scholarly journals First Report of Stemphylium eturmiunum causing postharvest rot on tomato (Solanum lycopersicum) in Italy

Plant Disease ◽  
2021 ◽  
Author(s):  
Simona Prencipe ◽  
Davide Spadaro
Keyword(s):  
Solanum Lycopersicum ◽  
Sodium Hypochlorite ◽  
Dna Sequences ◽  
Control Strategies ◽  
The United States ◽  
Gene Region ◽  
First Report ◽  
Gapdh Gene ◽  
Careful Handling ◽  
Postharvest Rot

Italy is the largest tomato (Solanum lycopersicum)-producing country in Europe with a cultivated area of 97,092 ha and a production of 5,798,103 tons/year in 2018 (FAOSTAT, 2020). During July 2020, a postharvest rot occurred in fresh tomatoes ‘Piccadilly’ cultivated in Sicily (Pachino, RG) and commercialized in Northern Italy (Torino, TO). Affected fruit showed circular black rot on the blossom end. The rot had an average incidence of 7% of the fruits, in three batches of 100 tomatoes each. Isolation was carried out by cutting pieces of symptomatic rotten fruits. The fragments were surface-disinfected with 1% sodium hypochlorite for 30 s, rinsed in sterile water and air-dried. Five fragments were cut and plated onto Potato Dextrose Agar (PDA) supplemented with streptomycin, and incubated at 24±1°C in the dark for 5 days. Representative colonies were transferred onto PCA and morphological observations were performed as described by Woudenberg et al. (2017) after 7 and 14 days. Colonies were olive-green, flat with regular margins, while conidia were mid to deep brown, solitary, ovoid or ellipsoid (17.39 µm ± 2.04 × 10.59 ± 3.30 µm) with transverse and longitudinal septa. Based on morphological observations the isolates were identified as Stemphylium eturmiunum (Simmons, 2001). Species identification was confirmed by sequencing rDNA internal transcribed spacer (ITS) using primers ITS1/ITS4 (White et al. 1990), cmdA gene region using primers CALDF1/CALDR2 (Lawrence et al. 2013) and gapdh gene region with primers gpd1/gpd2 (Berbee et al. 1999). Six amplified sequences per region (ANos. from MW158387 to MW158398 and from MW159746 to MW159751) were BLAST-searched in GenBank, obtaining >99 % identity with ex-type strain of S. eturmiunum strain CBS 109845 (AN° KU850541) for ITS, and 100% identity (ANos. KU850831 and KU850689) for cmdA and gapdh, respectively. To confirm the species, DNA sequences were aligned with CLUSTAL W with closely related species of Stemphylium reported in the last revision of the genus (Woudenberg et al., 2017), and a phylogenetic analysis with the Neighbor Joining method based on Tamura Nei model + Gamma distribution (bootstrap 1,000) was performed. The phylogenetic tree confirmed the identity of the isolates as S. eturmiunum (Suppl. Fig. 1). To fulfil Koch’s postulates, pathogenicity tests were conducted on S. lycopersicum cv. Piccadilly fruits. Tomatoes were surface sterilized with 1% sodium hypochlorite and air-dried. Fruits (5 fruits per isolates) were wounded (two injuries of 3 mm each) and inoculated with a spore suspension of 1x105 cell/mL obtained from 15 days-old PCA cultures, as in Spadoni et al. (2020. Negative controls were wounded and inoculated with sterile deionized water. Symptoms occurred on all fruits inoculated after 12 days at 24±1°C and S. eturmiunum was re-isolated from inoculated fruits on PCA (Suppl. Fig. 2), control remained symptomless. Re-isolated colonies were molecularly identified as S. eturmiunum. In Italy a different species, S. vesicarium, was reported on tomato (Porta-Puglia, 1981), while S. eturmiunum was described as a postharvest pathogen of tomato in China, Greece, New Zealand and the United States (Woudenberg et al., 2017; Vaghefi et al., 2020), and from fruits commercialized in Danish and Spanish markets (Andersen and Frisvad, 2004). To the best of our knowledge, this is the first report of S. eturmiunum causing postharvest rot on tomato in Italy. The occurrence of this pathogen further stresses the importance of careful handling to prevent fruit crackings and of preharvest control strategies.

scholarly journals First Report of Coleosporium helianthi infecting Helianthus verticillatus (Whorled Sunflower)in the United States

