scholarly journals Pratylenchus vovlasi sp. Nov. (Nematoda: Pratylenchidae) on Raspberries in North Italy with a Morphometrical and Molecular Characterization

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1068
Author(s):  
Alberto Troccoli ◽  
Elena Fanelli ◽  
Pablo Castillo ◽  
Gracia Liébanas ◽  
Alba Cotroneo ◽  
...  
Keyword(s):  
Its Region ◽  
Nematode Species ◽  
Integrative Taxonomy ◽  
Integrative Approach ◽  
Parasitic Nematodes ◽  
Rrna Gene ◽  
28S Rrna ◽  
Root Lesion Nematode ◽  
Cyst Nematodes ◽  
Lesion Nematode

Root-lesion nematode species rank third only to root-knot and cyst nematodes as having the greatest economic impact on crops worldwide. A survey of plant-parasitic nematodes associated with decaying raspberries (Rubus sp.) in northern Italy revealed that root-lesion nematodes were the most frequently occurring species among other phytonematodes. Several Pratylenchus species have been associated with Rubus sp. in Canada (Quebec, British Columbia) and USA (North Carolina, Maryland, New Jersey) including P. penetrans and P. crenatus. In the roots and rhizosphere of symptomatic raspberries, nematodes of two Pratylenchus spp. were detected. Detailed morphometrics of the two root-lesion nematode isolates were consistent with Pratylenchus crenatus and with an undescribed Pratylenchus species. The extracted nematodes were observed and measured as live and fixed materials and subsequently identified by integrative taxonomy (morphometrically and molecularly). The latter species is described herein as Pratylenchus vovlasi sp. nov., resulting morphometrically closest to P. mediterraneus and phylogenetically to P. pratensis. The molecular identification of Pratylenchus vovlasi sp. nov. was carried out by sequencing the ITS region, D2-D3 expansion domains of the 28S rRNA gene and a partial region of the nuclear hsp90 gene. ITS-RFLP and sequence analyses revealed that Pratylenchus vovlasi sp. nov. had species-specific restriction profiles with no corresponding sequences present in the database. The phylogenetic relationships with ITS and D2-D3 sequences placed the Pratylenchus vovlasi sp. nov. in a clade with P. pratensis and P. pseudopratensis. This research confirms the occurrence of cryptic biodiversity within the genus Pratylenchus as well as the need for an integrative approach to the identification of Pratylenchus species.

scholarly journals Occurrence and molecular characterization of cyst nematode species (Globodera spp.) associated with potato crops in Colombia

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0241256
Author(s):  
Daniela Vallejo ◽  
Diego A. Rojas ◽  
John A. Martinez ◽  
Sergio Marchant ◽  
Claudia M. Holguin ◽  
...  
Keyword(s):  
Management Strategies ◽  
Nematode Species ◽  
Globodera Pallida ◽  
Rrna Gene ◽  
Potato Cyst Nematodes ◽  
28S Rrna ◽  
Cyst Nematodes ◽  
Nucleotide Substitutions ◽  
Internal Transcribed Spacer Region ◽  
The Status

Potato cyst nematodes (PCN) from the genus Globodera spp. cause major losses in the potato (Solanum tuberosum) industry worldwide. Despite their importance, at present little is known about the status of this plant pathogen in cultivated potatoes in Colombia. In this study, a total of 589 samples collected from 75 geographic localities in nine potato producing regions of Colombia (Cundinamarca, Boyacá, Antioquia, Nariño, Santander, Norte de Santander, Tolima, Caldas and Cauca) were assayed for the presence of potato cyst nematodes. Fifty-seven percent of samples tested positive for PCN. Based on phylogenetic analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of the rRNA gene and D2-D3 expansion segments of the 28S rRNA gene, all populations but one were identified as Globodera pallida. Sequences of G. pallida from Colombia formed a monophyletic group closely related to Peruvian populations, with the lowest average number of nucleotide substitutions per site (Dxy = 0.002) and net nucleotide substitutions per site (Da = 0.001), when compared to G. pallida populations from Europe, South and North America. A single sample formed a well-supported subclade along with G. rostochiensis and G. tabacum from Japan, USA and Argentina. To our knowledge this is the first comprehensive survey of Globodera populations from Colombia that includes genetic data. Our findings on species diversity and phylogenetic relationships of Globodera populations from Colombia may help elucidate the status and distribution of Globodera species, and lead to the development of accurate management strategies for the potato cyst nematodes.

