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The increased demand for agricultural produce can be attained by optimizing the productivity potential and minimizing losses caused by notorious plant-parasitic nematodes (PPNs) in crops. Given the exacerbation of the environmental pollution problem with pesticides, the use of potential biocontrol agents is the most acceptable way of nematode management by the farming community. This study conducted a survey to evaluate three animal [chicken (3.0 g/plant), sheep (5.0 g/plant), and cow (5 g/plant)] manures on soil nematode communities on cucumber under greenhouse conditions and inoculated with plant growth-promoting rhizobacteria (PGPR) and their infectivity and the plant growth and crop production of tomato under field conditions compared to oxamyl (0.3 mL/plant). The survey concluded to spread 10 PPN genera, free-living nematodes (FLNs; Genus: Rhabditis), and predacious nematodes (PNs; Order: Mononchida). The root-knot nematode Meloidogyne spp. occupied the highest population density (PD; 60.41%), followed by the lesion nematode Pratylenchus spp. (38.72%) and then the spiral nematodes Helicotylenchus spp. (9.89%) and Tylenchus spp. (9.54%). The frequency of occurrence of phytonematode genera illustrated that Meloidogyne (35.41%), Pratylenchus (17.18%), Tylenchorhynchus (15.62%), and Tylenchus (11.45%) were the most frequent genera of phytonematodes. The higher prominence value was recorded with Meloidogyne, followed by Pratylenchus and Tylenchus. Under greenhouse conditions, an increase in plant growth parameters was recorded in cucumber plants that received the recommended rate of chicken, cow, and sheep manures, with no significant differences between chicken manure and oxamyl in root length and stem diameter. However, chicken manure treatment surpassed oxamyl in fresh root weight. Animal manure effects were extended for a long period in protective cucumber plants compared to control treatment by recording the lowest PD of Helicotylenchus spp., Tylenchorhynchus spp., and Pratylenchus spp. and the maximum decrease in galling and reproduction of Meloidogyne incognita. In the field experiment, test manures and PGPR combinations achieved maximum enhancement in tomato yield/plant compared to animal manures alone. The minimized numbers of M. incognita population coincided with the sustainable numbers of FLNs and PNs. Thus, the application of animal manures mixed with PGPR is a potential alternative to pesticides for the biological control of nematodes.

Plant-parasitic nematodes (PPNs), also known as phyto-parasitic or plant-destructive nematodes are microscopic, translucent, bilaterally symmetrical, pseudocoelomic, multicellular worm-like organisms which feed on plant root mostly, and seldom on other vegetative parts. Although these PPNs have been reported to constitute threat to rice production, documentation of their spatial distribution and densities in major rice-producing areas of Benue state, Nigeria is absent. Using multi-stage sampling procedure, surveillance for PPNs, their densities and community analyses were conducted in six major rice-producing local government areas (LGAs) of Benue. The LGAs included Agatu, Apa, Gwer West, Guma, Kwande and Makurdi LGAs and a total of 108 samples were collected comprising 54 soil and 54 root samples. Nine plant-parasitic nematode genera which included Criconemoides, Tylenchorhynchus, Trichodorus, Hirschmanniella, Xiphinema, Helicotylenchus, Scutellonema, Pratylenchus and Meloidogyne were recovered. In order of ranking, Meloidogyne sp., P. zeae and H. oryzeae had the highest population densities across all LGAs included in the study. The highest density of PPN was recorded in Kwande (ca. 133 PPNs/10mL of nematode suspension) while lowest population density was recorded in Makurdi (ca. 77 PPNs/10mL of suspension). Although Meloidogyne sp. recorded the highest average population density in all LGA except in Gwer West LGA where H. oryzae recorded the highest average population density of approximately 13 PPNs/10mL of suspension. Community analysis also revealed that Meloidogyne sp. was the most spatially distributed PPN closely followed by P. zeae and H. oryzae with prominence values of 37.78, 21.84 and 20.91, respectively. However, in the soil, the highest prominence value was recorded in H. oryzae making it the most spatially distributed PPN in the soil.

