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Abstract The utilization of Trichoderma longibrachiatum filtrate as a safe biocontrol method for producing zinc nanoparticles is a promising approach for managing pests and diseases in agricultural crops. The identification of Trichoderma sp. was achieved through PCR amplification and sequencing of 18s as ON203115, while the synthesis of ZnO-NPs was accomplished by employing Trichoderma filtration. The presence of ZnO-NPs was confirmed by observing a color change to dark green, along with the use of visible and UV spectrophotometers, and the formation and chemical structure of ZnO-NPs were examined. Direct exposure to ZnO-NPs exhibited a significant inhibitory effect on the growth of Fusarium oxysporum at 80.73% compared with control. Also, the percent mortality of Meloidogyne incognita second juveniles stage (J2s) results showed 11.82%, 37.63%, 40.86%, and 89.65% after 6, 12, 24, and 72 h, respectively in vitro. Disease resistance was assessed in the greenhouse against M. incognita and F. oxysporum using the drench application of ZnO-NPs. The application of ZnO-NPs significantly reduced the disease severity of F. oxysporum and improved the quality and quantity of sweet pepper yield. In addition, the application of ZnO-NPs to M. incognita resulted in a significant reduction in the number of nematode galls, egg masses per root, eggs/egg mass, and females by 98%, 99%, 99.9%, and 95.5% respectively. Furthermore, it was observed that the application of ZnO-NPs to pepper plants not only inhibited the growth of F. oxysporum and M. incognita, but also promoted the recovery of pepper plants as indicated by improvements in stem length by 106%, root length 102%, fresh weight 112%, root fresh weight 107%, and leaf area 118% compared to healthy control plants. Additionally, real-time PCR application and DD-PCR technique revealed that the application of ZnO-NPs stimulated the secretion of certain enzymes. These findings suggest that the biosynthesized ZnO-NPs possess anti-nematode and antifungal properties, making them effective for protecting plants against M. incognita and F. oxysporum invasion in soil. This study significantly contributes to our understanding of the nematicidal and fungicidal activities of ZnO-NPs in suppressing soil-borne diseases.

Five new and four known species of the genus Dorylaimellus Cobb, 1913 are described and illustrated from the Western Ghats of India. Dorylaimellus attenuatus sp. nov. has a 0.73–0.84 mm long body; lip region rounded, offset; odontostyle attenuated with indistinct lumen, odontophore 9–10 µm long; expanded part of pharynx 39–48% of neck length; female genital system amphidelphic and tail long filiform. Dorylaimellus cylindricaudatus sp. nov. has a 1.0–1.15 mm long body; lip region rounded, offset; odontostyle 4 µm long, odontophore 11–12 µm long; expanded part of pharynx 47–56% of neck length; female genital system amphidelphic, and tail elongate-cylindrical with rounded terminus. Dorylaimellus karnatakensis sp. nov. has a 1.2–1.3 mm long body; lip region rounded, offset; odontostyle 5 µm long, odontophore 12–13 µm long; expanded part of pharynx 45–53% of neck length; female genital system amphidelphic; spicules 22 µm long, ventromedian supplements four, and tail elongate-conoid dorsally convex. Dorylaimellus kasplateauensis sp. nov. has a 0.68–0.83 mm long body, lip region with a weak perioral disc; odontostyle 6–7 µm long, odontophore 11–14 µm long; expanded part of pharynx 38–43% of neck length; female genital system amphidelphic, and tail elongate arcuate conoid. Dorylaimellus tropicus sp. nov. has a 0.6–0.7 mm long body; lip region rounded, offset; odontostyle 4–5 µm long, odontophore 8–10 µm long; hemizonid present; expanded part of pharynx 43–52% of neck length; female genital system amphidelphic and tail elongate-filiform, sudden tapering, ending with rounded tip. Dorylaimellus andrassyi, D. discocephalus, D. belondirelloides, D. chakpilus are redescribed based on the specimens collected from several localities of the Western Ghats.