scholarly journals Detection and Discrimination of Pratylenchus neglectus and P. thornei in DNA Extracts from Soil

Plant Disease ◽  
2008 ◽  
Vol 92 (11) ◽  
pp. 1480-1487 ◽  
Author(s):  
Guiping Yan ◽  
Richard W. Smiley ◽  
Patricia A. Okubara ◽  
Andrea Skantar ◽  
Sandra A. Easley ◽  
...  
Keyword(s):  
Nematode Species ◽  
Wheat Root ◽  
Fungal Species ◽  
Parasitic Nematodes ◽  
Rrna Gene ◽  
28S Rrna ◽  
Pratylenchus Neglectus ◽  
Pcr Products ◽  
Species Specific ◽  
Plant Parasitic

A species-specific polymerase chain reaction (PCR) method was developed to detect and identify the root-lesion nematodes Pratylenchus neglectus and P. thornei from soil. A primer set was designed from Pratylenchus 28S rRNA gene sequences of the D3 expansion domain. Primer specificity was confirmed with 23 isolates of 15 nematode species and other plant-parasitic and non-plant-parasitic nematodes typically present in the soil communities, and with six fungal species commonly associated with wheat root rot. DNA obtained using a commercially available kit and a method developed in our laboratory gave comparable amplification. PCR conditions were optimized and the two species were differentiated by PCR products of 144 bp for P. neglectus and 288 bp for P. thornei. With this assay, we detected a single juvenile in 1 g of sterile, inoculated soil. Examination of 30 field soil samples revealed that this method was applicable to a range of soils naturally infested with these two pathogens in Oregon. This PCR-based method is rapid, efficient, and reliable, does not require expertise in nematode taxonomy and morphology, and could be used as a rapid diagnostic tool for commercial and research applications for disease forecasting and management.

scholarly journals Molecular and morphological characterisation of Longidorus polyae sp. n. and L. pisi Edward, Misra & Singh, 1964 (Dorylaimida, Longidoridae) from Bulgaria

ZooKeys ◽  
2019 ◽  
Vol 830 ◽  
pp. 75-98 ◽  
Author(s):  
Stela S. Lazarova ◽  
Milka Elshishka ◽  
Georgi Radoslavov ◽  
Lydmila Lozanova ◽  
Peter Hristov ◽  
...  
Keyword(s):  
New Species ◽  
Body Length ◽  
Nematode Species ◽  
Molecular Data ◽  
18S Rrna Gene ◽  
The Body ◽  
Integrative Approach ◽  
Rrna Gene ◽  
28S Rrna ◽  
Stage Juvenile

Longidoruspolyaesp. n., a bisexual nematode species found in the rhizosphere of pear tree (Pyruscommunis L.), is described and characterised using an integrative approach. The new species has a female body length of 6.8–9.1 mm; a comparatively long odontostyle (114.0–127.5 μm); a narrow lip region (14.0–15.5 μm), anteriorly flattened and almost continuous with the body profile; pocket-like amphidial pouches long, deeply bilobed, and slightly asymmetrical, a guide ring at 37–42 μm from the anterior end; normal arrangement of pharyngeal glands; and a short bluntly rounded to hemispherical tail. Four juvenile stages identified: the first stage with a digitate tail, and the second and subsequent stages with a bluntly rounded tail. Males have one adcloacal pair and a row of 10 or 11 single ventromedian supplements; spicules 71.0–74.5 μm long. Based on morphometric data, the new species belongs to a group of species spread over Europe (L.arthensis, L.silvae, L.uroshis,), Iran (L.kheirii), and Syria (L.pauli), which share common characters such as amphidial fovea, lip region and tail shapes, similar odontostyle and body length, and similar first-stage juvenile tail shape. Codes for identifying the new species are A5, B2, C34, D3, E3, F45, G12, H1, I2, J1, K7. The phylogenetic analysis based on D2-D3 expansion domains of the rRNA gene revealed that the new species has the closest relationships with L.athesinus from Italy and three unidentified Longidorus spp. from USA (Longidorus sp. 1, Longidorus sp. 2, and Longidorus sp. 6). New morphometric and molecular data (18S rRNA gene, ITS1-5.8S-ITS2 regions and D2-D3 28S rRNA gene sequences) for three populations of L.pisi from Bulgaria were obtained and variations between populations are discussed.

