scholarly journals First Report of Meloidogyne marylandi Infecting Bermudagrass in Oklahoma

Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1286-1286 ◽  
Author(s):  
N. Walker
Keyword(s):  
Cynodon Dactylon ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Similar Species ◽  
Root Knot Nematode ◽  
Putting Greens ◽  
Egg Masses ◽  
First Report ◽  
Mean Width ◽  
Ultradwarf Bermudagrass

Meloidogyne marylandi is a nematode commonly associated with turfgrasses and has been reported to occur in Texas and Arkansas (1,3). In the fall of 2013, a stand of ultradwarf bermudagrass (Cynodon dactylon × C. transvaalensis) plants in a sand-based, research putting green in Stillwater, Oklahoma, exhibited symptoms of decline. Roots of the affected plants had small galls and upon staining of the root system, numerous egg masses were evident. Egg masses were collected, placed in water, and the morphology of 20 hatched, second-stage juveniles were examined. The characteristics of the juveniles were: body length averaged 393.1 ± 19.87 (range: 361 to 425) μm, mean width averaged 16.6 ± 0.7 (15.6 to 17.8) μm, stylet lengths averaged 12.1 ± 0.7 (10.4 to 12.9) μm, dorsal gland orifice from stylet base averaged 2.9 ± 0.4 (2.5 to 3.6) μm, tail lengths averaged 53.7 ± 3.8 (46.2 to 60.4) μm, and the hyaline region of the tails averaged 10.4 ± 1.1 (8.4 to 12.7) μm. Genomic DNA was extracted from six females that were removed from roots. Amplification and sequencing of the mitochondrial DNA region between COII and 16S rRNA genes was performed with primers 1RNAF (5′-TACCTTTGACCAATCACGCT-3′) and CO11R (5′-GGTCAATGTTCAGAAATTTGTGG-3′) as previously described (2). A PCR product approximately 510 bp in length was obtained and sequenced at the Oklahoma State University Core Facility. Sequences were compared with those in NCBI's nucleotide database using BLAST and had 97% identity with two sequences from M. marylandi (KC473862.1 and KC473863.1) and the next most similar species being M. graminis (JN241898.1) with 83% identity. To our knowledge, this is the first report of the root-knot nematode M. marylandi in Oklahoma. As bermudagrass becomes more commonly used for putting greens in the turfgrass transition zone, M. marylandi may become a more common and damaging pathogen in the region. References: (1) A. A. Elmi et al. Grass For. Sci. 55:166, 2000. (2) M. A. McClure et al. Plant Dis. 96:635, 2012. (3) J. L. Starr et al. Nematrop. 37:43, 2007.

scholarly journals First Report of Meloidogyne marylandi Infecting Bermudagrass in Costa Rica

Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 1005-1005 ◽  
Author(s):  
L. Salazar ◽  
M. Gómez ◽  
L. Flores ◽  
L. Gómez-Alpízar
Keyword(s):  
Costa Rica ◽  
Cynodon Dactylon ◽  
Tail Length ◽  
Bootstrap Support ◽  
Root Knot Nematode ◽  
First Report ◽  
Pcr Product ◽  
Mean Width ◽  
Lateral Lines ◽  
Grass Root

