967) and China (KP411228, MT742011). A phylogenetic tree including published IGS2 sequences for Meloidogyne spp. was constructed based on Maximum Likelihood method. The phylogenetic analysis placed the sequence MeCUB in the same clade with Meloidogyne enterolobii. Pathogenicity tests were performed under greenhouse conditions by inoculating 5000 eggs of a pure population of M. enterolobii on 10 healthy eggplants cv. Barcelona (30-day-old) grown in pots with sterilized soil. Five uninoculated eggplants were used as control. Plants were maintained at 26 to 34°C in a greenhouse for 35 days. Stunted growth and root-galling symptoms appeared on inoculated plants after 21 days, whereas control plants remained symptomless. Nematode reproduction factor (final population density/initial population density) was 0.93 and 2.28 at 28 and 35 days after inoculation, respectively. The nematode on the inoculated roots was morphologically identical to that observed on naturally infected roots in the field. The pathogenicity test was carried out twice with similar results. Meloidogyne enterolobii has been previously reported on eggplants in Puerto Rico (Rammah and Hirschmann 1988). To our knowledge, this is the first report of M. enterolobii causing root-knot of eggplant in Mexico. This nematode is widely distributed in Sinaloa affecting other vegetable crops such as tomato (Martínez-Gallardo et al. 2015), chili (Carrillo-Fasio et al. 2020), and cucumber (Gómez-González et al. 2020), so future studies are required to evaluate integrated management strategies.

Screening of Some Popular Egyptian Varieties of Some Solanaceous Vegetables Against Root-Knot Nematode, Meloidogyne Javanica

Sixteen cultivars varieties of the following solanaceous vegetables; eggplant varieties. (Balady, Classic, Long white and Woman bag), pepper varieties. (Balady, Deer horn, Lamashiar, Mexican, Red sweet zoly, Saudi and Top star) and tomato varieties (Al-Basha 1077, Sama, Strain-B, Super Cristal and Tomato 935) were tested for their host response to Meloidogyne javanica. According to rating scale based on nematode reproduction, Classic, Long white & Woman bag varieties. of eggplant and Top star variety. of pepper were considered as highly susceptible hosts with (Rf) values 18.04, 15.24, 19.82 & 17.30 folds, respectively. While, Balady variety. of eggplant and Strain-B variety. of tomato were classified as moderately susceptible hosts to nematode infection with (Rf) values 5.28 and 5.07 folds. Lamashiar variety. of pepper and tomato varieties. Super Cristal, Al- Basha 1077 &Tomato 935were found less susceptible with (Rf) values ranged between 1.07 and 4.83 folds. On the other hand, M. javanica failed to reproduce and multiple on Deer horn variety. of pepper, which was ranked as highly resistant host with (Rf) value 0.59-fold. Whereas, Balady variety. of pepper and Sama variety. of tomato were ranked as resistant hosts. Nematodes could not reproduce, develop, or penetrate the roots of Mexican, Red sweet zoly and Saudi varieties. of pepper, which were ranked as immune hosts to M. javanica infection.

Chemical composition and antioxidant properties of beetroot parasitized by Meloidogyne javanica and treated with elicitors

Beetroot is rich in nutrients and bioactive compounds, such as, betalains and phenolics. The objective of this work was to analyze the chemical composition and antioxidant properties of beetroot parasitized by Meloidogyne javanica and treated with elicitors. Beet seedlings were inoculated with 1000 eggs and second-stage juveniles of M. javanica and treated with elicitors based on mannan oligosaccharides, citrus biomass, or acibenzolar-S-methyl (ASM). At 60 days after inoculation, plants were evaluated for nematode reproduction factor (RF), proximate composition, betalains, phenolic compounds, and antioxidant activity. Beetroot was found to be susceptible to M. javanica, with RF values ranging from 15.26 to 27.94. ASM and citrus biomass treatments increased ash content by 15–25% in nematode-inoculated plants. There was no treatment effect on moisture or protein content, but uninoculated plants had higher total phenolic content (~35%) than inoculated plants. Nematode infection was found to compromise betalain production but did not impact antioxidant activity. Nematode-inoculated plants showed reduced sucrose content and increased glucose and fructose levels in all treatments. Regardless of the elicitor used, beetroots inoculated M. javanica exhibit deformities that render them unmarketable in fresh form. However, the results indicate that nematode-infected beetroot may be suitable for industrial processing and compound extraction.