Benzoxazinoids selectively affect maize root-associated nematode taxa

2021 ◽  
Author(s):  
Md Maniruzzaman Sikder ◽  
Mette Vestergård ◽  
Tina Kyndt ◽  
Inge S Fomsgaard ◽  
Enoch Narh Kudjordjie ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Plant Defence ◽  
Plant Secondary Metabolites ◽  
Nematode Species ◽  
Nematode Community ◽  
Maize Root ◽  
Parasitic Nematodes ◽  
Root Lesion Nematode ◽  
Nematode Communities ◽  
Lesion Nematode

Abstract Although the effects of plant secondary metabolites on plant defence have been studied for decades, the exact roles of secondary metabolites in shaping plant-associated microbial and nematode communities remain elusive. We evaluated the effects of benzoxazinoids, a group of secondary metabolites present in several cereals, on root-associated nematodes. We employed 18S rRNA metabarcoding to compare maize root-associated nematode communities in a bx1 knockout maize line impaired in benzoxazinoid synthesis and in its parental wild type. Both genotype and plant age affected the composition of the nematode community in the roots, and the effects of benzoxazinoids on nematode communities were stronger in the roots than in the rhizosphere. Differential abundance analysis and quantitative PCR showed that the root lesion nematode Pratylenchus neglectus was enriched in the bx1 mutant line, while another root lesion nematode, Pratylenchus crenatus, was reduced. Correlation analysis showed that benzoxazinoid concentrations in maize roots mostly correlated negatively with the relative abundance of nematode sequence reads. However, positive correlations between benzoxazinoids and nematode taxa, including several plant-parasitic nematodes, were also identified. Our detailed nematode community analysis suggests differential and selective effects of benzoxazinoids on soil nematodes depending on both the nematode species and the benzoxazinoid compound.

scholarly journals Discovery of Root-Lesion Nematode (Pratylenchus scribneri) on Corn in Hainan Province of China

Plant Disease ◽  
2021 ◽  
Author(s):  
Yanhui Xia ◽  
Jing Li ◽  
Penghui Hao ◽  
Ke Wang ◽  
Bin Lei ◽  
...  
Keyword(s):  
Its Sequences ◽  
Rrna Gene ◽  
Hainan Province ◽  
28S Rrna ◽  
Root Lesion Nematode ◽  
28S Rrna Gene ◽  
Mtdna Coi ◽  
Lesion Nematode ◽  
Corn Plants ◽  
Pratylenchus Scribneri

