Identification and pathogenicity of Pratylenchus scribneri on tomato in Sichuan Province of People's Republic of China

Root-lesion nematodes (Pratylenchus spp.) are a group of economically important pathogens that have caused serious economic losses in many crops. In 2019, root-lesion nematodes were recovered from tomato (Solanum lycopersicum) root samples collected from Sichuan Province, People's Republic of China (PRC). Extracted nematodes were disinfected, and one individual female was cultured on a carrot disc for propagation at 25 °C by parthenogenesis and designated the SC isolate. Afterwards, the isolate was identified on the basis of morphometric and molecular markers. Both morphometric characters and molecular analysis of the internal transcribed spacer region gene (ITS) of ribosomal DNA, the D2-D3 expansion region of the 28S rDNA gene and the mitochondrial cytochrome oxidase I (mtDNA-COI) gene revealed that the species of root-lesion nematode was Pratylenchus scribneri. The Bayesian tree inferred from the ITS rDNA, 28S rDNA and mtDNA-COI gene sequences also showed that this isolate formed a highly supported clade with other P. scribneri isolates. The pathogenicity of the root-lesion nematode SC isolate on tomato was assessed, showing that tomato was a suitable host for P. scribneri. To the best of our knowledge, this is the first report of P. scribneri on tomato in Sichuan Province, PRC. These are also the first molecular data obtained from P. scribneri on tomato in the PRC, and the pathogenicity of P. scribneri to tomato was studied for the first time. This study provides scientific data for the detection, identification and control of tomato root-lesion nematode disease.

First Report of the Apple Root-Knot Nematode, Meloidogyne mali, on Maple Trees in Republic of Korea

Meloidogyne mali was originally described in Japan on roots of an apple rootstock (Malus prunifolia) (Itoh et al. 1969) and found on elm trees in Italy, Netherlands, Belgium, France and United Kingdom, and euonymus in the USA (EPPO 2018; Prior et al. 2019). In Italy, the nematode was initially described as a new species, Meloidogyne ulmi, but was later synonymized with M. mali (Ahmad et al., 2013). During the study of Meloidogyne species in Republic of Korea, galled roots were found on Acer palmatum collected in Naejangsan National Park, Republic of Korea located at 35°29'29.1"N, 126°55'42.7"E, altitude 147.8 m. Morphologically, the perineal patterns of the females was very similar to M. mali due to rounded dorsal arch and smooth, finely-spaced, indistinct striae. Lateral field shallow, narrow, and faint. Phasmids large, very distinct. Head region of second–stage juveniles flattened anteriorly to hemispherical, slightly set-off from body, without annulations, low head cap. Stylet slender, sharply pointed cone, cylindrical shaft with rounded knob sloping posteriorly. Tail conoid with irregular, and rounded end. Rectum undilated. Several micrographs were made from 25 J2s and females for mean, standard deviation and range. J2s were measured with a body length: 408.2 ± 25.1 (366-449) µm, maximum body width: 15.9 ± 1.0 (14.1-17.9) µm, stylet length: 14.1 ± 0.5 (13.1-15.3) µm, hyaline tail terminus: 10.0 ± 0.9 (8.3-11.0) µm and tail length: 31.7 ± 3.0 (26.0-36.1) µm. Females (n=25) were characterized by a body length: 656.7 ± 102.7 (516-947) µm, a stylet length: 16.4 ± 2.2 (13.9-19.0) µm, a vulval slit length: 22.2 ± 1.8 (19.8-25.7) µm, and a vulva-anal distance: 20.2 ± 2.4 (17.1-25.4) µm. Morphological measurements and configuration of perineal patterns (Fig. 1S) were comparable to M. mali (Itoh et al. 1969; Ahmed et al. 2013; Gu et al. 2020). To confirm pathogenicity, a modified version of Koch’s postulates was conducted in the greenhouse by inoculating 300 eggs from a single egg mass onto each of three, two-year-old A. palmatum plants, grown in sterilized sandy soil. After about one year, symptoms developed on the maple tree roots, with numerous galls containing females and egg masses by visual inspection. In addition, PCR was performed for the 28S rDNA D2-D3 segment and ITS region using the primers D2A, D3B, TW81 and AB28. The resulting sequences (MW522548, MW522549, MW523004 and MW523005) were at least 99% identical to other 28S rDNA D2-D3 segment and ITS region sequences on Genbank (MT406757 and JX978229). The molecular phylogenetic relationships of this species strongly supports M. mali (Fig. 2S). To the best of our knowledge, this is the first report of M. mali in Republic of Korea. The host range of M. mali includes many species which are of economic importance in fruit trees (e.g. apple, chestnut, fig, mulberry), forestry trees (e.g. elm, maple, oak, Yew), and vegetable crops (e.g. cabbage, carrot, cucumber, eggplant, soybean, watermelon). The potential danger to these economically important plants caused M. mali to be added the EPPO Alert List and also the Quarantine List of the Korean Animal and Plant Quarantine Agency. Additionally, in our survey around the Naejangsan National Park, M. mali was not found on other economically important host crops, such as grapes. Although this nematode was not detected other crops, it requires regular monitoring because it poses a serious threat to the future production of these crops.