Root-knot nematodes (RKN) (Meloidogyne spp.) represent one of the most damaging groups of plant-parasitic nematodes. They secrete effector proteins through a protrusible stylet to manipulate host cells for their benefit. Stylet-secreted effector proteins are produced within specialized secretory esophageal gland cells, one dorsal gland (DG) and two subventral glands (SvG), whose activity differ throughout the nematode life cycle. Previous gland transcriptomic profiling studies identified dozens of candidate RKN effectors but were focused on the juvenile stages of the nematode, when the SvGs are most active. We developed a new approach to enrich for the active DGs of M. incognita adult female RKN for RNA and protein extraction. Female heads were manually cut from the body, and a combination of sonication and vortexing was used to dislodge contents inside the heads. DG-enriched fractions were collected by filtering, using cell strainers. Comparative transcriptome profiling of pre-parasitic second-stage juveniles, female heads, and DG-enriched samples was conducted using RNA sequencing. Application of an established effector mining pipeline led to the identification of 83 candidate effector genes upregulated in DG-enriched samples of adult females that code for proteins with a predicted signal peptide but lack transmembrane domains or homology to proteins in the free-living nematode Caenorhabditis elegans. In situ hybridization resulted in the identification of 14 new DG-specific candidate effectors expressed in adult females. Taken together, we have identified novel candidate Meloidogyne effector genes that may have essential roles during later stages of parasitism. [Graphic: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Root-knot nematodes (RKNs) Meloidogyne spp. are extremely polyphagous pests and four species severely affect grapevines throughout the world: M. arenaria, M. incognita, M. javanica and M. ethiopica. Californian populations of M. arenaria and M. incognita are reported to be virulent to widely used rootstocks and to the rootstock ‘Harmony’ in particular. Breeding RKNs-resistant grape rootstocks is a promising alternative to highly toxic nematicides. Muscadine (Vitis rotundifolia syn. Muscadinia rotundifolia) is a resistance (R) source with undercharacterised genetics. To this end, we used a segregating progeny between the RKN-resistant Vitis x Muscadinia accession ‘VRH8771’ from the muscadine source ‘NC184-4’ and the RKN-susceptible V. vinifera cv. Cabernet-Sauvignon. We first phenotyped its resistance to isolates of the i) M. arenaria, ii) M. incognita and iii) M. javanica species, and then to iv) two mixed Harmony-virulent Californian populations of M. arenaria and M. incognita. Finally, we created an isolate of M. arenaria and M. incognita from these Harmony populations and phenotyped the progeny to each of them [v) and vi)], and to vii) an isolate of M. ethiopica. The resistance phenotype of all the progeny’s individuals was independent of the RKN isolates or populations used. Resistance was mapped in a region of chromosome 18 in VRH8771, supporting the hypothesis that it is conferred by a single gene with an unprecedented wide spectrum in grapevine, including Harmony-virulent isolates. This dominant gene, referred to as MsppR1, is linked to the telomeric QTL XiR4 for X. index resistance from the same source. Additionally, plant mortality data showed that MsppR1-resistant material expressed a high-level resistance to the Harmony-virulent isolates. Our results are a first step towards the development of marker-assisted breeding using SSR and SNP markers for resistance to RKNs in accession VRH8771.

Root-knot nematodes (RKN) (Meloidogyne spp.) constantly communicate with their host to establish and maintain specialized feeding cells. They likely regulate this interaction by monitoring host biology. As plant host biology is influenced by light and gene expression varies correspondingly, RKN gene transcription and biology likely follow similar patterns. We profiled RKN transcripts over a period of 24 h and identified approximately 1,000 differentially expressed genes (DEG) in nematode and model host Medicago truncatula, with the majority of DEG occurring in the middle of the dark period. Many of the plant DEG are involved in defense-response pathways, while the nematode DEG are involved in establishing infection, suggesting a strong host-nematode interaction occurring during the dark. To identify interacting genes, we developed a plant-nematode gene network based on DEG signals. The phenylpropanoid pathway was identified as a significant plant-nematode interacting pathway, representing four of 33 genes in the network. We further examined if this pathway interacts similarly in another host, tomato, by quantifying phenolic and flavonoid compounds produced by this pathway. Phenolic compounds showed a significant increase in production during the day in uninoculated plants as compared with during the night. However, during the dark period, there was an increase in flavonoid content in infected plants when compared with uninfected controls, indicating potential host defense mechanisms active during the height of nematode activity at night. This study elucidated cross-species interacting pathways that could be targeted to develop novel management strategies to these important pests.[Graphic: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Around 300 different plant species are infected by the plant-parasitic reniform nematode (Rotylenchulus reniformis), including cotton. This is a devasting nematode with a preference for cotton; it is commonly found in Alabama farms and causes severe reduction in yields. Its first internal transcribed spacer (ITS1) region can be sequenced, and potential mutations can be found in order to study the population dynamics of the reniform nematode. The goal of our study was to sequence the ITS1 rDNA region in male and female RNs that were collected from BelleMina, Hamilton, and Lamons locations in Alabama. After separating the single male and female RNs from the samples collected from the three selected listed sites above, the ITS1 region was amplified selectively using specific primers, and the resulting products were cloned and sequenced. Two distinct bands were observed after DNA amplification of male and female nematodes at 550 bp and 730 bp, respectively. The analysis of sequenced fragments among the three populations showed variation in average nucleotide frequencies of female and male RNs. Singletons within the female and male Hamilton populations ranged from 7.8% to 10%, and the variable sites ranged from 13.4% to 26%. However, female and male BelleMina populations had singletons ranging from 7.1% to 19.7% and variable regions in the range of 13.9% to 49.3%. The female and male Lamons populations had singletons ranging from 2.5% to 8.7% and variable regions in the range of 2.9% to 14.2%. Phylogenetic (neighbor-joining) analysis for the two ITS1 fragments (ITS-550 and ITS-730) showed relatively high intra-nematode variability. Different clone sequences from an individual nematode often had greater similarity with other nematodes than with their own sequences. RNA fold analysis of the ITS1 sequences revealed varied stem and loop structures, suggesting both conserved and variable regions in the variants identified from female and male RNs, thus underscoring the presence of significant intra- and inter-nematodal variation among RN populations in Alabama.