Assessment of Biomedical Waste in West, Central, North Zones of Hyderabad

Waste disposal is especially important when it comes to medical supplies, as some waste can be contaminated with diseases and dangerous pathogens. Not all biomedical waste is treated the same way and different disposal companies use different methods such as autoclaving, incineration, chemicals and microwaves. Improper disposal of medical waste causes environmental pollution, unpleasant odours, the growth and reproduction of insects, rodents and nematodes, and injuries from blood-contaminated sharp objects, typhoid fever, cholera, hepatitis, etc. can lead to disease transmission. Thisstudy will reveal the current processes and environmental impacts of biomedical waste management by examining the quantity and quality of biomedical waste (BMW) generated by pharmacies, laboratories and multiple speciality hospitals.

Registration of ‘Giant’ forage cowpea

Abstract‘Giant’ (Reg. no. CV‐348, PI 701902) is a southern root‐knot nematode (Meloidgyne incognita race 3 and race 4)–resistant forage cowpea [Vigna unguiculata (L.) Walp.] developed by Texas A&M AgriLife Research at Overton, TX. Giant is intended for use as a warm‐season cover crop, a forage and hay crop, and supplemental browse for white‐tailed deer. Giant is an indeterminate, forage type cowpea that produces biomass from May through September in northeast Texas but also flowers 25 days earlier than ‘Iron & Clay’ cowpea, allowing seed production in northeast Texas before the first average frost date. Single nucleotide polymorphism analysis confirmed the variety mix Iron & Clay as the parental source population for Giant. Forage production of Giant at Overton, TX, in 2019 and 2020 was 5.3 and 6.0 Mg dry matter (DM) ha−1, respectively. Forage production of Giant in 2019 at Prairie and Starkville, MS, was 2.8 and 2.9 Mg DM ha−1, respectively. Protein content of Giant in 2019 at Prairie and Starkville was 21.1 and 21.2%, respectively. Forage production of Giant in 2019 at Chillicothe, TX and Lockett, TX, was 2.6 and 3.6 Mg DM ha−1, respectively. Top growth nitrogen (N) yield of Giant in 2019 at Chillicothe, TX, and Lockett, TX, was 67 and 65 kg N ha−1, respectively. Based on very low nematode reproduction, Giant is rated resistant and partially resistant to southern root‐knot nematode race 3 and race 4, respectively.

Susceptibility of seven strawberry cultivars to Belonolaimus longicaudatus and interaction with Phytophthora cactorum

Summary Belonolaimus longicaudatus and Phytophthora cactorum are pathogens threatening Florida strawberry production. The interaction among these and cultivar susceptibility were assessed in this study. Cultivars ‘Sensation® Florida127’, ‘Florida Brilliance’, ‘Florida Radiance’, ‘Winterstar™ FL 05-107’, ‘Florida Elyana’, ‘Strawberry Festival’ and ‘Florida Beauty’ were used to conduct one trial using plug transplants and a second trial using bare-root transplants, which was repeated twice. A factorial combination of P. cactorum (+/−) and B. longicaudatus (+/−) inoculation was applied to evaluate strawberry cultivar resistance to P. cactorum and B. longicaudatus as well as their interaction. The effect of P. cactorum on the canopy, root length, and root and shoot weight was dependent on cultivars. For the plug transplant trial, the overall average of plant mortality among all tested strawberry cultivars was 0.1%, suggesting higher tolerance against P. cactorum when vigorous transplants were used. Conversely, the repeated bare-root transplant trial demonstrated different levels of susceptibility in strawberry cultivars when transplants were inoculated with P. cactorum. ‘Sweet Sensation’ ‘Florida127’, ‘Florida Brilliance’, ‘Florida Radiance’ and ‘Winterstar FL 05-107’ were highly susceptible, whereas ‘Florida Elyana’ and ‘Strawberry Festival’ were resistant. Moreover, ‘Florida Beauty’ was moderately resistant to P. cactorum. Our findings demonstrated the importance of using vigorous transplants to reduce P. cactorum damage. Sting nematode reproduction was suppressed when strawberry transplants were inoculated with P. cactorum, suggesting an antagonistic interaction between the pathogens. None of the cultivars was tolerant to B. longicaudatus as this nematode reproduced from 13.4- to 23.8-fold and caused root damage under glasshouse conditions.