Bermudagrass plants (Cynodon dactylon cv. 419) from a soccer field in Santa Ana, San Jose Province, Costa Rica, were found with symptoms of decline with dried leaves and leaf yellowing in patches in February 2012. Roots of the affected plants presented small and smooth galls and protruding egg masses similar to those associated with root-knot nematodes (RKN), Meloidogyne spp. Morphometric and molecular analyses were conducted to identify the species present. Morphological measurements from 30 second-stage juveniles and perineal patterns from 10 adult females matched the description of Meloidogyne marylandi Jepson and Golden. Body length averaged 429.5 ± 18.5 (range: 392 to 459) μm, mean width averaged 16.0 ± 1.3 (range: 13.2 to 18.0) μm, stylet lengths averaged 10.7 ± 1.0 (range: 9.1 to 13.4) μm, dorsal gland orifice from stylet base averaged 2.8 ± 0.3 (range: 2.4 to 3.4) μm, tail lengths averaged 60.9 ± 4.9 (range: 45.5 to 74.7) μm, and the hyaline region of the tails averaged 12.4 ± 1.4 (range: 8.6 to 14.8) μm. Lower average tail length and hyaline tail terminal differentiate M. marylandi from the closely related species M. graminis, the grass root-knot nematode, that can also parasitize bermudagrass (1). Hemizonid position was posterior to the excretory pore. The overall shape of the perineal patterns was ovoid, and the dorsal arch was medium high with lateral lines and coarse striae. Males were rarely observed. DNA was extracted from 10 single mature females. Amplification and sequencing of the mitochondrial DNA region between COII and the lRNA gene was accomplished with primers C2F3 (5′-GGTCAATGTTCAGAAATTTGTGG-3′) and 1108 (5′-TACCTTTGACCAATCACGCT-3′) (2). A PCR product approximately 520 bp in length was obtained and the sequence (GenBank Accession Nos. KC473862 and KC473863) was compared with those in GenBank using BLAST and showed 99 to 100% identity with known sequences of M. marylandi (JN241916.1, JN241905.1, JN241917.1, JN241921.1, and JN241955.1) (3). Phylogenetic analysis with maximum likelihood (MEGA v.5.0) (4) of those sequences placed the Meloidogyne sp. from Costa Rica in a clade (100% bootstrap support) that included only M. marylandi sequences available from the GenBank database, thus confirming its identity. In addition, digestion of the PCR product with SspI restriction enzyme produced a four band pattern similar to what has been reported for M. marylandi from Israel and United States (Maryland) and this approach is considered useful for the separation of M. marylandi from M. graminis (3). To our knowledge, this is the first report of the root-knot nematode M. marylandi in Costa Rica. References: (1) A. M. Golden. J. Nematol. 21:453, 1989. (2) T. O. Powers and T. S. Harris. J. Nematol. 25:1, 1993. (3) M. A. McClure et al. Plant Dis. 96:635, 2012. (4) K. Tamura et al. Mol Biol Evol. 28:2731, 2011.

scholarly journals First Report of Meloidogyne partityla on Pecan in New Mexico

Plant Disease ◽  
2001 ◽  
Vol 85 (9) ◽  
pp. 1030-1030 ◽  
Author(s):  
S. H. Thomas ◽  
J. M. Fuchs ◽  
Z. A. Handoo
Keyword(s):  
New Mexico ◽  
The United States ◽  
Root Knot Nematode ◽  
Carya Illinoensis ◽  
Morphological Examination ◽  
Egg Masses ◽  
First Report ◽  
Additional Information ◽  
Dona Ana County ◽  
Normal Fertilization

For several years, decline was observed in mature pecan (Carya illinoensis (F.A. Wangenheim) K. Koch) trees in an orchard in Dona Ana County, New Mexico despite normal fertilization and irrigation practices. Affected trees were growing in sandy soil in two widely separated irrigation terraces and exhibited chlorosis of foliage and substantial die-back of branches in the upper canopy. Examination of feeder roots revealed the presence of numerous small galls and egg masses, with root-knot nematode females often visibly protruding from root tissue. Attempts to culture the nematode on tomato (Lycopersicon esculentum Mill. ‘Rutgers’) were unsuccessful. Females and egg masses were collected from fresh pecan roots and sent to the USDA Nematology Laboratory in Beltsville, MD, in October 2000, where specimens were identified as Meloidogyne partityla Kleynhans (1) based on morphological examination. This is the first report of M. partityla from New Mexico, and the second report of this nematode outside South Africa. Starr et al. (2) first reported M. partityla from pecan in the United States in 1996, after recovering the nematode from five orchards in Texas. In their study, the host range of M. partityla was limited to members of the Juglandaceae, which may explain the inability of the New Mexico population to reproduce on tomato. Additional information is needed regarding distribution of this nematode within pecan-growing regions throughout North America. References: (1) K. P. N. Kleynhans. Phytophylactica 18:103, 1986. (2) J. L. Starr et al. J. Nematol. 28:565, 1996.