Six new and four known species of the genus Axonchium Cobb, 1920 are described and illustrated from the Western Ghats of India. Axonchium indicum sp. nov. has a 1.2–1.4 mm long body, offset lip region, 8–9 µm long odontostyle, expanded part of pharynx 39–49 % of total neck length, anterior uterine sac 0.9–1.6 times the mid-body diameter long, and a bluntly conoid tail. Axonchium microspiculum sp. nov. has a 1.1–1.22 mm long body, offset lip region, 7–8 µm long odontostyle, 20–23 µm long spicules, two weakly developed ventromedian supplements, and obtusely rounded tail. Axonchium nilgiriense sp. nov. has a 1.4–1.6 mm long body, offset lip region, 8–9 µm long odontostyle, vagina strongly bent posteriad, 37–41 µm long spicules, 3–4 ventromedian supplements, and bluntly conoid tail. Axonchium paracingulatum sp. nov. has a 2.5–2.8 mm long body, offset lip region, 10–11 µm long odontostyle, vaginal lumen highly expanded in the middle, 69 µm long spicules, and broadly conoid tail with rounded terminus. Axonchium tropicum sp. nov. has a 1.7–2.0 mm long body, offset lip region, 11–12 µm long odontostyle, anterior uterine sac 2.3–4.0 times the mid-body diameter long, 40 µm long spicules, 4 widely spaced ventromedian supplements, and broadly rounded tail. Axonchium uniqum sp. nov. has a 1.7–2.0 mm long body, offset lip region, 10–11 µm long odontostyle, anterior uterine sac 2.5–2.8 times mid-body diameter long, 68 µm long and slender spicules, and broadly conoid tail. Axonchium nitidum, A. saccatum, A. transkeiense and A. vallum are redescribed based on specimens collected from several localities. A diagnostic key to the identification of the valid species of this genus is provided.

Abstract The natural phytochemical latex of Euphorbia milii var. hislopii is one of the most promising natural molluscicides for the control of Biomphalaria glabrata, and has been widely studied under laboratory conditions for selective control of schistosomiasis transmission. However, the effect of this product on B. glabrata infected by other helminths had not yet been investigated. The present study reports evaluation of the effect of E. milii var. hislopii latex on the survival and reproductive activity of B. glabrata infected by Angiostrongylus cantonensis. For this purpose, the following groups were formed: control (C), exposed (E), infected (I) and infected and exposed for different time intervals (1 day - I+E-1D, 7 days - I+E-7D, 14 days - I+E-14D, 21 days - I+E-21D and 28 days - I+E-28D). The experimental infection was performed with L1 larvae of A. cantonensis and exposure to 0.08 mg/L (LC50) of E. milii latex for a period of 24 hours. We analyzed the effects of E. milii latex on the survival of snails during four weeks, reproductive parameters and possible histophysiopathological changes in the gonad and albumen gland of the snails. Regarding survival, there was reduction of more than 50% in the groups exposed to latex (E and I + E) compared to the control group. As for the number of ovigerous masses, eggs, and average number of hatched snails, significant increases were observed in the I+E-1D group at the 4th week compared to the control group and the other weeks in the same group. Angiostrongylus cantonensis larvae were observed in the gonad and albumen gland from day 21 and 28 of infection in groups I and I+E, respectively, with granuloma-like formation. At these observation periods and in these groups, an increase in galactogen was observed in the albumen gland, which influenced egg laying, suggesting the existence of a fecundity compensation mechanism phenomenon. It was possible to conclude that both stressors – A. cantonensis infection and exposure to E. milii latex – directly influenced the survival and reproductive parameters of B. glabrata.

