First report of Meloidogyne hapla on kiwifruit in South Africa

Plant-parasitic nematodes are the main nematodes that live in the soil, causing yield loss in various crops. As endoparasites, Pratylenchus species can reduce the yield of grass and other plants by feeding on their roots. Because of its parasitic nature on plants, this species requires careful identification; in South Africa's Limpopo Province, grasslands are among the most vital agricultural resources. Therefore, this molecular study was conducted in 2023 at Limpopo University to identify the nematode from South Africa's soils using 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. The nematode was identified as Pratylenchus. Afterward, 28S rDNA was amplified using specific primers to identify the nematode at the molecular level. The Nblast analysis based on the large subunit ribosomal DNA showed South African Pratylenchus had 99% similarity (OQ343703) with the South African population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as Pratylenchus in the same clade with highly supported (100) bootstrap values. In conclusion, this species was identified using 28S rDNA; however, other rDNA markers, such as ITS rDNA and mtDNA is recommended for a better understanding of Pratylenchus phylogeny.

Plant-parasitic nematodes are the main nematodes that live in the soil, causing yield loss in various crops. Since Xiphinema oxycaudatum is an ectoparasite, it can reduce crop yields by feeding on the roots of crops like maize. Correct identification of this species is crucial as maize is a vital crop in South Africa's Limpopo Province. Therefore, this molecular study was conducted in 2023 at Limpopo University to identify the nematode from South Africa's soils using 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. The nematode was identified as Xiphinema. Afterward, 28S rDNA was amplified using specific primers to identify the nematode at the molecular level. The Nblast analysis based on the large subunit ribosomal DNA showed South African X. oxycaudatum had 99% similarity (MK966417) with the South African population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as X. oxycaudatum in the same clade with highly supported (100) bootstrap values. While 28S rDNA was used to successfully identify this species, further investigation into the phylogeny of X. oxycaudatum will benefit from the addition of other rDNA markers such as ITS rDNA and mitochondrial DNA.

Plant-parasitic nematodes are the main challenge for fruit production in Limpopo Province, South Africa. Besides, the family Tylenchidae are ectoparasite, affecting the yield in a high population. Boleodorus species are not being reported from avocado in South Africa; therefore, its identification is vital to avocado farmers. Hence, molecular study for its accurate identification is needed. This molecular study was conducted in 2022 at the University of Limpopo to identify the nematodes from South African soil associated with crops and trees. First, the recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. Afterward, ITS rDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the ITS rDNA showed 100% similarity with a population of Boleodorus thylactus (MZ099822, MZ099823) from Canada. In addition, phylogenetic analysis using the maximum likelihood method as implemented in mega x software was done. The phylogenetic analysis put the South African populations of B. thylactus together with other B. thylactus with a 100-bootstrap value. In conclusion, this species' diversity needs to be investigated to determine the impact of this nematode on the avocado yield.

Plant-parasitic nematodes are the main challenge for fruit production in Limpopo Province, South Africa. Besides, the family Tylenchidae are ectoparasite, affecting the yield in a high population. Boleodorus species are not being reported from avocado in South Africa; therefore, its identification is vital to avocado farmers. Hence, molecular study for its accurate identification is needed. This molecular study was conducted in 2022 at the University of Limpopo to identify the nematodes from South African soil associated with crops and trees. First, the recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. Afterward, ITS rDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the ITS rDNA showed 100% similarity with a population of Boleodorus thylactus (MZ099822, MZ099823) from Canada. In addition, phylogenetic analysis using the maximum likelihood method as implemented in mega x software was done. The phylogenetic analysis put the South African populations of B. thylactus together with other B. thylactus with a 100-bootstrap value. In conclusion, this species' diversity needs to be investigated to determine the impact of this nematode on the avocado yield.

Predatory nematodes are the main nematodes that live in the soil assisting with the biological control of the plant parasitic nematodes associated with various crops. Mononchus species is a predatory nematode and therefore can feed on the other nematodes that exist in the soil. This species is important due to its critical role in the biocontrol strategy and therefore must be identified correctly. The soil samples were collected from a tomato field in Limpopo Province in South Africa. This molecular study was conducted in 2022 at Limpopo University to identify the nematode species from South Africa's soils using 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. The nematode was identified as Mononchus sp. Afterwards, 28S rDNA was amplified using specific primers to identify the nematode at the molecular level. The Nblast analysis based on the large subunit ribosomal DNA showed South African Mononchus sp. had 99 % similarity (KY750781) with a Mexican population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as Mononchus in the same clade with highly supported (100) bootstrap values. In conclusion, this is the first 28S rDNA of a Mononchus from South Africa. Additionally, though this species was identified using 28S rDNA however, the use of other rDNA markers such as ITS rDNA and 18S rDNA for a better understanding of Mononchus phylogeny is recommended.