Tylenchorhynchus clarus Allen, 1955 (Figure 5, Table 4), Published as part of Azizi, Kourosh, Eskandari, Ali, Karegar, Akbar, Ghaderi, Reza, Elsen, Sven Van Den, Holterman, Martijn & Helder, Johannes, 2022, Analyses of morphological and molecular characteristics of Telotylenchinae from Iran point at the validity of the genera Bitylenchus and Sauertylenchus, pp. 425-446 in Zootaxa 5169 (5) on page 435, DOI: 10.11646/zootaxa.5169.5.2, http://zenodo.org/record/6952625, {"references":["Allen, M. W. (1955) A review of the nematode genus Tylenchorhynchus. University of California Publications in Zoology, 61, 129 - 165."]}

Tylenchorhynchus microconus Siddiqi, Mukherjee and Dasgupta, 1982 (Figurs 6, Table 4), Published as part of Azizi, Kourosh, Eskandari, Ali, Karegar, Akbar, Ghaderi, Reza, Elsen, Sven Van Den, Holterman, Martijn & Helder, Johannes, 2022, Analyses of morphological and molecular characteristics of Telotylenchinae from Iran point at the validity of the genera Bitylenchus and Sauertylenchus, pp. 425-446 in Zootaxa 5169 (5) on page 439, DOI: 10.11646/zootaxa.5169.5.2, http://zenodo.org/record/6952625, {"references":["Siddiqi, M. R., Mukherjee, B. & Dasgupta, M. K. (1982) Tylenchorhynchus microconus n. sp., T. crassicaudatus leviterminalis n. subsp. and T. coffeae Siddiqi and Basir, 1959 (Nematoda: Tylenchida). Systematic Parasitology, 4, 257 - 262. https: // doi. org / 10.1007 / BF 00009626"]}

Our study aimed to assess the structure and distribution of plant-parasitic nematodes in soybean [Glycine max (L.) Merr] in the south of Brazil. High taxonomical diversity was found, with records of 10 genera of plant-parasitic nematodes (PPNs), including important pests, such as Meloidogyne (mostly M. javanica with small esterase variability), Pratylenchus (mostly P. brachyurus) and Helicotylenchus spp. The Shannon-Weaver index (H′) ranged from 0 to 1.23 (mean = 0.37), whereas Pielou’s evenness (J) ranged from 0 to 1 (mean = 0.51). The amount of PPNs (0 to 22,050 per 250 cm3 soil, and 0 to 15,500 per 10 g roots), incidence and abundance for Meloidogyne (28.6%; 50 to 19,250 per 250 cm3), Pratylenchus (45.1%; 50 to 550 per 250 cm3), Helicotylenchus (91.2%; 50 to 9,150 per 250 cm3), Tylenchus (34.1%; 50 to 550 per 250 cm3), Xiphinema (33%; 50 to 250 per 250 cm3), Mesocriconema (15.4%; 50 to 2,000 per 250 cm3), Rotylenchus (8.8%; 50 to 1,900 per 250 cm3), Hemicycliophora (1.1%; 50 per 250 cm3), Discocriconemella (1.1%; 950 per 250 cm3) and Tylenchorhynchus (1.1%; 50 per 250 cm3) were related differently to the bioclimatic variables under analysis. Our findings provide an update for the status of PPNs in the south of Brazil and suggest important epidemiological issues linked to the management of these pests in the near future.

The purpose of the research is studying the species composition and control measures against parasitic nematodes of wild and cultivated subtropical fruit plants of Central Asia.Materials and methods. We studied subtropical fruit crops in 198 farms and 1985 household plots located in various soil and climatic zones of over 20,675 hectares in Central Asia. The materials were collected in the autumn (September-October), spring (April-May) and summer (June-August) months in 1970–1990 by the route method. Study subjects were plant parasitic nematodes of 8 species of wild and cultivated subtropical fruit plants in the Central Asian republics. A modified Baermann funnel method was used to isolate plant nematodes from plants and soil near roots. In total, we collected and analyzed more than 5,400 plant and soil samples. To identify the species of plant parasitic nematodes, we used the Atlas of plant parasitic nematodes compiled at the Institute of Parasitology of the Russian Academy of Sciences, as well as morphometric indicators obtained according to the generally accepted De Mann formulae.Results and discussion. More than 129,000 specimens of plant parasites of 98 species were found in the studied wild and cultivated subtropical fruit crops and soil near their roots. In many farms of the Central Asian republics, we found southern root-knot nematodes, peanut root-knot nematodes, javanese root-knot nematodes, and cotton root-knot nematodes in mixed populations. In Uzbekistan, the prevalence in these crops was from 8 to 61.3%, in Tajikistan – from 78 to 98%, in Turkmenistan – from 6 to 98%, and in Kyrgyzstan – 33%. In addition to root-knot nematodes, representatives of ecto- and endoparasites of the genera Tylenchorhynchus, Merlinius, Quinisulcius, Rotylenchus, Helicotylenchus, Pratylenchus, Paratylenchus, Macroposthonia, Labocriconema and Xiphinema were parasitizing in the above subtropical cultures. Under production conditions, we tested Furadan at a dose of 40 kg/ha, Heterophos at a dose of 60 and 120 kg/ha, and Aldicarb at a dose of 40 kg/ha to control root-knot and other parasitic nematodes. Their efficacy ranged from 89 to 100%. We also used the soil solarization method developed by us, the efficacy of which was 95–98%.