Plant Disease ◽  
2021 ◽  
Author(s):  
Robert N. Trigiano ◽  
Sarah L. Boggess ◽  
Michelle Odoi ◽  
Denita Hadziabdic ◽  
Ernest C. Bernard ◽  
...  
Keyword(s):  
United States ◽  
Dna Sequences ◽  
The United States ◽  
Control Measures ◽  
Control Treatment ◽  
Adaxial Side ◽  
Adaxial Surface ◽  
First Report ◽  
Leaf Surfaces ◽  
Pinus Spp

Helianthus verticillatus, the whorled sunflower, is an endangered species found only in the southern United States (Trigiano et al. 2021) that is being developed for ornamental uses. This sunflower species requires little to no maintenance, produces spectacular floral displays from September into October, and attracts numerous potential pollinators including many native bees (Strange et al. 2020). In June and July of 2021, chlorotic, irregularly shaped spots were observed on the adaxial surface of mature leaves of two vegetatively produced clones of H. verticillatus (Trigiano et al., 2021) at three locations in Knoxville, TN. In September, yellow (4A, Royal Horticultural Society Color Chart) sori were abundant on abaxial surfaces and more rarely on the adaxial leaf surfaces of both clones at all locations. Globose-to-cylindrical, yellow urediniospores were 23.7µm (20-32) x 18.9 (16-22) µm (n = 30) with irregular, verrucose ornamentation. The morphology and dimensions of the urediniospores were similar to other Coleosporium species (e.g., C. asterum, Back et al., 2014). Telia were waxy, red-brown (167A; B) and developed in October with colder temperatures. Cylindrical teliospores were sessile, 1-celled, thin-walled with basidia ca. 93 µm (70-117) x 25 µm (19-29), consistent with spores of C. helianthi (Cummins, 1978). DNA was obtained from urediniospores using a Phire kit (ThermoFisher Scientific, Waltham, MA) and the 28S rDNA region was amplified using the NL1 and NL4 primers (Back et al. 2014) (Genbank accession # OL364847) as well as ITS 1-4 primers (White et al. 1990) (GenBank accession OL364848). For comparison, DNA sequences were also obtained from authentic C. helianthi on H. divaricatus in the Arthur Fungarium at Purdue University (#PURN11678; GenBank accession OL364846) using the protocols of Aime et al. (2018). 28S sequences shared 99.65% (568/570 bp) identity. To test Koch’s postulates, seven healthy detached leaves were lightly brushed on both leaf surfaces with leaves with uredia producing urediniospores. The leaves were incubated adaxial side up in 9-cm-diameter Petri dishes on moistened filter paper at ambient laboratory conditions. A similar number of healthy leaves were brushed with healthy leaves, incubated in the laboratory and served as the control treatment. After 7-10 days, uredia with urediniospores formed primarily on the abaxial leaf surface, but a few were present on the adaxial surface of leaves treated with urediniospores, whereas the leaves in the control remained healthy. Molecular, morphological and infectivity studies identified C. helianthi as the pathogen. Coleosporium helianthi occurs on the commercial sunflower, H. annuus, and several wild sunflower species, including H. tuberosum (Jerusalem artichoke) and H. microcephalus (small-headed sunflower), among others in the southern U.S. (Farr and Rossman 2021). Coleosporium species are heteroecious and mostly macrocyclic rusts (McTaggart and Aime, 2018) with aecia and aeciospores typically found on pines (Pinus spp.). Although H. verticillatus is very susceptible to rust infection and it probably reduces photosynthetic capability, it does not appear to adversely affect flowering in the fall. The disease primarily degrades the aesthetic appeal of the plant but does not require control measures. To our knowledge, this is the first report of C. helianthi infecting H. verticillatus. Voucher material is deposited in the Arthur Herbarium (#PURN23470).

scholarly journals First Report of Root Rot Caused by Fusarium solani on Benincasa hispida in the United States

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 294-294 ◽  
Author(s):  
P. Ji ◽  
J. Yin ◽  
K. L. Jackson
Keyword(s):  
United States ◽  
Dna Sequences ◽  
Root Rot ◽  
Morphological Characteristics ◽  
The United States ◽  
First Report ◽  
Benincasa Hispida ◽  
Field Samples ◽  
Vegetable Farm ◽  
Wax Gourd