scholarly journals Nitrifying Microbes in the Rhizosphere of Perennial Grasses Are Modified by Biological Nitrification Inhibition

2020 ◽  
Vol 8 (11) ◽  
pp. 1687
Author(s):  
Yi Zhou ◽  
Christopher J. Lambrides ◽  
Jishun Li ◽  
Qili Xu ◽  
Ruey Toh ◽  
...  
Keyword(s):  
Cynodon Dactylon ◽  
Perennial Grasses ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Soil Microbiome ◽  
Nitrification Inhibition ◽  
Microbial Oxidation ◽  
Seashore Paspalum ◽  
Soil Nitrification ◽  
Biological Nitrification

Soil nitrification (microbial oxidation of ammonium to nitrate) can lead to nitrogen leaching and environmental pollution. A number of plant species are able to suppress soil nitrifiers by exuding inhibitors from roots, a process called biological nitrification inhibition (BNI). However, the BNI activity of perennial grasses in the nutrient-poor soils of Australia and the effects of BNI activity on nitrifying microbes in the rhizosphere microbiome have not been well studied. Here we evaluated the BNI capacity of bermudagrass (Cynodon dactylon L.), St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze), saltwater couch (Sporobolus virginicus), seashore paspalum (Paspalum vaginatum Swartz.), and kikuyu grass (Pennisetum clandestinum) compared with the known positive control, koronivia grass (Brachiaria humidicola). The microbial communities were analysed by sequencing 16S rRNA genes. St. Augustinegrass and bermudagrass showed high BNI activity, about 80 to 90% of koronivia grass. All the three grasses with stronger BNI capacities suppressed the populations of Nitrospira in the rhizosphere, a bacteria genus with a nitrite-oxidizing function, but not all of the potential ammonia-oxidizing archaea. The rhizosphere of saltwater couch and seashore paspalum exerted a weak recruitment effect on the soil microbiome. Our results demonstrate that BNI activity of perennial grasses played a vital role in modulating nitrification-associated microbial populations.

scholarly journals Ficus microcarpa Bonsai “Tiger bark” Parasitized by the Root-Knot Nematode Meloidogyne javanica and the Spiral Nematode Helicotylenchus dihystera, a New Plant Host Record for Both Species

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1085
Author(s):  
Duarte Santos ◽  
Isabel Abrantes ◽  
Carla Maleita
Keyword(s):  
Host Record ◽  
The Body ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Parasitic Nematodes ◽  
Soil Nematode ◽  
Root Knot Nematode ◽  
Plant Host ◽  
Meloidogyne Spp ◽  
Ficus Microcarpa

In December 2017, a Ficus microcarpa “Tiger bark” bonsai tree was acquired in a shopping center in Coimbra, Portugal, without symptoms in the leaves, but showing small atypical galls of infection caused by root-knot nematodes (RKN), Meloidogyne spp. The soil nematode community was assessed and four Tylenchida genera were detected: Helicotylenchus (94.02%), Tylenchus s.l. (4.35%), Tylenchorynchus s.l. (1.09%) and Meloidogyne (0.54%). The RKN M. javanica was identified through analysis of esterase isoenzyme phenotype (J3), PCR-RFLP of mitochondrial DNA region between COII and 16S rRNA genes and SCAR-PCR. The Helicotylenchus species was identified on the basis of female morphology that showed the body being spirally curved, with up to two turns after relation with gentle heat, a key feature of H. dihystera, and molecular characterization, using the D2D3 expansion region of the 28S rDNA, which revealed a similarity of 99.99% with available sequences of the common spiral nematode H. dihystera. To our knowledge, M. javanica and H. dihystera are reported for the first time as parasitizing F. microcarpa. Our findings reveal that more inspections are required to detect these and other plant-parasitic nematodes, mainly with quarantine status, to prevent their spread if found.