A survey of nematode community in grapevine plantations grown in Belbes, Sharqia, Egypt revealed the presence of nine plant-parasitic nematodes genera namely Aphelenchus, Criconemoides, Ditylenchus, Helicotylenchus, Pratylenchus, Meloidogyne, Longidorus, Tylenchus and Tylenchorhynchus; free-living nematodes (FLNs) belonging to the genus Rhabditis and predacious nematodes (PNs) belonging to order Mononchida. Nematodes were found with a different frequency of occurrence and population density. Pratylenchus gained a high population density (PD) followed by Tylenchus, Meloidogyne and Helicotylenchus. A higher prominence value (PV) was found with genus Pratylenchus (190.75) while, the genera Meloidogyne, Tylenchorhynchus and Tylenchus were found with moderate prominence values. Animal manures are effective tools in sustainable soil health and agricultural systems. Therefore, the influence of three livestock manures as feasible practices with BECTO Grow Roots®, a commercial plant growth-promoting bacterium (PGPB) on nematode community and plant growth and fruit yield of grapes, Vitis vinifera L. cv. Flame was undertaken. Soil samples were collected at five-time intervals. Composted animal manures significantly (P ≤ 0.05) minified numbers of plant-parasitic nematodes (PPNs). The greatest effect was recorded with oxamyl after two months of treatments followed by chicken, sheep and cow manure. Conversely, at four and five months after application, animal manures were the most effective. Moreover, a noticeable abundance of FLNs and PNs numbers was detected. The highest increment was achieved in soil amended with chicken manure followed by sheep and cow manure whereas oxamyl reduced numbers of FLNs and PNs as compared with untreated vines. Application of manures against PPNs particularly M.incognita decreased numbers of J2/250/soil in vines amended with chicken, cow and sheep manure, respectively and increased numbers of FLNs and PNs. Population densities of M.incognita J2/250 g soil were significantly minimized (1.55 J2/250 g soil) in blocks amended with commercial rhizobacteria and chicken manure. Maximum total fruit weight and leaf numbers were achieved in vines treated with rhizobacteria +chicken, cow and sheep manure, respectively. This study proved that composted chicken, cow and sheep manure applied alone or in combination with PGPB can be a promising tool for the management of phytoparasitic nematodes, enrichment of FLNs and PNs and improvement of plant growth and grapevine yield.

A survey of plant-parasitic nematodes (PPNs) associating wheat in Ismailia governorate, north eastern Egypt was carried-out during 2016/2017 and 2017/2018 growing seasons. Results showed that seven PPNs genera and/or species were found associating wheat roots. These genera and/or species, in descending order of frequency, were: Tylenchorhynchus spp. (14%), Helicotylenchus spp. (10%), Heterodera avenae (8%), Ditylenchus spp. (5%), Meloidogyne javanica (4%), Pratylenchus spp. and Xiphinema spp. (3%, each). Two screening pot experiments, in two consecutive growing seasons (2016/2017 and 2017/2018) were carried out to determine the host suitability of 15 Egyptian cereal cultivars including bread wheat ( Triticum aestivum ), barley ( Hordeum vulgare ) and oat ( Avena sativa ) to the cereal cyst nematode, Heterodera avenae , under greenhouse conditions. Results of both experiments were very similar and showed that oat cv. Baladi and wheat cv. Giza 171 were highly susceptible, while wheat cvs. Masr 1, Masr 2, Masr 3, Sakha 95, Seds 1, Seds 12, and Shandawel 1 were susceptible. However, barley cvs. Giza 135, Giza 123, Giza 124, and Giza 125 were found to be moderately resistant to the tested nematode. H. avenae suppressed ( P ≤ 0.05) the dry weights of roots, shoots and spikes of the inoculated plants, compared to the non-inoculated checks. Another greenhouse pot experiment was carried out during the wheat-growing season 2018/2019 to determine the effect of different initial population densities (Pi) of H. avenae on the growth parameters of wheat cv. Giza 171 and on nematode reproduction. Results showed that as the nematode Pi increased, both the wheat growth parameters and the nematode reproduction factor (Rf) were decreased ( P ≤ 0.05).