Three new genera and new species of hystrignathid nematodes (Nematoda: Thelastomatoidea) from passalid beetles (Insecta: Passalidae) from Yunnan Province, China with phylogenetic analysis of Hystrignathidae

Three new genera and three new species of hystrignathid nematodes were collected from the hindgut of passalid beetles in the Yunnan Province, China. Huntia morffei gen. n. et sp. n. from Ceracupes fronticornis (Westwood) differs from related genera in the shape of the stoma, in the cephalic structure, and in the lack of annulation in the cervical region. Parakongonema sinica gen. n. et sp. n. from Aceraius grandis (Burmeister) and C. fronticornis can be easily distinguished from related genera in having the oral opening surrounded by a cuticular ring, the ring being surrounded by a cuticular flap, in the shape of the oesophagus, and in the cephalic structure. Parahystrignathus tongbiguanensis gen. n. et sp. n. from C. fronticornis and A. grandis differs from related genera by having the cervical region armed with alternating rows of spines, with 16 spines in the first row, and by lacking the first cephalic annule. In addition, the 18S and 28S rDNA partial sequences of three new species were obtained. The phylogeny of Hystrignathidae was inferred using partial sequences of the 28S rDNA and revealed patterns that suggest that the shape of the parasite digestive tract may reflect the evolutionary relationships of hystrignathid nematodes.

Notes on the genus Dendrocerus Ratzeburg (Hymenoptera, Megaspilidae) from China, with description of two new species

Species of the genus Dendrocerus Ratzeburg, 1852 (Hymenoptera: Megaspilidae) from China were studied. Six species are recorded, of which two known species, D. carpenteri (Curtis, 1829) and D. laticeps (Hedicke, 1929) are re-described; and two species are described as new to science, D. anisodontus Wang, Chen and Mikó sp. nov. and D. bellus Wang, Chen and Mikó sp. nov.. Sequences of the 28S rDNA were generated to associate both sexes of the same species.

Hyperparasitism on Plasmopara viticola by Simplicillium lanosoniveum

A previously unknown association between Plasmopara viticola, the causal pathogen of grape downy mildew, and the mycoparasite strain F2 was described in this paper. F2 could be consistently isolated from the mildew of diseased spots on grape leaves of Kyoho (Vitis labrusca × V. vinifera cv. Kyoho) infected with P. viticola, but neither from the surfaces of healthy grape leaves nor within lesions of other diseases. It could be observed that strain F2 was capable of coiling around sporangiophores and sporangia of P. viticola under microscope, causing hyphae deformation, decreasing the pathogen growth, and reducing the number of sporangia. This fungal strain was identified as Simplicillium lanosoniveum on the basis of morphological characterizations and 28S rDNA sequencing. To our knowledge, this is the first report of S. lanosoniveum with hyperparasitic characteristics on P. viticola, and the hyperparasite has potential application in the control of grape downy mildew.

PHYLOGENETIC ANALYSIS AND SPECIES IDENTIFICATION OF 11 GORGONIAN CORALS (OCTOCORALLIA: ALCYONACEA) IN THE NORTH CENTRAL COAST OF VIETNAM BASED ON MSH1MTDNA AND 28S RDNA MARKERS

Vietnam contains diverse marine ecosystems with the high biodiversity of marine organisms, including gorgonian corals of Alcyonacea order. In order to support traditional classification of these corals, in this study mitochondrial barcoding markers msh1 and nuclear 28S rDNA were developed for analysis of 11 specimens collected in 2015 and 2016 from different islands and bays along the North Central coast of Vietnam. Phylogenetic analyses based on msh1 and 28S sequence polymorphism showed that all specimens belonged to Anthozoa class, Octocorallia sub-class and Alcyonacea order. At lower taxa levels, they were divided into 4 sub-orders, 7 families and 7 genera according to 7 distinct clades with bootstrap values from 99-100%.The identifications of 7 out of 11 specimens including Sinularia brassica (2 specimens)and Sinularialeptoclados, Dichotellagemmacea, Annella reticulata, S. conferta and S. nanolobata were in concordance between morphological and molecular methods. The other 4 specimens were only identified at genus levels of Astrogorgia sp., Melithaea sp. Scleronephthya sp. and Muricella sp. by either msh1-morphology or msh1-28S markers. These results highlight the importance of molecular markers to elucidate patterns of biodiversity and species identification of soft coral.

Molecular Characterisation and Phylogenetic Analysis of Dermatophytic Fungi Isolated from Tinea Capitis in Northwest Nigeria Using Sequence of the 28S rRNA

The detection and identification of fungal DNA from clinical samples is one of the fundamental approaches in biomedicine. The incidence, distribution, and control of dermatophytes has progress significantly and the use of phylogenetic species concepts based on rRNA regions have enhanced the taxonomy of dermatophyte species; however, the use of 28S rDNA genes has certain limitations. This gene has been used in dermatophyte taxonomy with limited enumeration; we appraised the sequence disparity within and among groups of the species, the gene ranking in identification, phylogenetic analysis, and taxonomy of 32 strains of eight dermatophyte species. In this study, a set of primers was adopted to amplify the target followed by a partial sequencing of the rDNA. The utilization of a pairwise nucleotide differentiation, an affinity was observed among eight dermatophyte species, with disparity among species ranging from 0 to 197 base pair (bp). Intra-species bp differences were found within strains of Trichophyton eriotrephon, Trichophyton bullosum, Trichophyton simii (Trichophyton genus), Microsporum audouinii, and Trichophyton tonsurans (Microsporum and Trichophyton genus, respectively); however, only some strains of Trichophyton eriotrephon were found to be invariant having three genotypes. Trichophyton tonsurans exhibited most intra-species variability. The characterization and construction of a phylogenetic tree of 28S rDNA gene on dermatophyte species provide a bedrock of an additional finding of connections between species. However, 28S rRNA capture provides a novel method of effective and sensitive detection of dermatophytes lodged in human skin scale. We report for the first time the emergence of T. eriotrephon, T. bullosum, T. simii, T. benhamiae, and Ctenomyces serratus dermatophytes from Tinea capitis in Nigeria.