scholarly journals Root-Knot Nematodes in Golf Course Greens of the Western United States

Plant Disease ◽  
2012 ◽  
Vol 96 (5) ◽  
pp. 635-647 ◽  
Author(s):  
Michael A. McClure ◽  
Claudia Nischwitz ◽  
Andrea M. Skantar ◽  
Mark E. Schmitt ◽  
Sergei A. Subbotin
Keyword(s):  
United States ◽  
Western Hemisphere ◽  
Western United States ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Golf Course ◽  
28S Rrna ◽  
Golf Courses ◽  
Root Knot Nematodes ◽  
First Report

A survey of 238 golf courses in 10 states of the western United States found root-knot nematodes (Meloidogyne spp.) in 60% of the putting greens sampled. Sequence and phylogenetic analyses of 18S rRNA, D2-D3 of 28S rRNA, internal transcribed spacer-rRNA, and mitochondrial DNA gene sequences were used to identify specimens from 110 golf courses. The most common species, Meloidogyne naasi, was found in 58 golf courses distributed from Southern California to Washington in the coastal or cooler areas of those states. In the warmer regions of the Southwest, M. marylandi was recovered from 38 golf courses and M. graminis from 11 golf courses. This constitutes the first report of M. marylandi in Arizona, California, Hawaii, Nevada, and Utah, and the first report of M. graminis in Arizona, Hawaii, and Nevada. Two golf courses in Washington were infested with M. minor, the first record of this nematode in the Western Hemisphere. Columbia root-knot nematode, M. chitwoodi, was found in a single golf course in California. Polymerase chain reaction restriction fragment length polymorphism of the intergenic region between the cytochrome oxidase and 16S rRNA genes in the mitochondrial genome with restriction enzyme SspI was able to distinguish populations of M. graminis from M. marylandi, providing a fast and inexpensive method for future diagnosis of these nematodes from turf.

scholarly journals First Detection of Meloidogyne luci (Nematoda: Meloidogynidae) Parasitizing Potato in the Azores, Portugal

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 99
Author(s):  
Leidy Rusinque ◽  
Filomena Nóbrega ◽  
Laura Cordeiro ◽  
Clara Serra ◽  
Maria L. Inácio
Keyword(s):  
Biochemical Characterization ◽  
Economic Importance ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Root Knot Nematode ◽  
Cytochrome Oxidase Subunit ◽  
Additional Information ◽  
Second Stage ◽  
The One ◽  
Cytochrome Oxidase Subunit Ii

Potato is the third most important crop in the world after rice and wheat, with a great social and economic importance in Portugal as it is grown throughout the country, including the archipelagos of Madeira and the Azores. The tropical root-knot nematode (RKN) Meloidogyne luci is a polyphagous species with many of its host plants having economic importance and the ability to survive in temperate regions, which pose a risk to agricultural production. In 2019, M. luci was detected from soil samples collected from the council of Santo António in Pico Island (Azores). Bioassays were carried out to obtain females, egg masses, and second-stage juveniles to characterize this isolate morphologically, biochemically, and molecularly. The observed morphological features and morphometrics showed high similarity and consistency with previous descriptions. Concerning the biochemical characterization, the esterase (EST) phenotype displayed a pattern with three bands similar to the one previously described for M. luci and distinct from M. ethiopica. Regarding the molecular analysis, an 1800 bp region of the mitochondrial DNA between cytochrome oxidase subunit II (COII) and 16S rRNA genes was analyzed and the phylogenetic tree revealed that the isolate grouped with M. luci isolates (99.17%). This is the first report of M. luci parasitizing potato in the Azores islands, contributing additional information on the distribution of this plant-parasitic nematode.