A nematode survey was conducted in Alexandria, El-Behera, El-Gharbia, El-Monufia and Kafr El-Sheikh governorates in northern Egypt during the 2017 – 2019 cropping seasons to study the occurrence, population density and host association of plant parasitic nematodes associated with spinach, Swiss chard and table beet. A total of 854 soil and root samples were collected from the rhizosphere of the surveyed vegetable crops. The surveyed governorates and their respective numbers of soil samples were as follows: Alexandria 230, El-Behera 206, El-Gharbia 138, El-Monufia 211 and Kafr El-Sheikh 69 samples. Plant parasitic nematodes in the collected soil and root samples were extracted, identified, and counted under the compound light microscope. The collected soil and root samples contained mixed populations of 15 genera and 18 species of phytoparasitic nematodes that are reported for the first time on spinach, Swiss chard and table beet in Egypt. The root-knot nematode(Meloidogyne spp.) with 37 – 67 frequency of occurrence (FO) were the most frequently encountered group of nematodes, followed by spiral (Helicotylenchus sp.), cyst (Heterodera sp.), lesion (Pratylenchus sp.) and stunt (Tylenchorhynchus sp.) with 15 – 61 FO. The genera Criconema, Criconemella and Tylenchus were quite common. However, the other genera (Ditylenchus, Hoplolaimus,Psilenchus,Rotylenchulus, Rotylenchus,Trichodorus, and Xiphinema) were less common. The nematode species Meloidogyne arenaria, M. incognita, M. javanica, Heterodera schachtii and H. trifolii were identified on spinach, Swiss chard and table beet roots. The occurrence of the cyst nematodes H. schachtii and H. trifolii on spinach, Swiss chard and table beet are new records in Egypt. Also, survey results revealed new host plant records for most of the identified nematode genera and species in Egypt.

Water shortages have increased Egyptian growers interest towards drip irrigation. Conventional and drip, are two types of irrigation systems which wereselected to investigate their effect on the fluctuation of the populations of some plant parasitic nematodes on growth of different vegetable host plants: tomato(Lycopersicon esculentum), eggplant(Solanum melongena), peppers(Capsicum annum), cucumber(Cucumis sativus), and cowpea(Vigna sinenses). The predominant genera of plant parasitic nematodes recovered from soil samples (Pi & Pf) were Meloidogyne, Helicotylenchus, Pratylenchus, Paratylenchus, Rotylenchulus, Hoplolaimus, Tylenchorhynchus,and Xiphinema. On the whole the results showed that, Meloidogyne and Pratylenchus were the most common plant parasitic nematode in the plant hosts (cucumber tomatoeggplant peppers cowpea) and the nematode population were lesser in drip irrigated plants (97.3, 69.0, 87.0, 81.0, 83.3 and 71.3, 46.7, 69.7, 59.0 63.0) respectively, than those of conventional irrigation (104.3, 83.7, 93.0, 85.7, 88.0 and 75.3, 68.0, 80.3, 64.0, 72.3) respectively. We can conclude that, the drip irrigation system can be used as a Strategy of nematode pests in combination with different strategies without greatly affecting on the crop growth.

Two populations of Tylenchorhynchus annulatus, recovered from loamy-soil rhizosphere of Zoysia japonica from Korea are described and illustrated based on integrative taxonomy, considering both morphological and molecular phylogenetic inferences from analyses of the 28S-rRNA and ITS-rRNA gene sequences. One of the populations manifested variation in species diagnostic characters; continuous lateral field incisures past the phasmid was not a constant character in all specimens examined, with some specimens manifesting fusion of inner incisures of the lateral field below the level of the phasmid and incomplete areolation of the lateral fields. The fusion of the inner incisures of the lateral field past the phasmid level is therefore a variable character within the group, and when used alone, may not be taxonomically reliable to delineate species within the genus. This is molecularly supported by genetic resemblance of the two populations with other characterized T. annulatus isolates based on D2-D3 expansion segment and ITS-rRNA. The overlapping disparities between the two populations are therefore herein treated as intraspecific variations within T. annulatus populations. Furthermore, comparison within all the published sequences of T. annulatus are made and recommendations for sequence corrections are given. Tylenchorhynchus thermophilus is characterized herein for the first time in Korea while T. annulatus and T. claytoni are molecularly confirmed.