During a survey on the biodiversity of plant-parasitic nematodes in Limpopo Province, South Africa, Bitylenchus ventrosignatus was discovered around the rhizosphere of a tomato in Dalmada. The nematodes were extracted using the tray method and then fixed according to available protocols. The morphological characters fit well with the description of B. ventrosignatus. In addition, molecular analysis using 18S and 28S rDNA indicated 99% similarity (MW255611; MW255613) with the Botswana population of B. ventrosignatus. The phylogenetic analysis of 18S and 28S rDNA placed the examined population with other populations of B. ventrosignatus in a group with a posterior probability support value of 1.00. According to published literature, this is the first morphological and molecular characters of 18S and 28S rDNA of B. ventrosignatus from South Africa.

Dorylaimida members are medium to large nematodes that live in the soil and create a balanced environment towards improving yield in various crops. Aporcella species are omnivores and, therefore, can feed on other nematodes around the roots of maize, resulting in better production. This species must be identified correctly because it is a beneficial nematode and can enhance the yield of maize through the microbial balancing of the soil. On the other hand, maize is one of the most important crops in Limpopo Province in South Africa. Therefore, this molecular study was conducted in 2023 at Limpopo University to identify the nematode from South Africa's soils using 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the Chelex method. The nematode was identified as Aporcella simplex (Thorne and Swanger). Afterwards, 28S rDNA was amplified using specific primers to identify the nematode at the molecular level. The Nblast analysis based on the large subunit ribosomal DNA showed that South African A. simplex had 99% similarity (MN262455) with the South African population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as A. simplex in the same clade with highly supported (100) bootstrap values. In conclusion, this species was determined using 28S rDNA; however, other rDNA markers, such as ITS rDNA and mtDNA, are recommended for a better understanding of A. simplex phylogeny.

Solanum melongena is the sixth most important vegetable worldwide. In recent years, eggplant production has been increasing. Therefore, study about plant diseases in this plant is important. One of the most important diseases in eggplant is plant-parasitic nematodes. Therefore, this molecular study was conducted in 2021 at the University of Limpopo to identify the plant-parasitic nematodes identified from South African soil causing yield loss in eggplant. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the Chelex method. Afterward, 28S rDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the large subunit ribosomal DNA showed 99% similarity with a population of Hemicycliophora typica (KF430515) from South Africa. In addition, phylogenetic analysis using the maximum likelihood method as implemented in mega x software was done. The phylogenetic analysis put the South African populations of H. typica together with other H. typica with a 100-bootstrap value. In conclusion, the results showed that 28S could detect the H. typica, and therefore the species is verified by the molecular method. Also, the ecological behavior of the H. typica in terms of the economic impact on the eggplant needs to be investigated.

Plant parasitic nematodes are the main nematodes that live in the soil, causing yield loss for various crops. Pratylenchus species is endoparasite and known as root lesion nematode, therefore, can feed on the roots of the banana, resulting in necrosis and less production. This species is indicated to be highly risky to plants and must be identified correctly, and it is associated with bananas as one of the most important crops in Limpopo Province in South Africa. Therefore, this molecular study was conducted in 2023 at the Limpopo University to identify the Pratylenchus from South Africa's soils using the cox1 region of mtDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the Chelex method. The nematode was identified as Pratylenchus vulnus. Afterwards, cox1 of mtDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the mtDNA showed that South African P. vulnus had 99% similarity (KY424096; KY424097) with Chinese populations. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as P. vulnus in the same clade with highly supported (100) bootstrap values. In conclusion, this species was determined using cox1 of mtDNA; however, other rDNA markers, such as ITS, and rDNA, were recommended for a better understanding of Pratylenchus phylogeny.

Free-living nematodes belong to the family Cephalobidae are bacterivores contribute towards soil health are a good source for the biological and genetic analysis. Zeldia punctata is a free-living bacterivores which distributed across South Africa. This species is an important in the biodiversity of the soil nematode and needs to be identified correctly. Hence, ITS rDNA is a useful tool for identification of Z. punctate. Therefore, this molecular study was conducted in 2018 at the Limpopo University to identify the free-living bacterivores nematodes from South Africa's soils using ITS rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using chelex method. The recovered nematode identified as Zeldia punctata. Afterward, ITS rDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the ITS rDNA showed South African Z. punctata has 96% similarity (DQ146427) with the American population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as Z. punctata in the same clade with highly supported (100) bootstrap values. In conclusion, this species is identified using ITS rDNA properly. However, using other rDNA markers such as 18S and 28S rDNA for a better understanding of Zeldia phylogeny is recommended.

Dorylaim nematodes are the main nematodes that live in the soil. Dorylaim nematode is a predator which uses other nematodes as their food and hence, a possibility to against plant-parasitic nematode. Therefore, this molecular study was conducted in 2017 at the North West University to identify the soil nematodes from South Africa’s using 18S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using the chelex method. The nematode was identified as Discolaimium. Afterward, 18S rDNA was amplified using specific primers to identify thenematode. The Nblast analysis based on the small subunit ribosomal DNA showed South African Discolaimium has 97% similarity (MG921261) with Chinese population of Discolaimium. Phylogenetic analysis using maximum likelihood placed this species with nthose molecularly identified as Discolaimium in the same clade with highly supported (100) bootstrap values. Inconclusion, this species is identified using 18S rDNA properly. However, using other DNA markers for a better understanding of Discolaimium phylogeny is recommended.