Root rot was observed on wax gourd (Benincasa hispida (Thunb.) Cogn.) cv. Black Giant in August 2010 in a commercial vegetable farm in southern Georgia. Approximately 5% of the plants were affected and infected roots turned light to dark brown with partial or entire roots affected and the lower leaves became wilted. Symptomatic roots from six plants were surface sterilized with 0.6% sodium hypochlorite and plated on potato dextrose agar (PDA) medium. Pure cultures had white mycelia and spore masses and were obtained from all six plants by subculturing hyphal tips onto PDA. One- to two-celled, oval- to kidney-shaped microconidia and cylindrical macroconidia with two or three cells plus apical and basal cell were produced, which averaged 12.5 × 4 μm and 28 × 4.5 μm, respectively. Microconidia were abundant and macroconidia were sparse on PDA. Single-spore isolates were obtained and identified as a Fusarium sp. by PCR analysis with primers ITS-Fu-f and ITS-Fu-r (1). Genomic DNA of two isolates obtained from different plants was extracted and a portion of the translation elongation factor 1-α (TEF) gene of the isolates was amplified and sequenced (3). When compared with sequences available in the GenBank database, DNA sequences of the two isolates (GenBank Accession No. JF928376) shared 100% sequence identity with F. solani strain FRC S1734 (GenBank Accession No. DQ247527). The fungus was identified as F. solani (Mart.) Sacc. based on molecular analysis and morphological characteristics (2). Oat grains were separately infected with two isolates, BG2a and BG6, and used to inoculate healthy, 3-week-old wax gourd seedlings (cv. Black Giant) under greenhouse conditions (14-h photoperiod, 24 to 30°C). Each seedling was grown in a 10-cm pot containing a commercial potting mix, and five healthy plants were inoculated with each isolate by placing 15 infected oat grains around each plant at a depth of 5 cm in the soil. Five plants treated with noninfected oat grains served as controls. Symptoms identical to those on field samples developed on all inoculated plants 3 weeks after inoculation but not on the control plants. F. solani was reisolated from inoculated symptomatic plants and the identity was confirmed, which completed Koch's postulates. The experiment was repeated one more time under similar conditions. To our knowledge, this is the first report of root rot caused by F. solani on wax gourd in the United States. Wax gourd is an important specialty crop in the southeastern United States and the occurrence of this disease needs to be taken into account in wax gourd production. References: (1) K. A. Abd-Elsalam et al. Afr. J. Biotechnol. 2:82, 2003. (2) C. Booth. Fusarium Laboratory Guide to the Identification of the Major Species. CMI, Kew, England, 1977. (3) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004.

scholarly journals First Report of False Rust Caused by Synchytrium minutum on Kudzu in Korea

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 358-358 ◽  
Author(s):  
H. Y. Yun ◽  
Y. H. Kim ◽  
T. Y. James
Keyword(s):  
New York ◽  
Biological Control ◽  
Control Strategies ◽  
The United States ◽  
Academic Press ◽  
First Report ◽  
Dark Orange ◽  
National University ◽  
Gyeonggi Province ◽  
Seoul National University

Kudzu (Pueraria montana var. lobata (Willd.) Maesen & S. Almeida) is a weedy, fabaceous vine that is native to and widely distributed in Asia where it is used for various medicinal purposes such as treating convulsions and fever (2). In the United States, especially the southeastern states, kudzu has become a problematic invasive species that overgrows nearly every substrate on which it occurs. Thus, biological control strategies for controlling this vine are of great interest (4). From October to November 2004, a disease of kudzu was observed in Gwangju and Pyeongtaek in Gyeonggi Province, Korea. The disease appeared on leaves and stems as numerous, discrete, small galls, which enlarged, becoming yellowish orange and eventually erupting into orange, pulverulent sori. Galls were scattered or gregarious, amphigenous, predominately hypophyllous, and sometimes formed along veins as well as on petioles and stems. Sori that formed from galls were solitary but sometimes became confluent, 0.1 to 1 mm in diameter, globose to subglobose, and orange to dark orange; walls were hyaline and thin. Sporangia were copious in sori, typically polyhedral due to compression or globose, 16 to 32 μm in diameter, with smooth, hyaline walls and orange contents. Zoospores were not observed during several failed attempts to germinate sporangia. On the basis of morphological descriptions and keys (3), the fungus was identified as Synchytrium minutum (Pat.) Gäum. (Chytridiomycota), the only species of Synchytrium known to occur on Pueraria (1,3). Comparison with specimens from China and New Guinea (BPI 794733 and BPI 1109528) confirmed this identification. Portions of the nLSU and nSSU rDNA from one of the two Korean specimens deposited as voucher material in the U.S. National Fungus Collections (BPI 880898 and BPI 880899) were sequenced (GenBank Accession Nos. HQ324138 and HQ324139), and a subsequent BLAST search against GenBank confirmed placement in the genus Synchytrium with 95% similarity to S. decipiens. S. minutum is widespread in Asia and Oceania and also has been reported from California (1,3). To our knowledge, this is the first report of S. minutum in Korea (1) and is noteworthy to those interested in biological control of kudzu because S. minutum may have potential in this regard. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , September, 2010. (2) H. S. Jung. M.S. thesis. Seoul National University, Seoul, Korea, 1997. (3) J. S. Karling. Synchytrium. Academic Press Inc., New York, NY, 1964. (4) M. A. Weaver et al. Biol. Control 50:150, 2009.