Plant-parasitic nematodes (PPNs) are considered serious damaging on the global cereals production systems. The current study was conducted to evaluate the incidence of PPNs in the main cereal-growing areas in northern Kazakhstan. PPNs were detected in about 90% of 78 soil samples and thirteen genera were identified, including Pratylenchus, Heterodera, Geocenamus, Ditylenchus, Helicotylenchus, Rotylenchus, Pratylenchoides, and Tylenchorhynchus. Out of the 78 samples, 32 samples were found infested by Heterodera filipjevi based on the morphological and molecular analysis. To our knowledge, this is the first report on this cereal cyst nematode species in northern Kazakhstan. During the morphological and molecular assays, intraspecific polymorphism was observed within H. filipjevi populations and the populations divided into at least two groups. The highest frequency of infestation of H. filipjevi (76%) was recorded from Kokshetau Province when compared to other provinces: Astana (50%), Petropavl (37%), and Kostanay (16%). The highest number of cysts (30.4) was found among Astana samples while the lowest number of cysts (18.2) was recorded from Kostanay samples. Cyst nematodes can maintain their population above the economic threshold as stimulated by the cereal monoculture system (mainly wheat) which is similar to the cereal production systems of northern Kazakhstan.

A field trial was conducted in rice (Pusa Basmati 1121) ecosystem to evaluate the effect of vermicompost (VC), FYM, phosphate solubilising bacteria (PSB) and crop residue (CR) and crop rotation with mungbean (Vigna radiata) on plant-parasitic and bacterivorous nematodes. The rice root nematode, Hirschmanniella oryzae was the predominant plant-parasitic nematode (0–750/250cc soil), followed by Heterodera cajani juveniles (0–625/250cc soil) in mung plots, stunt nematode, Tylenchorhynchus sp. (0–150/250cc soil) and dorylaimids (0–540/250cc soil). The bacterial feeders varied from 50–1800/250cc soil. The population densities of the nematode were low in treatments with VC (T3), VC + CR (T5) and VC + CR + PSB (T7), indicating an antagonistic effect of vermicompost on the nematode. The highest densities of bacterivorous nematodes were observed in plots with vermicompost + crop residue (T5). The population densities of H. oryzae were significantly high (50–1110/250cc soil) in treatments with FYM (T2), or treatments with FYM + CR (T4) and treatments with FYM + CR + PSB (T6), indicating that both FYM and2crop residue did not have an antagonistic effect on the rice root nematode. The plant parasitic index was low in all treatments that had a high saprozoic nematode index.

Morphological and molecular analyses of plant-parasitic nematodes (PPN) from 12 sugarcane plantation sites of Tanganyika Planting Company (TPC) Limited in Kilimanjaro region of Tanzania revealed the presence of six PPN genera, i.e. Helicotylenchus, Hemicycliophora, Pratylenchus, Rotylenchulus, Scutellonema, and Tylenchorhynchus. The genera with the highest densities and present in virtually all samples were Pratylenchus and Rotylenchulus, and the most important species appeared to be R. parvus, P. zeae, T. crassicaudatus, and T. ventrosignatus. A total sequences of 11 partial ITS, 15 D2-D3 of 28S, and 6 partial 18S of rRNA gene, and 7 partial COI gene of mtDNA of these species were obtained in this study. Morphology and molecular data comparisons between the Tanzanian R. parvus and the South African R. parvus indicated that R. parvus is a cryptic species complex. Based on the results of morphological and molecular analyses of T. crassicaudatus and T. agri from China, Haiti, Indonesia, Iran, Niger and the USA, T. agri syn. n. is proposed as a junior synonym of T. crassicaudatus. Morphological and molecular analyses of plant-parasitic nematodes (PPN) from 12 sugarcane plantation sites of Tanganyika Planting Company (TPC) Limited in Kilimanjaro region of Tanzania revealed the presence of six PPN genera, i.e. Helicotylenchus, Hemicycliophora, Pratylenchus, Rotylenchulus, Scutellonema, and Tylenchorhynchus. The genera with the highest densities and present in virtually all samples were Pratylenchus and Rotylenchulus, and the most important species appeared to be R. parvus, P. zeae, T. crassicaudatus, and T. ventrosignatus. A total sequences of 11 partial ITS, 15 D2-D3 of 28S, and 6 partial 18S of rRNA gene, and 7 partial COI gene of mtDNA of these species were obtained in this study. Morphology and molecular data comparisons between the Tanzanian R. parvus and the South African R. parvus indicated that R. parvus is a cryptic species complex. Based on the results of morphological and molecular analyses of T. crassicaudatus and T. agri from China, Haiti, Indonesia, Iran, Niger and the USA, T. agri syn. n. is proposed as a junior synonym of T. crassicaudatus.