Background. The presented information refers to the completed stage of the breeding process carried out at the Institute of Agrobiotechnologies (Syktyvkar) that led to the development of a new mid-early table potato variety – ‘Vychegodsky’. This cultivar was obtained from controlled crossing of cvs. Svitanok Kievsky × Amadeus. The new variety underwent a comprehensive assessment for the main agronomic traits and genetic screening for resistance to wart disease, nematode, and viruses X and Y.Materials and methods. In 2020, according to the results of production tests performed in 2017–2019, the description of the new cv. ‘Vychegodsky’ was finalized. The registered cv. ‘Nevsky’ was chosen as the reference. The study was conducted in the Institute’s experiment fields with a six-field crop rotation, which ensured high soil fertility without the use of mineral or organic fertilizers. The soil was soddy-podzolic. The planting scheme was 70 × 30 cm, at a depth of 8–10 cm, over the experimental plot area of 52.5 m2 (250 tubers), with four replications.Results. The mid-early cultivar ‘Vychegodsky’ is described as follows: the plant is erect, 50–65 cm in height; tubers are roundish-oval, with yellow skin color and light yellow flesh. The studies have shown that in its agronomic traits in the Republic of Komi cv. ‘Vychegodsky’ exceeds the reference cv. ‘Nevsky’. Its yield is 34.3 t/ha, and its marketable tuber weight 55.1 g; it contains 15.7% of starch, 24.1% of dry matter, and 11.2 mg% of vitamin C. The cultivar demonstrates high field resistance to major potato diseases, and genetically determined resistance to wart disease and golden potato nematode.Conclusion. Thus, a new potato cultivar has been released and included into the State Register of Selection Achievements (National List of the Russian Federation).

The co-occurrence of biotic and abiotic stresses in agricultural areas severely affects crop performance and productivity. Drought is one of the most adverse environmental stresses, and its association with root-knot nematodes further limits the development of several economically important crops, such as cowpea. Plant responses to combined stresses are complex and require novel adaptive mechanisms through the induction of specific biotic and abiotic signaling pathways. Therefore, the present work aimed to identify proteins involved in the resistance of cowpea to nematode and drought stresses individually and combined. We used the genotype CE 31, which is resistant to the root-knot nematode Meloidogyne spp. And tolerant to drought. Three biological replicates of roots and shoots were submitted to protein extraction, and the peptides were evaluated by LC-MS/MS. Shotgun proteomics revealed 2345 proteins, of which 1040 were differentially abundant. Proteins involved in essential biological processes, such as transcriptional regulation, cell signaling, oxidative processes, and photosynthesis, were identified. However, the main defense strategies in cowpea against cross-stress are focused on the regulation of hormonal signaling, the intense production of pathogenesis-related proteins, and the downregulation of photosynthetic activity. These are key processes that can culminate in the adaptation of cowpea challenged by multiple stresses. Furthermore, the candidate proteins identified in this study will strongly contribute to cowpea genetic improvement programs.

The application of antagonistic fungi for plant protection has attracted considerable interest because they may potentially replace the use of chemical pesticides. Antipathogenic activities confirmed in volatile organic compounds (VOCs) from microorganisms have potential to serve as biocontrol agents against pre- and post-harvest diseases. In the present study, we investigated Galactomyces fungi isolated from rotten leaves and the rhizosphere of cherry tomato (Lycopersicon esculentum var. cerasiforme). VOCs produced by Galactomyces fungi negatively affected the growth of phytopathogenic fungi and the survival of nematodes. Mycelial growths of all nine examined phytopathogenic fungi were inhibited on agar plate, although the inhibition was more intense in Athelia rolfsii JYC2163 and Cladosporium cladosporioides JYC2144 and relatively moderate in Fusarium sp. JYC2145. VOCs also efficiently suppressed the spore germination and mycelial growth of A. rolfsii JYC2163 on tomatoes. The soil nematode Caenorhabditis elegans exhibited higher mortality in 24 h in the presence of VOCs. These results suggest the broad-spectrum activity of Galactomyces fungi against various plant pathogens and the potential to use VOCs from Galactomyces as biocontrol agents.