scholarly journals First Report of Xanthomonas Leaf Blight of Onion in California

Plant Disease ◽  
2002 ◽  
Vol 86 (3) ◽  
pp. 330-330 ◽  
Author(s):  
J. J. Nunez ◽  
R. L. Gilbertson ◽  
X. Meng ◽  
R. M. Davis
Keyword(s):  
Dna Sequences ◽  
Xanthomonas Campestris ◽  
Similarity Index ◽  
The United States ◽  
Leaf Blight ◽  
Yield Reduction ◽  
Bacterial Suspension ◽  
Fresh Market ◽  
First Report ◽  
Profile Similarity

In 2000 and 2001, severe leaf blight of fresh market onions occurred in several fields in the Antelope Valley of California, a high desert area located in northern Los Angeles County. In at least two fields, 70% of the canopy was affected, which resulted in an estimated yield reduction of over 50%. Both organically and conventionally grown onions were affected. Symptoms included numerous small chlorotic lesions that appeared first on older leaves. Lesions were often surrounded by water-soaked margins. As the season progressed, the lesions became elongated and necrotic. Entire leaf blades were often killed. The disease never progressed into the bulbs, but bulbs of infected plants never grew to full size. Yellow mucoid bacterial colonies were recovered on yeast extractdextrose-CaCO3 agar from symptomatic tissue. All isolates were gram-negative rods with single polar flagella. Two representative isolates were identified as Xanthomonas campestris based on their carbon utilization profile (similarity index of 0.784 and 0.850; Biolog, Hayward, CA), fatty acid profile (similarity index of 0.588; MIS-TSBA, version 4.10, MIDI Inc., Newark, DE), and 16S-23S intergenic spacer DNA sequences (98% sequence identify with strains of X. campestris). In greenhouse pathogenicity tests, eight white globe onion plants were inoculated with a bacterial suspension (106 CFU/ml) of each of the two isolates. Plants were inoculated by spraying the suspension on leaves lightly injured by rubbing with Carborundum or puncturing with needles dipped in the suspension. Controls were inoculated with water. All plants inoculated with the bacteria developed symptoms in 6 days. The bacterium was reisolated from all inoculated plants and confirmed as Xanthomonas. The trial was conducted twice. To our knowledge, this is the first report of Xanthomonas leaf blight of onion in California. In the United States, the disease has been reported in Texas and Colorado (1,2). References: 1. T. Isakeit et al. Plant Dis. 84:201, 2000. 2. H. F. Schwartz and K. Otto. Plant Dis. 84:922, 2000.

scholarly journals First Report of Meloidogyne enterolobii on Cotton and Soybean in North Carolina, United States

Plant Disease ◽  
2013 ◽  
Vol 97 (9) ◽  
pp. 1262-1262 ◽  
Author(s):  
W. M. Ye ◽  
S. R. Koenning ◽  
K. Zhuo ◽  
J. L. Liao
Keyword(s):  
United States ◽  
North Carolina ◽  
Dna Sequences ◽  
Natural Infection ◽  
Large Subunit ◽  
The United States ◽  
Infested Soil ◽  
First Report ◽  
Cotton Plants ◽  
Plant Pathol