Phylogenetic relationships and diversity of β-rhizobia associated with Mimosa species grown in Sishuangbanna, China

2011 ◽  
Vol 61 (2) ◽  
pp. 334-342 ◽  
Author(s):  
Xiao Yun Liu ◽  
Wei Wu ◽  
En Tao Wang ◽  
Bin Zhang ◽  
Jomo Macdermott ◽  
...  
Keyword(s):  
16S Rrna ◽  
Phylogenetic Relationships ◽  
Phenotypic Diversity ◽  
Mainland China ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Whole Cell ◽  
First Report ◽  
Sds Page

In order to investigate the genetic diversity of rhizobia associated with various exotic and invasive species in tropical mainland China, 116 bacterial isolates were obtained from Mimosa root nodules collected from Sishuangbanna and Yuanjiang districts of Yunnan province. Isolated rhizobia were characterized by RFLP analysis of 16S rRNA genes, SDS-PAGE of whole-cell proteins and BOX-PCR. Most of the isolated strains were identified as β-rhizobia belonging to diverse populations of Burkholderia and Cupriavidus, and the phylogenetic relationships of their 16S rRNA gene sequences showed that they were closely related to one of four β-rhizobia species: Burkholderia phymatum, B. mimosarum, B. caribensis or Cupriavidus taiwanensis. Additionally, among the 116 isolates, 53 different whole-cell SDS-PAGE profiles and 30 distinct BOX-PCR genotypic patterns were detected, which demonstrated the genetic and phenotypic diversity found within these Burkholderia and Cupriavidus strains. To the best of our knowledge, this is the first report that β-rhizobia are extant and possibly widespread on the Chinese mainland and nodulate easily with Mimosa plants. We also find it especially interesting that this appears to be the first report from mainland China of Cupriavidus symbionts of Mimosa. These records enrich our knowledge and understanding of the geographical distribution and diversity of these bacteria.

scholarly journals First Report of Streptomyces stelliscabiei Causing Potato Common Scab in Michigan

Plant Disease ◽  
2012 ◽  
Vol 96 (6) ◽  
pp. 904-904 ◽  
Author(s):  
H. H. Jiang ◽  
Q. X. Meng ◽  
L. E. Hanson ◽  
J. J. Hao
Keyword(s):  
Dna Sequences ◽  
Common Scab ◽  
Solanum Tuberosum L ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Malt Extract ◽  
Potato Tubers ◽  
First Report ◽  
Streptomyces Spp ◽  
Potato Common Scab

Potato (Solanum tuberosum L.) common scab can be caused by multiple Streptomyces spp., with S. scabies as a predominant species (2,3). However, according to our survey in August 2007, many symptomatic potato tubers did not have S. scabies in Michigan. To identify the pathogen, potato tubers with scab symptoms were collected from two fields in Michigan, and Streptomyces spp. were isolated using Streptomyces selective medium (STR) (2). Pure cultures of the isolates were obtained by transferring single colonies and incubation at 28°C on STR. Three isolates, designated HER21, HER24, and HER26, were identified as Streptomyces stelliscabiei based on morphological and physiological characterization (1). Bacterial cultures were prepared in liquid yeast malt extract at 28°C on an incubator shaker at 150 rpm. Genomic DNA was extracted from the cultures and used as a template for PCR with species-specific primers for Streptomyces spp. (4). The isolates gave a positive PCR reaction with primers Stel3 and T2st2 for S. stelliscabiei, but negative for any other Streptomyces spp. reported as pathogenic to potato. The 16S rRNA genes were amplified using primers previously reported (4) and amplicons were sequenced and submitted to GenBank (Accession Nos. HM018115, HM018116, and HM018117 for the three isolates, respectively). BLAST analysis of these sequences against the NCBI GenBank database determined these sequences to have 99 to 100% sequence identity with S. stelliscabiei sequences such as Accession No. FJ546728 (4). These isolates were all confirmed by PCR, using the same conditions described above, to have txtAB, nec1, and tomA genes (4), which are associated with pathogenicity of scab-causing Streptomyces spp. To complete Koch's postulates, cell suspensions of the isolates were mixed in vermiculate media (3) at a final concentration of 106 colony-forming units/ml, which were used as inocula. Potato (cv Snowden) tubers were incubated in sterilized potting mix in a growth chamber at 25°C until the seed germinated. Each potato seedling was transferred to a new pot in the greenhouse. Two weeks later, the potting mix was infested with the bacterial spore suspensions of either HER21, HER24, or HER26, with five pots per isolate. Potting mix with only media or media with S. scabies isolate 49173 were used as negative and positive controls, respectively. Three months later, potato tubers were harvested and evaluated for scab symptoms (3). The experiment was done twice. Potato tubers inoculated with either S. stelliscabiei or S. scabies exhibited superficial, raised, or pitted scabby symptoms, and no symptoms were observed on tubers grown in noninfested potting mix. Disease index values from the combined trials averaged 0, 37.8, 26.5, 11.1, and 30.5% for negative control and isolates HER21, HER24, HER26, and 49173, respectively. The pathogen was reisolated from the lesions and confirmed identical to the original isolate by DNA sequences. To our knowledge, this is the first report of S. stelliscabiei causing potato common scab in Michigan (4). References: (1) K. Bouchek-Mechiche et al. Int. J. Syst. Evol. Microbiol. 50:91, 2000. (2) Conn et al. Plant Dis. 82:631, 1998. (3) Hao et al. Plant Dis. 93:1329, 2009. (4) L. A. Wanner. Am. J. Potato Res. 86:247, 2009.