Corn (Zea mays L.) is a very important cereal crop and serves as food, feed, and industrial material (Liu et al. 2016). The root-lesion nematode (RLN) is considered one of the most important plant-parasitic nematodes and can cause economic losses in agriculture worldwide (Jones et al. 2013). In January 2020, five samples were collected from a corn field in Lingshui Lizu Autonomous County, Hainan Province, China. The collected corn plants (cv. Denghai 685) were growing poorly and roots showed distinct lesions and rot. Corn fields with symptoms of stunted plants, and brown lesions on roots were widespread. This corn disease was severe in Lingshui Lizu Autonomous County. RLN were extracted from soil samples by the modified Baermann funnel (Hooper et al. 2005). All the samples contained RLN ranging from 9 to 82 (average 39) RLN per 100 cm3 of soil and 113 to 257 (average 194) RLN per 5 g roots. The extracted RLN were sterilized and cultured on carrot disks at 25°C for 90 days. Afterwards, seeds of corn (cv. Denghai 685) were sown in pots containing 1.8 liters of sterilized soil. Eight plants, one per pot, were infested with 1,000 RLN, eight pots of noninfested corn plants were used as controls, and plants were kept in a greenhouse at 25°C. At 75 days after inoculation, symptoms were like those initially observed in corn fields, whereas no symptoms were observed in the control plants. Nematodes in the soil and roots were extracted using the same method as previously described (Hooper et al. 2005). The average number of RLN per pot was approximately 4,250 in soil and 820 in roots, the reproduction factor (final number of nematodes/initial number of nematodes) was 5.07, no RLN were found in the control. The experiment was conducted twice. The morphological and molecular studies of RLN were examined to confirm species identification. The main morphological measurements of adult females (n = 15) included body length = 526.0 μm ± 17.1 (standard error) (range = 498.0 to 560.5 μm), stylet = 16.0 μm ± 0.3 (15.5 to 16.5 μm), tail length = 29.0 μm ± 1.5 (26.5 to 31.0 μm), a = 23.6 ± 0.6 (22.6 to 24.4), b = 5.6 ± 0.3 (5.2 to 6.0), c = 18.3 ± 0.9 (16.4 to 19.7), V = 78.2% ± 0.6 (77.4 to 79.2%), lip region with two annules. No males were found in the samples. This population was identified as Pratylenchus scribneri, based on the morphological characters (Castillo and Vovlas, 2007). DNA was isolated from individual nematodes followed by proteinase K-based lysis (Wang et al. 2011). The D2/D3 expansion region of the 28S rRNA gene, rDNA-internal transcribed spacer (ITS) region, and mitochondrial cytochrome oxidase I (mtDNA-COI) gene were amplified with primers D2A/-D3B (De Ley et al. 1999), TW81/ AB28 (Vovlas et al. 2011) and JB3/ JB5 (Liu et al. 2018), respectively. The PCR products were purified and ligated into pJET 1.2/blunt cloning vectors and transformed to Escherichia coli strain DH5α, and then sequenced. The obtained 28S rRNA gene D2/D3 region sequences (785bp), ITS sequences (886 bp) and mtDNA-COI (447bp) in this study were submitted to GenBank. The D2/D3 region of the 28S rRNA sequences of the RLN collected in Lingshui (GenBank accession no. MZ701843) showed 99.75% identity with P. scribneri sequences available in the GenBank (KX842628 and KX842625). The ITS sequences of the RLN collected in this study (MZ701842) showed the highest identity of 97.06% with P. scribneri sequences available in the GenBank (KX842626). The mtDNA-COI sequences of the RLN collected in this study (OK040228) showed 100% identity with P. scribneri (MN366409). Both morphological and molecular data confirmed the identity of P. scribneri. P. scribneri has been reported on corn in Inner Mongolia, Hebei, Shanxi, Shandong, Henan, Jiangsu, and Liaoning provinces of China (Li et al. 2019). As far as we know, this is the first report of P. scribneri on corn in Hainan Province, China. Since the RLN can cause considerable damage to corn, strategic measures should be taken to prevent the spread of P. scribneri to other regions in China.

Pratylenchus speijeri n. sp. (Nematoda: Pratylenchidae), a new root-lesion nematode pest of plantain in West Africa

Nematology ◽  
2012 ◽  
Vol 14 (8) ◽  
pp. 987-1004 ◽  
Author(s):  
Francesca De Luca ◽  
Alberto Troccoli ◽  
Larry W. Duncan ◽  
Sergei A. Subbotin ◽  
Lieven Waeyenberge ◽  
...  
Keyword(s):  
New Species ◽  
West Africa ◽  
Species Complex ◽  
Rrna Gene ◽  
28S Rrna ◽  
New Taxon ◽  
Root Lesion Nematode ◽  
Specific Primers ◽  
Lesion Nematode ◽  
Species Specific