Stunted cotton plants (Gossypium hirsutum L. cvs. PHY 375 WR and PHY 565 WR) from two separate fields near Goldsboro in Wayne County, North Carolina were collected by the NCDA&CS Agronomic Division nematode lab for nematode assay and identification in December 2011. The galls on cotton plants were very large in comparison with those commonly associated with Meloidogyne incognita Kofoid and White (Chitwood) infected cotton. In August 2012, the lab also received heavily galled roots of soybean (Glycine max (L.) Merr. cv. 7732) from Wayne and Johnston counties. Population densities of the 2nd-stage juveniles ranged from 150 to 3,800 per 500 cc soil. Female perineal patterns were similar to M. incognita, but PCR and DNA sequencing matched that of M. enterolobii Yang and Eisenback (4). DNA sequences of ribosomal DNA small subunit, internal transcribed spacer, large subunit domain 2 and 3, intergeneric spacer, RNA polymerase II large subunit, and histone gene H3, were found to be 100% homologous when comparing populations of M. enterolobii from North Carolina and China. Species identification was also confirmed using PCR by a species-specific SCAR primer set MK7-F/MK7-R (2). M. enterolobii Yang & Eisenback was described in 1983 from a population causing severe damage to pacara earpod tree (Enterolobium contortisiliquum (Vell.) Morong) in China (4). In 2004, M. mayaguensis Rammah & Hirschmann, a species described from Puerto Rico, was synonymized with M. enterolobii based on esterase phenotype and mitochondrial DNA sequence (3). M. enterolobii is considered to be a highly pathogenic species and has been reported from vegetables, ornamental plants, guava, and weeds in China, Africa, Central and South America, the Caribbean, and Florida in the United States (1,3,4). Of particular concern is its ability to develop on crop genotypes carrying root-knot-nematode resistance genes (Mi-1, Mh, Mir1, N, Tabasco, and Rk) in tobacco, tomato, soybean, potato, cowpea, sweet potato, and cotton. Consequently, this species was added to the European and Mediterranean Plant Protection Organization A2 Alert list in 2010. Two populations of M. enterolobii one from soybean and one from cotton were reared on tomato (Solanum lycopersicum L. var. lycopersicum) in a greenhouse setting. Eggs were extracted using NaOCl and inoculated, at a rate of 7,000 per 15-cm-diameter clay pot, into a sandy soil mixture (1:1 washed river sand and loamy sand). Tomato, peanut (Arachis hypogaea L.), cotton, watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai), pepper (Capsicum annuum L.), and root-knot-susceptible and -resistant tobacco (Nicotiana tabacum L. cvs. K326 and NC 70, respectively) were transplanted immediately into the infested soil with four replications. Root galls on the host differentials were evaluated after 90 days. Reproduction occurred on all hosts except for peanut, which is consistent with reports for M. enterolobii and M. incognita race 4 (4). Adult females from pepper plants used in the host differential test were sequenced on partial 18S and ITS1 region and confirmed to be M. enterlobii. To our knowledge, this is the first report of a natural infection of North Carolina field crops with M. enterolobii. References: (1) J. Brito et al. J. Nematol. 36:324, 2004. (2) M. S. Tigano et al. Plant Pathol. 59:1054, 2010. (3) J. Xu et al. Eur. J. Plant Pathol. 110:309, 2004. (4) B. Yang and J. D. Eisenback. J. Nematol. 15:381, 1983.

scholarly journals First Report of Leaf Spot Caused by Ramularia sphaeroidea on Vicia villosa var. glabrescens in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Min Shi ◽  
Yan Zhong Li
Keyword(s):  
Dna Sequences ◽  
Leaf Spot ◽  
Tween 80 ◽  
The United States ◽  
Diseased Plant ◽  
Post Inoculation ◽  
Distilled Water ◽  
Conidial Suspension ◽  
Vicia Villosa ◽  
First Report