Plant parasitic nematodes (PPNs) are a pathogenic group that causes momentous crop yield loss by retarding plant growth and development through plant parasitization. In this study, the distribution of PPNs based on the main crops in Guangxi Province of China was investigated. A total of 425 samples of soil or roots from sugarcane, rice, maize, and soybean were collected in 68 counties, and a total of 48 order/family/genera of PPNs were identified, of which some genera were found in more than one crop. A total of 31 order/family/genera of PPNs were found in rice, among which Hirschmanniella was the most abundant, accounting for 79.23%, followed by Tylenchorhynchus (34.43%). Forty order/family/genera were observed in maize, of which the dominant genera were Pratylenchus and Tylenchorhynchus at 45.14% and 32.64%, respectively. In addition, 30 order/family/genera of PPNs were detected from sugarcane, and the percentages of Tylenchorhynchus and Helicotylenchus were 70.42% and 39.44%, respectively. The main crop of Eastern ecological regions was rice, with a high frequency of Hirschmanniella. The greatest frequency of Pratylenchus was found in the Western eco-region, which had a large area of maize. In the Northern eco-region, rice and maize were popular, with abundant Hirschmanniella and Helicotylenchus. In the Central eco-region, Pratylenchus was detected on the main crop of sugarcane. Hirschmanniella (72.94%) was dominant in clay, and Tylenchorhynchus (54.17%) showed the highest frequency in loam. The distribution of PPNs varied with different altitudes. The diversity of this phenomenon was closely related to host plants. These results could improve understanding of the distribution of PPNs and provide important information for controlling PPNs.

Se determinaron los géneros de nematodos fitoparásitos asociados al cultivo de Tagetes erecta L. “marigold” sembrado en el distrito Virú, departamento La Libertad, Perú, y sus frecuencias y densidades poblacionales. Entre marzo y diciembre de 2002, fueron colectadas al azar muestras de suelo de cultivo y de raíces de plantas de T. erecta en 14 parcelas sembradas con esta especie vegetal. Las muestras de suelo se procesaron mediante la técnica de Christie y Perry y las de raíces mediante la de Baermann modificada en bandeja; también se realizó coloración de raíces. Se encontraron diez géneros de nematodos fitoparásitos asociados al cultivo de T. erecta en el distrito Virú; los cuales, según frecuencia descendente de parcelas con cada género en el suelo fueron: Criconemoides 85,7 %, Helicotylenchus 78,6 %, Tylenchus 78,6 %, Meloidogyne 71,4 %, Hemicycliophora 64,3 %, Aphelenchoides 57,1 %, Trichodorus 35,7 %, Paratylenchus 28,6 %, Tylenchorhynchus 28,6 % y Pratylenchus 21,4 % y en las raíces: Meloidogyne 64,3 %, Helicotylenchus 42,9 % y Criconemoides 28,6 %. Los tres primeros presentaron las densidades poblacionales más altas. Meloidogyne fue el único encontrado dentro del tejido de algunas raíces noduladas, aunque mayormente como formas inmaduras y la producción de huevos fue nula o escasa.

A sum of 218 composite rhizosphere soil samples were collected from around the feeder roots of mango, Mangifera indica growing in Jazan region, the tropical south west corner of Saudi Arabia. Samples were rendered for nematodes extraction using the centrifugal floatation method, and the stylet-bearing nematodes were morphologically identified according to the standardized taxonomical keys. A list of 14 stylet-bearing nematode genera and/or species were found to be associating the roots of mango in this study. Species identification of the most important parasitic nematodes, in this list, was carried-out, based on morphometrics and morphological features. Identification of these species was then molecularly confirmed using the D3 expansion region of 28S ribosomal RNA (rRNA) gene. These nematodes included; Tylenchorhynchus mediterraneus, Hoplolaimus seinhorsti, Hemicriconemoides strictathecatus, Longidorus latocephalus and Xiphinema elongatum. Some new local nematode-host records in Saudi Arabia were recorded including; Aphelenchus sp., H. strictathecatus, L. latocephalus, and T. mediterraneus. Some new world nematode-host records were also reported including; L. latocephalus and T. mediterraneus. Keywords: Mangifera indica, Morphometrics, Molecular, Stylet-bearing nematodes, Saudi Arabia