A new root-lesion nematode, particularly pathogenic to Musa spp. and causing important plantain losses in Ghana, is described and named Pratylenchus speijeri n. sp. The cryptic status of this species within the P. coffeae species complex has been assessed and confirmed in this study. An extensive comparison of the morphological and molecular characteristics of this new species with those of P. coffeae and other related amphimictic species did not result in an unambiguous separation of this species from P. coffeae because only a few morphological features of diagnostic value were found. Sequence and phylogenetic analyses of the D2-D3 expansion segments of the 28S rRNA gene, the ITS rRNA gene and a portion of the hsp90 gene of P. speijeri n. sp. and P. coffeae species complex populations from different sources generated majority consensus BI trees with three major clades: P. speijeri n. sp. from Musa spp. roots in Ghana; unidentified or putative new Pratylenchus sp. C1 from Colocasia esculenta roots in Japan and P. coffeae with non-homogeneous relationships from different hosts and distant geographical areas. These results confirmed the validity of P. speijeri n. sp. as a new taxon and indicated that P. coffeae populations from Colocasia in Japan also need to be considered as a new species. Sequence differences in the ITS were used to design group- and species-specific primers to detect P. speijeri n. sp. and other species of P. coffeae species complex. The use of these species-specific primers for the separation of P. speijeri n. sp., Pratylenchus sp. C1 and P. coffeae has important practical application in breeding programmes for agriculture in West Africa.

scholarly journals Occurrence of Pratylenchus coffeae Causing Root Rot of Soybean in Shandong Province of China

Plant Disease ◽  
2020 ◽  
Author(s):  
Ke Wang ◽  
Yankun Liu ◽  
PengHui Hao ◽  
Yanhui Xia ◽  
Bingjian SUN ◽  
...  
Keyword(s):  
Body Length ◽  
Tail Length ◽  
Its Region ◽  
Shandong Province ◽  
28S Rrna ◽  
Root Lesion Nematode ◽  
Pratylenchus Coffeae ◽  
Lesion Nematodes ◽  
Lesion Nematode ◽  
Root Lesion Nematodes

Soybean (Glycine max L.) is a very important commercial crop in China (Li et al. 2019). Pratylenchus coffeae (Zimmermann, 1898) Filipjev & Schuurmans Stekhoven, 1941, is one of the most important root-lesion nematodes that invade the roots of many crops. In August 2018, five root and soil samples were collected in a soybean field, near Xipan village in Linshu county of Linyi City, Shandong Province, China (Fig. S1), to investigate the occurrence of root-lesion nematodes. The collected plants (cv. Lindou No.10) were growing poorly and the roots showed distinct brown lesions (Fig. S2). Pratylenchus spp. were extracted using the modified Baermann funnel method for 2 days (Hooper et al. 2005). On average, 395 root-lesion nematodes per kg of soil and 36 root-lesion nematodes per gram of fresh roots were extracted. The extracted root-lesion nematodes were disinfected with 0.3% streptomycin sulfate and cultured on carrot disks for propagation at 25°C. The species identification was based on morphological and molecular criteria. Key morphological features were determined for females and males. Measurements of females (n = 16) included body length = 561.0 μm ± 37.6 (standard deviation) (520.5 to 654.0 μm), tail length = 30.0 μm ± 1.9 (27.0 to 33.5 μm), stylet = 16.0 μm ± 0.6 (15.0 to 17.5 μm), a = 28.2 ± 2.3 (23.7 to 31.5), b = 6.4 ± 0.5 (5.7 to 7.3), c = 18.7 ± 1.8 (15.7 to 23.8), and V = 80.8% ± 2.1 (76.5 to 83.8%). Measurements of males (n = 16): body length = 511.0 μm ± 28.1 (range= 475.5 to 566.0 μm), tail length = 26.0 μm ± 1.3 (23.5 to 28.5 μm), stylet = 15.0 μm ± 0.5 (14.5 to 16.0 μm), spicule length = 17.0 μm ± 0.9 (16.0 to 18.5 μm), a = 30.8 ± 1.5 (28.0 to 33.2), b = 6.1 ±0.4 (5.6 to 6.9), and c = 19.8 ± 1.3 (18.1 to 22.2) (Fig. S3). All the morphological features of this population matched the description of P. coffeae (Castillo and Vovlas, 2007). DNA was extracted from an individual female as described previously (Wang et al. 2011). The rDNA-internal transcribed spacer (ITS) region and the D2/D3 region of the 28S rRNA gene were amplified by primers 18S/26S (Vrain et al. 1992) and D2A/D3B (De Ley et al. 1999), respectively. The PCR products were purified and sequenced. The obtained sequences of the ITS region (1,253 bp) and the D2/D3 region of 28S rRNA (781 bp) were deposited in GenBank. The ITS sequences of the root-lesion nematode obtained in this study (GenBank Accession no. MT879294) exhibited 99% identity with several P. coffeae sequences available in the GenBank (e.g., KR106219, MT586756, KY424205, and MN749379), and the obtained D2/D3 region sequence (MT879295) exhibited 100% identity with several P. coffeae sequences (e.g., MT586754, MN750755, MK829009, and MH730447). Both morphological and molecular data confirmed the presence of P. coffeae. To confirm reproduction on soybean, the obtained root-lesion nematode population was used in a greenhouse (25°C) assay to fulfill modified Koch’s postulates. About 20 days after sowing, eight pots, each with one soybean plant (Lindou No.10) were inoculated with 1000 P. coffeae. The inoculated plants were kept in 1.5 L pots containing 1.2 L sterilized soil. Eight pots of uninoculated soybeans were used as the control. Ten weeks later, the inoculated roots were washed and brown lesions were observed. The number of nematodes/pot was approximately 7360 in soil and 796 in roots, and the reproduction factor was 8.16. Root-lesion nematodes and symptoms were not observed in control groups. P. coffeae has only been reported on soybean in Zhejiang (Wei et al. 2013) and Henan Province (Li et al. 2019) of China. To our knowledge, this is the first report of P. coffeae infecting soybean in Shandong Province, China. Since the root-lesion nematode can cause considerable damage to soybean, care should be taken to prevent the spread of P. coffeae to other regions in China.