Hairy vetch Vicia villosa Roth is widely grown in southwestern China for green manure and forage. In December 2019, a leaf disease occurred on 80% plants of V. villosa var. glabrescens in an eight-hectare field in Qujing(N 25°28′12″, E 103°36′22″), Yunnan Province, China. The disease leaves had irregular, brown to dark brown leaf spots with white mold. Twenty diseased leaves from five plants were randomly collected from the field. The leaf samples were sterilized with 75% ethanol for 30 s and 1% NaClO for 75 s, rinsed three times with sterile distilled water, surface water removed with sterile filter paper, and placed onto potato dextrose agar (PDA) for culture at 20oC. The obtained fungal isolates were purified by transferring 1 to 2 mm hyphal tips onto fresh PDA plates and cultured under the same temperature condition. The isolates grew slowly, at a rate of 0.7 mm/d at 20℃ for 4 weeks. A diseased plant specimen (accession MHLZU19326) and three isolates (accessions YN1931401, YN1931402, and YN1931403) were deposited in the Mycological Herbarium of Lanzhou University (MHLZU). Conidia from the PDA cultures were hyaline, spherical, smooth, aseptate, and measured 2.13 to 3.67 × 4.56 to 5.77 μm (n = 50). Conidiophores were hyaline, smooth, and straight. DNA of purified isolates was extracted and the nuclear ribosomal internal transcribed spacer (ITS), tef1-α, his3 and gapdh genes were amplified and sequenced with primers ITS1/ITS4 (White et al. 1990), EF1-728F/EF2 (Carbone and Kohn 1999;O’Donnell et al. 1998), CylH3F/CylH3R (Crous et al. 2004), and gpd1/gpd2 (Berbee et al. 1999), respectively. DNA sequences of isolates YN1931401, YN1931402, and YN1931403 were deposited in GenBank for the ITS (accessions MW092181, MW332205, and MW332206), tef1-α (MW448172 to MW448174), his3 (MW448175 to MW448177), and gapdh (MW448178 to MW448180). These sequences had the highest similarities with sequences of Ramularia sphaeroidea Sacc. in GenBank, 99%(514∕516, 515∕517, and 514∕517 bp) for ITS, 99% (402∕403, 403∕405, and 405∕405bp) for tef1-α, 99% (377∕378, 378∕378, and 376∕378bp) for his3, and 100% (558∕557, 557∕559 and 561∕565 bp) for gapdh . A phylogenetic tree generated with the sequences clustered the fungus closely with R. sphaeroidea. Infection experiments were carried out with 50 plants of V. villosa var. glabrescens in 10 pots. A conidial suspension of 1. 0 × 106 conidia/ml with 0.01% Tween 80 was prepared by adding sterile distilled water to the YN1931401 culture and scraping with a sterile scalpel. The leaves of 25 healthy plants were sprayed with the conidial suspension, and those of the 25 control plants were sprayed with sterile water. All plants were covered with clear polyethylene bags for 3 days to maintain high humidity and then grown in a greenhouse at diurnal cycles of 18℃ for 18h with light and 22℃ for 6 h in dark. Ten days post-inoculation, the inoculated plants exhibited brown lesions similar to the symptoms observed in the field (Fig. 1-F), whereas no symptoms appeared on the control plants. The same fungus was re-isolated and identified as described above. R. sphaeroidea has been reported on V. fabae and V. sativa in Ethiopia and Israel (Braun 1998), on various Vicia species including V. villosa in California, the United States (Koike et al. 2004) and on V. craccain China (Zhang et al. 2006), but to our knowledge, this is the first report of this fungus causing leaf spot on V. villosa in China.

Systematics of Hypnea (Cystocloniaceae, Rhodophyta) from coastal North Carolina, with a first report of Calliblepharis saidana from the United States Atlantic Coast

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jason T. Campbell ◽  
D. Wilson Freshwater ◽  
J. Craig Bailey
Keyword(s):  
United States ◽  
North Carolina ◽  
Dna Sequences ◽  
Atlantic Coast ◽  
The United States ◽  
Sensu Stricto ◽  
Western Hemisphere ◽  
Mitochondrial Cytochrome ◽  
First Report ◽  
Mitochondrial Cytochrome Oxidase

Abstract Complete and/or partial DNA sequences for the plastid-encoded rbcL gene and the 5′ end of the mitochondrial cytochrome oxidase I (COI-5P) gene were used to re-examine the systematics of Hypnea species (Cystocloniaceae, Rhodophyta) from North Carolina, USA. These data, combined with light microscopic observations, indicate that two species (Hypnea cryptica and H. musciformis sensu stricto) are present in nearshore waters of coastal North Carolina. Molecular and morphological analyses with topotype material of Hypnea volubilis from North Carolina offshore waters revealed that it and Calliblepharis saidana are conspecific. Hypnea volubilis is proposed as a heterotypic synonym of C. saidana. This is the first report of Calliblepharis from the United States Atlantic coast and only the second report from the western hemisphere.

scholarly journals First Report of Diplodia seriata Causing Pear Branch Canker Dieback in California

Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 688-688 ◽  
Author(s):  
R. A. Choudhury ◽  
P. Modi ◽  
J. Hanstad ◽  
R. Elkins ◽  
W. D. Gubler
Keyword(s):  
Dna Sequences ◽  
Fungal Growth ◽  
The United States ◽  
Economic Losses ◽  
Pathogenicity Test ◽  
Internal Transcribed Spacer Region ◽  
Diplodia Seriata ◽  
First Report ◽  
And Control ◽  
Branch Canker