Abstract Background Globodera rostochiensis belongs to major potato pathogens with a sophisticated mechanism of interaction with roots of the host plants. Resistance of commercial varieties is commonly based on specific R genes introgressed from natural populations of related wild species and from native potato varieties grown in the Andean highlands. Investigation of molecular resistance mechanisms and screening the natural populations for novel R genes are important for both fundamental knowledge on plant pathogen interactions and breeding for durable resistance. Here we exploited the Solanum phureja accessions collected in South America with contrasting resistance to G. rostochiensis. Results The infestation of S. phureja with G. rostochiensis juveniles resulted in wounding stress followed by activation of cell division and tissue regeneration processes. Unlike the susceptible S. phureja genotype, the resistant accession reacted by rapid induction of variety of stress response related genes. This chain of molecular events accompanies the hypersensitive response at the juveniles’ invasion sites and provides high-level resistance. Transcriptomic analysis also revealed considerable differences between the analyzed S. phureja genotypes and the reference genome. Conclusion The molecular processes in plant roots associated with changes in gene expression patterns in response to G. rostochiensis infestation and establishment of either resistant or susceptible phenotypes are discussed. De novo transcriptome assembling is considered as an important tool for discovery of novel resistance traits in S. phureja accessions.

Abstract Background Muscadine (Muscadinia rotundifolia) is known as a resistance source to many pests and diseases in grapevine. The genetics of its resistance to two major grapevine pests, the phylloxera D. vitifoliae and the dagger nematode X. index, vector of the Grapevine fanleaf virus (GFLV), was investigated in a backcross progeny between the F1 resistant hybrid material VRH8771 (Vitis-Muscadinia) derived from the muscadine R source ‘NC184–4’ and V. vinifera cv. ‘Cabernet-Sauvignon’ (CS). Results In this pseudo-testcross, parental maps were constructed using simple-sequence repeats markers and single nucleotide polymorphism markers from a GBS approach. For the VRH8771 map, 2271 SNP and 135 SSR markers were assembled, resulting in 19 linkage groups (LG) and an average distance between markers of 0.98 cM. Phylloxera resistance was assessed by monitoring root nodosity number in an in planta experiment and larval development in a root in vitro assay. Nematode resistance was studied using 10–12 month long tests for the selection of durable resistance and rating criteria based on nematode reproduction factor and gall index. A major QTL for phylloxera larval development, explaining more than 70% of the total variance and co-localizing with a QTL for nodosity number, was identified on LG 7 and designated RDV6. Additional QTLs were detected on LG 3 (RDV7) and LG 10 (RDV8), depending on the in planta or in vitro experiments, suggesting that various loci may influence or modulate nodosity formation and larval development. Using a Bulked Segregant Analysis approach and a proportion test, markers clustered in three regions on LG 9, LG 10 and LG 18 were shown to be associated to the nematode resistant phenotype. QTL analysis confirmed the results and QTLs were thus designated respectively XiR2, XiR3 and XiR4, although a LOD-score below the significant threshold value was obtained for the QTL on LG 18. Conclusions Based on a high-resolution linkage map and a segregating grapevine backcross progeny, the first QTLs for resistance to D. vitifoliae and to X. index were identified from a muscadine source. All together these results open the way to the development of marker-assisted selection in grapevine rootstock breeding programs based on muscadine derived resistance to phylloxera and to X. index in order to delay GFLV transmission.

Five new and six known species belonging to the genus Basirotyleptus collected from the Western Ghats, India, are described and illustrated. Basirotyleptus conicaudatus sp. nov. is characterized by having 0.42–0.44 mm long body; odontostyle 9.5–10.0 μm, odontophore 11.5–12.0 μm; pharyngeal bulb pear-shaped, 14–15% of total neck length; female genital system mono-opisthodelphic; tail conoid with acute terminus. Basirotyleptus constrictus sp. nov. is characterized by having 0.38–0.49 mm long body; perioral disc distinct; odontostyle 9–10 μm, odontophore 14–15 μm; pharyngeal bulb pear-shaped, 15–17% of total neck length; female genital system mono-opisthodelphic; tail rounded to conoid. Basirotyleptus goaensis sp. nov. is characterized by having 0.73–0.87 mm long body; odontostyle 13.0–14.5 μm, odontophore 15.0–17.5 μm; pharyngeal bulb pyriform, 16–18% of total neck length; female genital system mono-opisthodelphic; tail rounded. Basirotyleptus neocaudatus sp. nov. is characterized by having 0.31–0.44 mm long body; odontostyle 7.5–9.5 μm, odontophore 10–13 μm; pharyngeal bulb pear-shaped, 14–19% of total neck length; female genital system mono-opisthodelphic; tail conoid with acute terminus. Basirotyleptus siddiqii sp. nov. is characterized by having 0.36 mm long body; odontostyle 7.5–8.0 μm, odontophore 10.0–10.5 μm; pharyngeal bulb pear-shaped, 15–16% of total neck length; female genital system mono-opisthodelphic; tail conoid. Six known species viz., B. basiri, B. pini, B. nindei, B. ethiopicus, B. acus, B. minutus are also described and illustrated. Along with light microscopic study, line drawings, compendium and key to species of Basirotyleptus are also provided.