South Africa is a significant producer and exporter of avocados in the world. Xylosandrus crassiusculushas was found on mainland Africa for many years but the present study represents the first record of bark beetle in South Africa in Limpopo Province. Its presence infesting important agronomic tree crops such as avocado suggests that it requires further study. Therefore, this molecular study was conducted in 2022 at the University of Limpopo to identify the bark beetle in the South African avocado orchard. The recovered bark beetle was isolated from the bark of avocado in Magoebaskloof region in Limpopo Province. Then its DNA was extracted using the Chelex method, and the phylogenetic position of the beetle was studied using 28S rDNA. The Nblast analysis based on the large subunit ribosomal DNA showed 99% similarity with a population of Xylosandrus crassiusculus from South Africa (MT229960), USA (GU808593), and Taiwan (MT120970). In addition, phylogenetic analysis using the maximum likelihood method as implemented in mega x software was done. The phylogenetic analysis put the South African populations of X. crassiusculus together with other X. crassiusculus with a 100-bootstrap value. In conclusion, the results showed that 28S could detect the X. crassiusculus, and was verified by the molecular method.

South Africa is a significant producer and exporter of avocados in the world. Xylosandrus crassiusculushas was found on mainland Africa for many years but the present study represents the first record of bark beetle in South Africa in Limpopo Province. Its presence infesting important agronomic tree crops such as avocado suggests that it requires further study. Therefore, this molecular study was conducted in 2022 at the University of Limpopo to identify the bark beetle in the South African avocado orchard. The recovered bark beetle was isolated from the bark of avocado in Magoebaskloof region in Limpopo Province. Then its DNA was extracted using the Chelex method, and the phylogenetic position of the beetle was studied using 28S rDNA. The Nblast analysis based on the large subunit ribosomal DNA showed 99% similarity with a population of Xylosandrus crassiusculus from South Africa (MT229960), USA (GU808593), and Taiwan (MT120970). In addition, phylogenetic analysis using the maximum likelihood method as implemented in mega x software was done. The phylogenetic analysis put the South African populations of X. crassiusculus together with other X. crassiusculus with a 100-bootstrap value. In conclusion, the results showed that 28S could detect the X. crassiusculus, and was verified by the molecular method.

Plant-parasitic nematodes are some of the most important plant pathogens in tomato farms. Tomato is an acritical and high-demand vegetable in the world. The plant-parasitic nematodes are highly adapted and can cause severe damage to tomato farms. Therefore, understanding the population of nematodes on the tomato field assists the farmer in managing them and having better yields. This study was conducted to identify nematode species from the soil and root samples during a survey of plant-parasitic nematodes in four tomato farms in 2021. The samples were collected across the farms in Limpopo province, South Africa. Analyzing the soil and identifying the nematodes has been done at the Aquaculture Research Unit, University of Limpopo. Seven nematode species were identified from the soil and root samples out of the 40 soil samples collected. The nematodes encountered were Meloidogyne (700), Pratylenchus (430), Xiphinema (380), Helicotylenchus (260), Ditylenchus (180), Rotylenchus (110), Tylenchorhynchus (90). The CCA results indicated the contribution of PPN species and soil variables in tomato farms to the analysis indicated that Meloidogyne and Rotylenchus were dominant in substrates characterized by soil structure (Clay, Silt%), and high-level of Ca (%), Carbon (%), and K (%) found in Polokwane and Tzaneen tomato farms. At the same time, Helicotylenchus, Pratylenchus, and Xiphinema were dominant in substrates characterized by sand (%), Na (%), and Mg (%) found in Giyani and Louis Trichardt tomato farms. In conclusion, soil factors can directly affect soil biology. In this study, the results showed unsustainable soil factor was the reason for the high plant-parasitic nematode population in the tomato field.

Free-living bacterivores nematodes are the main nematodes that live in the soil. Free-living bacteria are essential for the soil food web. The genus Diploscapter is distributed in the soil with several species. Hence, the identification based on the molecular rDNA, specifically 28S rDNA is necessary for D. coronatus. Therefore, this molecular study was conducted in 2018 at the Limpopo University to identify the freeliving bacterivores nematodes from South Africa's soils using 28S rDNA marker. The recovered nematode was extracted using the tray method, and then its DNA was extracted using chelex method. Afterward, 28S rDNA was amplified using specific primers to identify the nematode. The Nblast analysis based on the large subunit ribosomal DNA showed South African D. coronatus has 97% similarity (MK541668) with Germany's population. Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as D. coronatus in the same clade with highly supported (100) bootstrap values. In conclusion, this species is identified using 28S rDNA properly. However, using other rDNA markers such as 18S rDNA and ITS rDNA for a better understanding of Diploscapter phylogeny is recommended.