California produces 26% of the United States pear crop on approximately 5,600 ha. A survey of seven northern California pear orchards (Pyrus communis cv. Bartlett) in summer 2010 revealed the presence of wedge-shaped cankers on 2- to 5-cm diameter branches, equating to 1- to 3-year-old wood. Many of the observed cankers occurred near pruning wounds, and there was decreased foliation on infected branches. Infected wood was surface disinfected with 95% ethanol and briefly flamed. After removing bark, small sections of diseased tissue were plated onto 4% potato dextrose agar (PDA) amended with 0.01% tetracycline and placed on the lab bench at 22°C until fungal growth emerged. Fungal colonies that were consistently isolated were transferred to fresh PDA using hyphal tip isolation. Fungal colonies were dark brown to gray with aerial mycelium and formed pycnidia after 15 days of incubation at 22°C. Conidia were brown, oval to oblong, and measured (16.5-) 20 to 24 (-26) × (7.5) 8.75 to 11 (-12.5) μm (n = 50). DNA from 14- to 21-day-old colonies was extracted and sequences of the rDNA internal transcribed spacer region and part of the β-tubulin gene were amplified using primers ITS4/ITS5 and Bt2a/Bt2b, respectively (2). The DNA sequences of fungal isolates from California showed 99 to 100% homology with the ex-type Diplodia seriata De Not. (1) CBS112555 deposited in GenBank. DNA sequences from three California isolates were submitted to GenBank with accession numbers KC937062, KC937065, KF481957, KF481598, KF481959, and KF481960. Pathogenicity tests were performed in March 2011 on 3-year-old Bartlett pear trees planted at an experimental farm in Davis, CA. A single, circular, 2-cm pruning wound at the top of the trunk was inoculated on each of three single-tree replications using 2-cm mycelial plugs from 14-day-old colonies growing on PDA. After inoculation, mycelial plugs were covered and sealed with Parafilm and aluminum foil for the duration of the trial. Three control trees were inoculated using sterile PDA plugs. Twelve months after inoculation, UCD103 and UCD105 were consistently re-isolated from the margin between necrotic and healthy tissue using the same methods described for the original isolation, and UCD102 was re-isolated in two out of three plants. The average lesion lengths of UCD102, UCD103, UCD105, and control plants were 12.5, 17.3, 23, and 1 mm, respectively. Control lesions were short and sterile, and seemed to be a physiological reaction from the plant. A second pathogenicity test was completed in 5 months beginning in June 2012. UCD105 was consistently re-isolated, and UCD102 and UCD103 were re-isolated in two out of three plants. The average lesion lengths for UCD102, UCD103, UCD105, and control plants were 2, 3, 5, and 1 mm, respectively. Compared to grapevine (Vitis vinifera), the pathogen grows more slowly in pear tissue under natural conditions. To our knowledge, this is the first report describing D. seriata as a causal agent of pear branch canker in California. Canker diseases can reduce the lifespan of perennial plants, ultimately leading to long term economic losses for growers (3). References: (1) A. J. L. Phillips et al. Fungal Diversity 25:141, 2007. (2) J. R. Urbez-Torres et al. Plant Dis. 90:1490, 2006. (3) J. R. Urbez-Torres and W. D. Gubler. Plant Dis. 93:584, 2009.

scholarly journals First Report of Neofabraea alba Causing Fruit Spot on Olive in North America

Plant Disease ◽  
2013 ◽  
Vol 97 (10) ◽  
pp. 1384-1384 ◽  
Author(s):  
S. Rooney-Latham ◽  
L. L. Gallegos ◽  
P. M. Vossen ◽  
W. D. Gubler
Keyword(s):  
United States ◽  
North America ◽  
Sodium Hypochlorite ◽  
Uv Light ◽  
The United States ◽  
Spore Suspension ◽  
United States Department ◽  
First Report ◽  
Control Fruit ◽  
Bull's Eye