scholarly journals First Report of Limonomyces roseipellis Causing Pink Patch on Bermudagrass in South China

Plant Disease ◽  
2013 ◽  
Vol 97 (4) ◽  
pp. 561-561 ◽  
Author(s):  
W. Zhang ◽  
Z. B. Nan ◽  
G. D. Liu
Keyword(s):  
Cynodon Dactylon ◽  
Southern China ◽  
Morphological Characteristics ◽  
Golf Course ◽  
Fungal Mycelium ◽  
Putting Greens ◽  
First Report ◽  
Plastic Bags ◽  
Putting Green ◽  
Pathogenicity Tests

Hybrid bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy) is widely used on golf course putting greens in southern China. In September 2011, circular pink patches ranging from 10 to 20 cm in diameter were observed on putting greens established with cv. ‘Tifgreen’ on a golf course in Haikou, Hainan Province. There were approximately 50 pink patches on a putting green. Infected leaves were covered with pink, gelatinous fungal mycelium, which resulted in the production of chlorotic lesions. Lesions expanded, became water-soaked, and leaves died basipetally. A pink fungus, characterized by the presence of clamp connections, was consistently isolated from leaves of infected plants on a potato dextrose agar amended with 0.01% gentamicin sulfate. Based on morphological characteristics, the fungus was preliminary identified as Limonomyces roseipellis Stalpers & Loerakker, the causal agent of pink patch of turfgrass (2,3). To verify the identity, the internal transcribed spacer (ITS) of rDNA was amplified and sequenced using primers ITS1 and ITS4. Comparison with sequences in the GenBank database revealed that the ITS sequence (Accession No. KC193592) showed 98% homology with the sequence of L. roseipellis (EU622846). For pathogenicity tests, inoculum was prepared by culturing the fungus on an autoclaved mixture of 100 g of rye grain and 20 ml water for 3 weeks at 25°C. Six-week-old C. dactylon plants in 10-cm pots were inoculated by placing 2 g of infested grain in the center of the turf canopy, or 2 g sterilized, uninfested grain as a control, with four replications of each treatment. After inoculation, pots were covered with translucent plastic bags and placed in a greenhouse at 24 ± 2°C with a 12-h photoperiod (1). After 3 weeks, more than 70% of leaves in the infested pots showed symptoms identical to those observed under natural conditions while control plants remained asymptomatic. The fungus was reisolated from symptomatic plants. To our knowledge, this is the first report of L. roseipellis causing pink patch on hybrid bermudagrass in China. References: (1) L. L. Burpee and L. G. Goulty. Phytopathology 74:692, 1986. (2) J. D. Kaplan and N. Jackson. Plant Dis. 67:159, 1983. (3) J. A. Stalpers and W. M. Loerakker. Can. J. Bot. 60:529, 1982.

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