Chromolaena odorata (L.) R.M. King & H. Robinson is native to tropical America, and has naturalized in many other countries in tropical Asia, Austria, and West Africa. The species often forms dense thickets and reduces the native species diversity and population in the invasive ranges. The species is also considered as a noxious weed in agriculture fields, and listed in the 100 of the world’s worst invasive alien species. The characteristics of its life-history such as the seed production rate, growth pattern, and adaptative ability to the environmental conditions may contribute to the invasiveness of the species. Possible evidence of the defense capacity against the natural enemy, and the allelopathic potential against the competitive plant species for C. odorata has been accumulated in the literature over three decades. The extracts, residues, and/or rhizosphere soil of C. odorata increased the mortality of various insects and parasitic nematodes, and decreased their population. The extracts, residues, and/or rhizosphere soil of C. odorata also inhibited the germination and growth of several plant species including the indigenous plant species in the invasive ranges of C. odorata. Toxic substances, pyrrolizidine alkaloids were found in the leaves and flowers of C. odorata. These pyrrolizidine alkaloids may work as the defense agents against the natural enemies. Several potential allelochemicals such as flavonoids, phenolic acids, and terpenoids were also found in the plant extracts of C. odorata. Some of these compounds may work as allelopathic agents of C. odorata and inhibit the germination and growth of the competitive plant species. These characteristics of C. odorata for the defense function against their natural enemies such as insects and parasitic nematodes, and allelopathic potential against the competitive native plant species may contribute to the invasiveness and naturalization of C. odorata in the new habitats as invasive plant species. However, it is necessary to determine the concentration of these allelochemicals in the neighboring environment of C. odorata such as the rhizosphere soil since allelochemicals are able to work only when they are released into the neighboring environment. It is the first review article focusing on the defense function and allelopathy of C. odorata.

Five new and five known species of the genus Tylencholaimus de Man, 1876 are described from the Western Ghats of India. Tylencholaimus macroamphidius sp. nov. has a 0.61–0.85 mm long body, angular lips, large amphid, 8.0–9.0 μm long odontostyle, odontophore with asymmetrical basal knobs, pharyngeal bulb expanding gradually, female genital system mono-prodelphic, and a rounded to conoid tail. Tylencholaimus shamimi sp. nov. has a 0.57–0.71 mm long body, 6.0–7.0 μm long odontostyle, odontophore with basal thickening, pharyngeal bulb expanding gradually, female genital system amphidelphic and a convex-conoid tail. Tylencholaimus southindicus sp. nov. has a 0.44–0.55 mm long body, lip region with distinct labial disc, 4.5–5.5 μm long odontostyle, odontophore with minute basal knobs, pharyngeal expansion abrupt, female genital system mono-prodelphic, and a rounded-conoid to rounded tail. Tylencholaimus striatus sp. nov. has a 0.30–0.34 mm long body with distinctly striated cuticle, 5.0–5.5 μm long odontostyle, odontophore with minute basal knobs, pharyngeal bulb expanding abruptly, female genital system mono-prodelphic, and a conoid tail with bluntly rounded terminus. Tylencholaimus tamiliensis sp. nov. has 0.51–0.58 mm long body, 5.5–6.0 μm long odontostyle, odontophore with minute basal knobs, pharyngeal bulb expanding gradually, female genital system mono-prodelphic and tail rounded to conoid with sunken terminus. Five known species of the genus Tylencholaimus viz. T. mirabilis, T. teres, T. micronanus, T. ibericus and T. cosmos also recorded from the region and redescribed/illustrated.