Integrative taxonomy of the willow cyst nematode, Heterodera salixophila Kirjanova, 1969, a new record of the Humuli group from Iran

Nematology ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 57-67
Author(s):  
Younes Rezaee Danesh ◽  
Abbas Mokaram Hesar ◽  
Reza Ghaderi
Keyword(s):  
Principal Component ◽  
Hierarchical Cluster ◽  
Integrative Taxonomy ◽  
Cyst Nematode ◽  
Parasitic Nematodes ◽  
28S Rrna ◽  
Cyst Nematodes ◽  
Morphometric Characters ◽  
Molecular Approaches ◽  
Salix Babylonica

Summary Whilst investigating plant-parasitic nematodes in Urmia City, West Azerbaijan, Iran, soil samples were collected from the rhizosphere of willow trees (Salix babylonica) known to have a population of cyst nematodes. Morphological, numerical and molecular approaches revealed that this population represented the willow cyst nematode, Heterodera salixophila, the first report of this species from Iran. Reproduction of the nematode on S. babylonica was confirmed by inoculating 5000 viable eggs and second-stage juveniles (J2) per kg soil on 2-year-old seedlings of S. babylonica grown in pots containing sterilised soil and incubated under glasshouse conditions. Principal Component Analysis (PCA) and hierarchical cluster analysis of morphometric characters of J2 and vulval plates of species within the Humuli group supported the separation of H. salixophila from other species in this group. In the ITS-rRNA phylogenetic tree, the Iranian population of H. salixophila formed a cluster with two other populations of the species from Belgium and Ukraine, while in the D2-D3 expansion segments of the 28S rRNA tree, it grouped with a population from Belgium as a basal clade in the Humuli group.

scholarly journals First Report of Ditylenchus dipsaci on Garlic in Minnesota

Plant Disease ◽  
2012 ◽  
Vol 96 (11) ◽  
pp. 1707-1707 ◽  
Author(s):  
D. S. Mollov ◽  
S. A. Subbotin ◽  
Carl Rosen
Keyword(s):  
The Body ◽  
Parasitic Nematodes ◽  
Rrna Gene ◽  
28S Rrna ◽  
Gene Sequences ◽  
Surrounding Water ◽  
Pharyngeal Bulb ◽  
First Report ◽  
Plant Parts ◽  
Ditylenchus Dipsaci