An intensive field study was carried out during the period from December, 27th 2016 to November, 3rd 2017 to survey nematode associations of doum palm trees, Hyphaene thebaica in Aswan governorate, Southern Egypt. In this regard, a total of 105 composite rhizosphere soil and root samples were collected from different provinces (Aswan, Daraw, Edfu and Kom Ombo) belonging to Aswan governorate. Nematodes were extracted by Cobb’s wet-sieving and centrifugal sugar flotation techniques and identified to the genus level according to the original body descriptions and standard identification keys of plant-parasitic nematodes. Fourteen genera were found to be associated with the rhizosphere of doum palms and could be descendly arranged based on their frequency of occurrence (FO%) as follows: Meloidogyne (46.7%), Rotylenchulus (33.3%), Helicotylenchus (27.6%), Aphelenchus (17.1%), Tylenchus (14.3%),Hemicriconemoides (12.4%), Tylenchorhynchus (9.5%), Ditylenchus (8.6%), Aphelenchoides (7.6%), Pratylenchus (6.7%), Trichodorus (5.7%), Criconemella (4.8%), Paratylenchus (3.8%) and Hoplolaimus (2.9%). It was clearly noticed that root-knot (Meloidogyne), reniform (Rotylenchulus) and spiral (Helicotylenchus) nematodes appeared to be the most prominent genera recording high prominence value (PV) reaching 3444, 2816 and 1902, respectively and population density (PD) 504, 488 and 362 nematodes/250 cc3 soil, consequently, whereas the rest genera were less prominent representing PV ranging between 109-595 with PD reaching 46-201 nematodes/250 cc3 soil. Examination of root samples revealed the presence of ideal root galling caused by Meloidogyne and their sedentary adult females were isolated and subjected to the traditional identification to the species level using perineal pattern test and reconfirmed by the biochemical and molecular identification methods. Meloiodogyne javanica appeared to be the predominant root-knot nematode species in this study. The current results updated the database of nematode associations with their plant hosts in Egypt and introduced doum palm as new host of M. javanica and probably to other nematodes.

Two field experiments were carried out to study the efficacy of different biological control agents in controlling certain plant-parasitic nematode species including Meloidogyne javanica, Tylenchorhynchus mediterraneus, Hoplolaimus seinhorsti, Longidorus latocephalus, and Xiphinema elongatum on guava and fig trees under the tropical field conditions of Jazan region, south-west Saudi Arabia during two successive seasons from Feb. 15, 2016 to Jan. 15, 2017. The evaluated bio-agents were used in different integrated management combinations of certain fungal species (Trichoderma harzianum, Verticillium chlamydosporium, and Purpureocillium lilacinum), the bacterium Pasteuria penetrans, some organic amendments (cow manure, compost, and chicken manure), urea 46% as a nitrogenous fertilizer, and the nematicide carbofuran 10G for comparison. Results showed that all the tested treatments gradually decreased (P ≤ 0.05) the population densities of plant-parasitic nematodes on guava and fig trees over the study period. The highest reduction of nematode densities occurred at the end of the experiment. Carbofuran 10G was the most effective treatment in suppressing the nematode densities on guava and fig trees. The most effective management combinations, next to carbofuran 10G, in suppressing the nematode densities in the rhizosphere of guava trees were P. lilacinum + P. penetrans + urea 46%, P. lilacinum + P. penetrans + chicken manure, and T. harzianum + P. penetrans + chicken manure (66.54–69.22% nematode reductions). Correspondent combinations in the rhizosphere of fig trees were P. lilacinum + P. penetrans + cow manure, T. harzianum + P. penetrans + cow manure, P. lilacinum + P. penetrans + urea 46%, and V. chlamydosporium + P. penetrans + urea 46% (54.68–57.17% nematode reductions). On the other hand, nematode population densities continued to increase (P ≤ 0.05) in the rhizosphere of guava and fig trees in the absence of nematode management combinations. All the tested treatments significantly increased (P ≤ 0.05) the number of fruits/tree on guava and fig trees. Treatments which included the combinations of fungal and bacterial parasites along with chicken manure gave the highest numbers of fruits/tree, followed by the treatment with the nematicide carbofuran 10G. Regression analysis showed a significant negative linear relationship between the number of nematodes/kg soil and the number of guava and fig fruits/tree.