Abstract Root-knot nematodes (RKNs) (Meloidogyne spp.) are well known disease problem causing major losses in vegetable crops. Although, chemical nematicides have been used as one of the primary means for controlling RKNs, reliance on these nematicides is associated with heavy costs and negative effects on human health and environment. In this research, the suppressing potential of 6 Iranian commercial fertilizers on RKNs was investigated in laboratory and greenhouse conditions as an alternative to reduce the use of chemical nematicides. For this purpose, M. javanica inoculum was thoroughly mixed with autoclaved sandy loam soil. Then, 6 fertilizers (biofertilizer, phosphate chemical fertilizer (phosphate), potassium chemical fertilizer (potassium), peat moss, vermicompost, and leaf mold) were added individually to the inoculated soil, according to the defined treatments. The nematicide Cadusafos was used as a positive control. A negative control was also included in the experiment (including no fertilizer and no nematicide). Four-leaf seedlings of the tomato (Super Chief cv.) were transferred to the pots filled using 2 kg of the treated soil. After 60 days, reproduction factor (RF), egg mass, and root galling of the nematode were recorded. The results showed that, fertilizer-treated soils had significantly (P≤0.05) lower root galling, egg mass, and RF compared to the negative control. After the nematicide treatment, the highest suppression capability on the RKN was obtained in treatments of phosphate, biofertilizer, potassium, vermicompost, peat moss, and leaf mold, respectively. It can be concluded that, replacing chemical nematicides with fertilizers may be considered as a successful nematode management in tomato fields.

Background. The article presents information on the results of screening potato cultivars for major commercial traits: earliness, high yield, high starch content, resistance to late blight (Phytophthora infestans (Mont.) de Bary), virus diseases and potato nematode (Globodera rostochiensis Woll. (Ro1)). Materials and methods. VIR’s collection of domestic and foreign potato cultivars served as the material for this research. The study was conducted in accordance with the guidelines developed at the Potato Genetic Resources Department of VIR. Results and conclusion. The analysis of pedigrees helped to select source material for the main trends of domestic potato breeding. Data of a number of cultivars identified by analyzing progenies from self-pollination are presented in the paper. Potential sources of major commercial traits were found: cvs. ‘Banba’ (k-25222), ‘Bastion’ (k-25198), ‘Belukha’ (k-25146), ‘Charoit’ (k-25221), ‘Colleen’ (k-25224), ‘Gala’ (k-25270), ‘Geyzer’ (k-25266), ‘Gornyak’ (k-25311), ‘Larets’ (k-25211), ‘Leoni’ (k-25244), ‘Manifest’ (k-25265), ‘Meteor’ (k-25212), ‘Nur-Alem’ (k-25253), ‘Prizer’ (k-25217), etc. were identified as high yield sources; cvs. ‘Aktyubinskiy-2’ (k-25300), ‘Alaya roza’ (k-25144), ‘Charaўnik’ (k-25139), ‘Darnitsa’ (k-25179), ‘Lad’ (k-25180), ‘Levada’ (k-25121), ‘Maksimum’ (k-25136), ‘Palitra’ (k-25123), ‘Tamyz’ (k-25307), ‘Universal’ (k-25137), ‘Vektor’ (k-25200), ‘Vytok’ (k-11897), ‘Zarevo’ (k-10773) and ‘Zholbarys’ (k-25155) as sources of high starch content; cvs. ‘Aral’ (k-25107), ‘Aymurat’ (k-25248), ‘Bastion’ (k-25198), ‘Berkut’ (k-25250), ‘Gastsinets’ (k-25264), ‘Musinskiy’ (k-25312), ‘Nur-Alem’ (k-25253), ‘Rapsodiya’ (k-25130), ‘Senim’ (k-25306), ‘Sunkar’ (k-25258), ‘Tamyz’ (k-25307), ‘Udovitskiy’ (k-25260), ‘Vektor’ (k-25200), ‘Velikan’ (k-25201), ‘Zholbarys’ (k-25155) and ‘Zvezdochka’ (k-25209) as sources of late blight resistance; cvs. ‘Adil’ (k-25112), ‘Azart’ (k-25196), ‘Bastion’ (k-25198), ‘Charoit’ (k-25221), ‘Favorit’ (k-25132), ‘Gastsinets’ (k-25264), ‘Geyzer’ (k-25266), ‘Krasavchik’ (k-25210), ‘Maksimum’ (k-25136), ‘Malyshok’ (k-25189), ‘Manifest’ (k-25265), ‘Nadezhda’ (k-25213), ‘Nur-Alem’ (k-25253), ‘Pamyati Lorkha’ (k-25214), ‘Rapsodiya’ (k-25130), ‘Senim’ (k-25306), ‘Sirenevyy tuman’ (k-25143), ‘Sultan’ (k-25131), ‘Shchedrik’ (k-25126), ‘Tekes’ (k-25173), ‘Velikan’ (k-25201), ‘Volat’ (k-25263), ‘Zhemchuzhina’ (k-25128), etc. as sources of field resistance to virus diseases. Cultivars combining resistance to potato cyst nematode (Globodera rostochiensis Woll. (Ro1)) with other valuable commercial traits were also identified.