Olive (Olea europaea) is a widely planted evergreen tree primarily grown for its oil, fruit for pickling, and landscape appeal in Mediterranean and temperate climates. California produces most of the olives grown in the United States; its industry was valued at $53 million in 2011 (4). In 2005 and 2008, fruit spotting occurred on coratina and picholine cultivars in two commercial orchards in Sonoma County. The spots were scattered, slightly sunken and brown, and surrounded by a green halo. Many of the spots were associated with lenticels. A slow to moderate growing, cream to rose-colored fungus was isolated from the spots onto potato dextrose agar (PDA) amended with 0.01% tetracycline hydrochloride. Sporulation was observed in vitro on PDA after 40 days under near-UV light. Macroconidia, produced from conidiomata, were hyaline, aseptate, cylindrical to fusiform-allantoid, slightly curved, and 17 to 27 × 2.5 to 3.5 μm (average 21.1 × 2.9 μm). Microconidia were aseptate, strongly curved, hyaline, and 14 to 18 × 0.75 to 1 μm (average 16.1 × 0.9 μm). rDNA sequences of the internal transcribed spacer (ITS) region of the isolate (GenBank KC751540), amplified using primers ITS1 and ITS4, were 99.8% identical to Neofabraea alba (E.J. Guthrie) Verkley (anamorph Phlyctema vagabunda) (=Gloeosporium olivae) (AF141190). Pathogenicity was tested on detached, green fruit (cv. frantoio). Olives were surface sterilized in 10% sodium hypochlorite for 5 min and air dried. Five olives were wounded with a needle and 10 μl spore suspension (105 spores/ml) was placed on each wound. An equal amount of spore suspension was placed on five unwounded olives. Water was also placed on wounded and unwounded olives to serve as a control. The olives were placed on racks in 22.5 × 30 cm crispers lined with wet paper towels and incubated at 23°C. After 21 days, the olives began to turn red. Olives wounded and inoculated with N. alba had a distinct green ring around the inoculation point where maturity was inhibited. Control olives uniformly turned red. After 35 days, wound-inoculated olives began to form a sunken, brown lesion at the inoculation point where aerial mycelium was visible. After 51 days, lesions were visibly sunken and immature conidiomata began to form in concentric rings giving a bull's eye-like appearance. Unwounded fruit exhibited uneven maturity and green spots associated with the lenticels throughout the experiment but did not develop sunken lesions. Control fruit showed no symptoms and ripened normally. After 56 days, fruit was surface sterilized in 10% sodium hypochlorite for 5 min and plated onto PDA. N. alba was isolated from the sunken and green areas of all of the wounded and unwounded fruit. No fungi grew from the control fruit. The experiment was repeated once with similar results. N. alba has been reported to cause an anthracnose disease on fruit and leaves of olives in Spain and Italy (1,2). In North America, N. alba causes a bull's eye rot on fruit of Malus and Pyrus spp. in the Pacific Northwest and coin canker of Fraxinus spp. in Michigan and Canada (3). To our knowledge, this is the first report of N. alba causing disease on olive in North America. References: (1) J. Del Maral de la Vega et al. Bol. San Veg. Plagas. 12:9. 1986. (2) S. Foschi. Annali. Sper. Agr., n.s. 9:911. 1955. (3) T. D. Gariepy et al. Can. J. Plant Pathol. 27:118. 2005. (4) United States Department of Agriculture, National Agricultural Statistics Service, California Field Office, California Agriculture Statistics, Crop Year 2011.

scholarly journals First Report of the Occurrence of Sweet potato leaf curl virus in Tall Morningglory (Ipomoea purpurea) in China

Plant Disease ◽  
2009 ◽  
Vol 93 (7) ◽  
pp. 764-764 ◽  
Author(s):  
C. X. Yang ◽  
Z. J. Wu ◽  
L. H. Xie
Keyword(s):  
Sweet Potato ◽  
Dna Sequences ◽  
Ipomoea Batatas ◽  
Rolling Circle Amplification ◽  
The United States ◽  
Natural Occurrence ◽  
Potato Leaf ◽  
First Report ◽  
Leaf Curl Virus ◽  
Leaf Curl

Natural occurrence of Sweet potato leaf curl virus (SPLCV) has been reported in Ipomoea batatas (sweet potato, Convolvulaceae) or I. indica (Convolvulaceae) in several countries including the United States, Sicily, and China (1–3). In September of 2007, while collecting samples showing begomovirus-like symptoms in the Chinese province of Fujian, we observed tall morningglory (I. purpurea (L.) Roth, also known as Pharbitis purpurea (L.) Voigt), plants with slightly yellow mosaic and crinkled leaves. Total DNA was extracted from leaves of these plants and tested by rolling circle amplification (4). Amplification products were digested by the restriction enzyme BamHI for 30 min. Restriction products (2.8 kb) were then cloned into pMD18T vector (Takara Biotechnology, China) and sequenced. Comparison of complete DNA sequences by Clustal V analysis revealed that these samples were infected by the same virus, and an isolate denoted F-p1 was selected for further sequence analysis. F-p1 was 2,828 nucleotides, with the typical genomic organization of begomoviral DNA-A (GenBank Accession No. FJ515896). F-p1 was compared with the DNA sequences available in the NCBI database using BLAST. The whole DNA sequence showed the highest nucleotide sequence identity (92.1%) with an isolate of SPLCV (GenBank Accession No. FJ176701) from Jiangsu Province of China. The result confirmed that the samples from the symptomatic tall morningglory were infected by SPLCV. To our knowledge, this is the first report of the natural occurrence of SPLCV in I. purpurea, a common weed species in China. References: (1). P. Lotrakul et al. Plant Dis. 82:1253, 1998. (2). R. W. Briddon et al. Plant Pathol. 55:286, 2006. (3) Y. S. Luan et al. Virus Genes 35:379, 2007. (4) D. Haible et al. J. Virol. Methods 135:9, 2006.

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