In the summer of 2011, two independent garlic samples from Morrison and Dakota counties and in 2012 one garlic sample from Carver county in Minnesota were submitted by commercial growers to the University of Minnesota Plant Disease Clinic for disease analyses. Symptoms of the above-ground plant parts were stunting and chlorosis. Symptoms of bulbs were necrosis, underdevelopment, and distortion. Upon microscopic examination, phytonematodes exuded into the surrounding water droplet. Nematodes were present in the protective leaves, abscission zone, and cloves in all submitted bulbs (n = 18) for analyses. Morphometric examination of females, males, and juveniles determined that they were Ditylenchus dipsaci. Nematodes extracted from garlic cloves were fixed in TAF (97 ml formalin [40%], 2 ml triethanolamine, and 91 ml dH2O). Morphological observations and measurements were made under an Olympus BX51 microscope equipped with a Nomarski differential interference contrast. Female (n = 6) measurements were: L = 1.411 to 1.636 mm, a = 38 to 44, b = 5.8 to 8.0, c = 14 to 17, stylet = 11.5 to 12.3 μm, V = 79 to 81%, and tail = 95 to 105 μm. The body was almost straight, when heat relaxed, lip region flattened, median bulb oval, and isthmus elongate and slender. The basal pharyngeal bulb overlapped the intestine. The post-vulval uterine branch was about half of vulva-anus distance. The tail was conoid with a pointed terminus. Male (n = 9) measurements were: L = 1.372 to 1.558 mm, a = 40 to 50, b = 6.5 to 7.0, c = 14 to 16, stylet = 11.5 to 12.3 μm, spicules = 22 to 27 μm, and gubernaculum = 9 to 10 μm. The bursa was leptoderan and spicules were curved with simple gubernaculum. Morphology and morphometrics of females and males of D. dipsaci from Minnesota generally fit the descriptions provided for the type and other populations by Hopper (1) and other authors. Several specimens were also taken for molecular identification. DNA extraction, PCR, and sequencing protocols were as described by Subbotin et al. (2). The TW81 and AB28 primers were used for amplification of ITS-rRNA region and the D2A and D3B primers were used for amplification of the D2-D3 expansion segments of 28S rRNA gene. Comparison of the ITS and D2-D3 of 28 rRNA gene sequences showed 100 and 99% identity with corresponding gene sequences of D. dipsaci published in the GenBank (2). The sequences were submitted in the GenBank under accession numbers JX123258 and X123259. This nematode problem has not been known to occur in either of these locations previously. The most likely source of introduction of D. dipsaci are imported garlic seed bulbs. To our knowledge, this is the first report of D. dipsaci affecting garlic or any other crops in Minnesota. The garlic produced in these locations was considered unmarketable and complete loss to the farmers. The presence of D. dipsaci could have a significant economic impact in the emerging multi-million dollar garlic industry in Minnesota. References: (1) D. J. Hooper. Ditylenchus dipsaci. CIH Descriptions of Plant-Parasitic Nematodes Set 1, No. 14, 1972. (2) S. A. Subbotin et al. Phytopathology 95:1308, 2005.

scholarly journals Saksenaea dorisiae sp. nov., a New Opportunistic Pathogenic Fungus from Europe

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Roman Labuda ◽  
Andreas Bernreiter ◽  
Doris Hochenauer ◽  
Christoph Schüller ◽  
Alena Kubátová ◽  
...  
Keyword(s):  
Pathogenic Fungus ◽  
Elongation Factor ◽  
Its Region ◽  
Rrna Gene ◽  
28S Rrna ◽  
New Taxon ◽  
Translation Elongation ◽  
The Republic ◽  
Opportunistic Pathogenic ◽  
Continental Climate

A new species, Saksenaea dorisiae (Mucoromycotina, Mucorales), isolated from a water sample originating from a private well in Manastirica, Petrovac, in the Republic of Serbia (Europe), is described and illustrated. The new taxon is well supported by multilocus phylogenetic analysis that included the internal transcribed spacer (ITS) region, domains D1 and D2 of the 28S rRNA gene (LSU), and translation elongation factor-1α gene (tef-1α), and it is resolved in a clade with S. oblongispora and S. trapezispora. This fungus is characterized by its moderately slow growth at 15 and 37°C, sparse rhizoids, conical-shaped sporangia, and short-cylindrical sporangiospores. Saksenaea dorisiae is a member of the opportunistic pathogenic genus often involved in severe human and animal mucormycoses encountered in tropical and subtropical regions. Despite its sensitivity to several conventional antifungals (terbinafine and ciclopirox), the fungus can potentially evoke clinically challenging infections. This is the first novel taxon of the genus Saksenaea described from the moderately continental climate area of Europe.

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