Distribution and identification of phytonematodes associated with wheat grown in twelve provinces of Northern and Middle Egypt were investigated during two growing seasons (2016-2017 and 2017-2018). A total of 929 soil and root samples were collected from 119 localities (villages/farms) belonging to 37 districts. Samples contained fourteen nematode genera and species viz., Aphelenchoides, Criconemella, Ditylenchus, Helicotylenchus, Heterodera, Hirschmanniella oryzae, Hoplolaimus, Longidorus,Meloidogyne, Pratylenchus, Rotylenchulus reniformis, Tylenchorhynchus, Ttylenchus and Xiphinema. The stunt nematodes (Tylenchorhynchus spp.), the root-lesion nematodes (Pratylenchus spp.), the spiral nematodes (Helicotylenchus spp.) and the cyst nematodes (Heterodera spp.) were the most frequent nematodes in all samples. The stunt nematodes had the highest occurrence with 47.4%, population density with 48.2 and prominence value with 33.2. The root-lesion nematodes ranked the second after Tylenchorhynchus spp., in terms of frequency of occurrence (13.77%), while the cyst nematodes had the second order after the stunt nematodes, in terms of population density (24.8) and prominence value (5.4). The spiral nematodes occupied the third rank, in terms of frequency of occurrence (5.5%), and the last rank in terms of both of population density and prominence value (9 and 2.1, respectively).

Summary Plant-parasitic nematodes restrict crop growth and cause yield loss in field pea (dry edible pea). A 4-year survey of commercial pea fields was conducted in North Dakota, one of the leading producers of field pea in the USA, to investigate nematode distribution, prevalence, abundance and association with soil properties. Beginning in 2014, a total of 243 soil samples were collected from 16 counties, and soil properties of 115 samples were analysed to determine the association of nematodes with soil factors (texture, organic matter, nutrients). The plant-parasitic nematode genera, Paratylenchus (absolute frequency = 58-100%; mean density = 470-1550 (200 g soil)−1; greatest density = 7114 (200 g soil)−1) and Tylenchorhynchus (30-80%; 61-261; 1980, respectively), were the most frequent and widely distributed. Pratylenchus and Helicotylenchus were identified in one-third of the counties surveyed with mean densities ranging from 43 to 224 and 36 to 206 (200 g soil)−1, respectively. Xiphinema was found relatively frequently but at low densities. Hoplolaimus and Paratrichodorus were rarely detected at lower densities. Canonical correspondence analysis revealed that soil factors explained 19% of the total variance of nematode genera abundance. The relationship between nematode abundance and soil sand content and pH was significant, while clay, silt, organic matter and nutrients were not significantly related to nematode abundance. This is the first multi-year study investigating nematodes associated with field peas and their relationship with soil factors in a major field pea production region of the USA.

Summary We analysed the effect of the invasive perennial plant Heracleum sosnowskyi on soil nematode communities and diversity, and plant species composition, by comparing invaded and non-invaded (control) areas in natural conditions. Invasion of H. sosnowskyi caused significant shifts in plant species composition, which subsequently modified nematode assemblages. Stress-sensitive omnivores, fungivores and root-biomass-dependent obligate plant parasites best reflected changes in soil nematode communities under the influence of H. sosnowskyi invasion. The negative effect of H. sosnowskyi was most evident on Aphelenchus, Tylencholaimus, Geocenamus, Helicotylenchus, Pratylenchus, Tylenchorhynchus and Aporcelaimellus. Our results indicate that significant changes in the herbaceous layer after H. sosnowskyi invasion in ecosystems where H. sosnowskyi eventually became dominant impacted soil nematode communities but did not affect nematode diversity. This was in contrast to the habitats where a solitary plant of H. sosnowskyi grew and no significant changes in nematode communities were observed.

During a survey on the biodiversity of plant-parasitic nematodes in Khuzestan province (southwest Iran), Bitylenchus hispaniensis was discovered around the rhizosphere of the euphrates poplar tree. The morphological and morphometric data were provided for the recovered species. To the best of our knowledge, this is the first report of B. hispaniensis from Iran and for the first time in association with euphrates poplar worldwide. Molecular phylogenetic analyses of the Iranian population of B. hispaniensis using the D2-D3 expansion segments of 28S rDNA and internal transcribed spacer (ITS rDNA) sequences using Bayesian inference (BI), showed a maximally supported clade with other sequences of the species.