Abstract Background Leucine-rich repeat (LRR)-containing genes are involved in responses to various diseases. Recently, RNA-seq data from A. duranensis after nematode (Meloidogyne arenaria) infection were released. However, the number of LRR-containing genes present in A. duranensis and the response of LRR-containing genes to nematode infection are poorly understood. Results In this study, we found 509 amino acid sequences containing nine types of LRR domains in A. duranensis. The inferred phylogenetic relationships revealed that the nine types of LRR domains had two originations. The inferred selective pressure was mainly consistent with LRR domains undergoing purifying selection. Twenty-one LRR-containing genes were associated with possible resistance to nematode infection after 3, 6, and 9 days. Among them, Aradu.T5WNW, Aradu.JM17V, and Aradu.MKP1A were up-regulate at these three time points, while Aradu.QD5DS and Aradu.M0ENQ were up-regulated 6 and 9 days after nematode infection. The expression of the above mentioned five genes was significantly and negatively correlated with the number of LRR8 domain, indicating that fewer LRR8 domains are associated with the promotion of LRR-containing genes that resist nematode infection. Patterns of co-expression and cis-acting elements indicated that WRKY possibly regulate the responses of LRR-containing genes to nematode infection and that expansin genes may work together with LRR-containing genes in response to nematode infection. Conclusions We identified the number and type of LRR-containing genes in A. duranensis. The LRR-containing genes that were found appear to be involved in responses to nematode infection. The number of LRR8 domains was negatively correlated with expression after nematode infection. The WRKY transcription factor may regulate resistance to nematode infection based on LRR-containing genes. Our results could improve the understanding of resistance to nematodes and molecular breeding in peanuts.

Keywords: biotic interaction; developmental modification; plant development; nematode; insects; parasitic plants; legume-rhizobia symbiosis EN biotic interaction developmental modification plant development nematode insects parasitic plants legume-rhizobia symbiosis N.PAG N.PAG 4 11/25/20 20201123 NES 201123 In many ecosystems, plants represent the center of biological interactions. Plant-parasitic nematodes (PPN), which include cyst nematodes and gall-inducing root-knot nematodes, are both scourges for agriculture and interesting case studies for such host manipulations. Biotic interaction, developmental modification, plant development, nematode, insects, parasitic plants, legume-rhizobia symbiosis. [Extracted from the article]

The intensification of agriculture has created concerns about soil degradation and toxicity of agricultural chemicals to non-target organisms. As a result, there is great urgency for discovering new ecofriendly tools for pest management and plant nutrition. Botanical matrices and their extracts and purified secondary metabolites have received much research interest, but time-consuming registration issues have slowed their adoption. In contrast, cultural practices such as use of plant matrices as soil amendments could be immediately used as plant protectants or organic fertilizers. Herein, we focus on some types of soil amendments of botanical origin and their utilization for nematicidal activity and enhancement of plant nutrition. The mode of action is discussed in terms of parasite control as well as plant growth stimulation.

The structure of wheat roots of the "susceptible" variety Capa and "resistant" variety AUS 10894 infested by Heterodera avenae was studied. The processes leading to the formation of syncytia and the range of reactions of the studied varieties to infection are described. In both varieties, necrosis of cells surrounding the nematode, and in the wheat variety AUS 10894, in addition, necrotic changes in cells surrounding syncytia were found. The syncytia formed in the resistant variety degenerated early. The cells adjacent to the syncytia underwent divisions. Cell divisions also took place in the pericycle. They led to the formation of more numerous lateral roots, especially in plants from the susceptible variety. It seems that the earlier degeneration of syncytia and the accompanying necrotic changes in the tissues surrounding the syncytia observed in wheat of the AUS 10894 variety can be taken as signs of host resistance reactions.