First Report of Botryosphaeria iberica Associated with Dieback and Tree Mortality of Monterey Cypress (Cupressus macrocarpa) in Algeria

Stem cankers and branches showing bark discoloration, fissuring, resin exudation leading to dieback, crown wilting, and tree mortality have been observed since late spring 2008 on 40-year-old Cupressus macrocarpa (Hartw.) trees planted in forests mixed with Juniperus oxycedrus L. and Acer monspessulanum L. in Taffet, near Ain Abbessa, in the district of Bougaa, Algeria (36°18′57″N; 05°06′33″E; 1,400 m elevation). In 2010, approximately 60% of the C. macrocarpa trees were diseased. For fungal isolations, cankered branches were surface sterilized with ethanol. After removal of the outer bark, fragments of necrotic inner bark taken from the margin of cankers were plated on potato dextrose agar (PDA). Most of the colonies were identified as Botryosphaeria iberica (Phillips, Luque & Alves) based on comparison of morphological traits and DNA sequences with known isolates of the fungus (1). Pestalotiopsis funerea colonies were also obtained, although with less frequency. B. iberica colonies on PDA were dark green with aerial mycelium and optimum growth at 25°C. Pycnidia were produced after 3 weeks of incubation at 20°C under a 12-h near UV light photoperiod on water agar amended with autoclaved cypress seeds. Conidia were brown, one-septate, oval to oblong, and 24.2 (20.1 to 27.4) × 11.2 μm (8.8 to 14.1) (n= 50). An isolate was deposited at the Centralbureau voor Schimmelculture as CBS 130984. DNA was extracted from freeze-dried mycelium and amplified using primers ITS1 and ITS4. The amplified DNA sequence of B. iberica isolate CBS 130984 from Algeria (GenBank Accession No. JN836991) showed 100% homology with sequences of B. iberica isolates obtained from dead and cankered bark of oaks from Spain and Italy (GenBank Accession Nos. AY573216, AY573214, AY573213, AY573210, AY573202, and AY573201). Stem inoculations were performed in the greenhouse on 10 4-year-old, grafted plants of C. macrocarpa growing in 5-liter pots using isolate CBS 130984. A 3-mm plug taken from the margin of a colony grown on PDA for 1 week was inserted in a circular wound of the same size made in the bark with a cork borer where the stem diameter was approximately 1 cm. Inoculations were repeated in June 2010 and June 2011. Five months after inoculations, small rounded to elongated lesions (1.0 to 2.5 cm long), sometimes with resin exuding cracks, were visible on all inoculated stems. Control trees, inoculated with sterile PDA plugs, showed no canker development. B. iberica was successfully reisolated from the necrotic bark surrounding the inoculation sites. No significant differences in canker size were observed between the two replicated experiments. Some Botryosphaeria species that are found on a variety of hosts are also known to cause cankers and dieback of cypress; among these are B. stewensii, B. obtusa, B. dothidea, and B. ribis, often acting as weak pathogens (2,3). Considered weakly virulent in causing dieback of grapevine (4) and, to our knowledge, reported here for the first time on Cupressaceae, B. iberica caused cankers and dieback of C. macrocarpa trees that had probably been weakened by repeated drought events occurring in Algeria during the last 10 years. References: (1) A. Phillips et al. Mycologia 97:513, 2005. (2) E. Punithalingam and J. M. Waller. IMI Descriptions of Fungi and Bacteria 40, Sheet 394, 1973; (3) E. Punithalingam and P. Holliday. IMI Descriptions of Fungi and Bacteria. 40, Sheet 395, 1973; (4) R. Úrbez-Torres et al. Plant Dis. 93:584, 2009.

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First Report of Botryosphaeria iberica and B. viticola Associated with Grapevine Decline in California

Plant Disease ◽

10.1094/pdis-91-6-0772c ◽

2007 ◽

Vol 91 (6) ◽

pp. 772-772 ◽

Cited By ~ 27

Author(s):

J. R. Úrbez-Torres ◽

W. D. Gubler ◽

J. Luque

Keyword(s):

Dna Sequences ◽

Aerial Mycelium ◽

Width Ratio ◽

Optimum Growth ◽

Internal Transcribed Spacer Region ◽

First Report ◽

Grapevine Decline ◽

San Luis ◽

Length Width ◽

Dark Green

Grapevine decline symptoms in California include dead spurs and cordon and trunk dieback due to canker formation in the vascular tissue. Seven Botryosphaeria spp. are known to be associated with grapevine cankers in California, viz. Botryosphaeria australis, B. dothidea, B. lutea, B. obtusa, B. parva, B. rhodina, and B. stevensii (3). Recently, B. iberica and B. viticola also were isolated from grapevine cankers in a field survey that was conducted throughout California. Identification was based on morphological comparisons along with DNA analyses with previously identified isolates from Spain (1,2): B. iberica (CBS115035, ex-type) and B. viticola (CBS117006 and CBS117009, ex-type). DNA sequences of the rDNA internal transcribed spacer region (ITSI-5.8S-ITS2), part of the β-tubulin gene (BT2), and part of the translation elongation factor 1-α gene (EF1-α) from B. iberica and B. viticola isolates from California were amplified using primers ITS4/ITS5, Bt2a/Bt2b, and EF-728F/EF-986R, respectively. All DNA sequences of B. iberica and B. viticola from California showed 99 to 100% homology with those previously identified and deposited in GenBank. B. iberica, isolated from grapevine cankers from San Luis Obispo County (central coast), formed colonies on potato dextrose agar (PDA) that were dark green with aerial mycelium, optimum growth at 20 to 25°C, and formed pycnidia after 15 days of incubation at 25°C. Conidia were brown, one-septate, oblong to ovoid with a rounded apex, and measured (20.1-) 22.5 to 23.5 (-27.1) × (8.1) 9.3 to 9.8 (-11.2) μm, length/width ratio = 2.4 (n = 60). B. viticola, isolated from grapevine cankers in Sonoma (north coast), San Luis Obispo, Santa Barbara (south coast), Riverside (southern California), and Yolo (Sacramento Valley) counties, formed colonies on PDA that were dark green to grayish with aerial mycelium, optimum growth at 25°C, and formed pycnidia after 2 weeks. Conidia were brown, one-septate, oval to oblong, and measured (16.6-) 19.3 to 20.3 (-23.5) × (8.1) 9.3 to 9.6 (-11.1) μm, length/width ratio = 2.1 (n = 60). Two isolates of each species were used to complete pathogenicity tests (B. iberica: ATCC MYA-4110, ATCC MYA-4111; B. viticola: ATCC MYA-4115, ATCC MYA-4116). Ten fresh pruning wounds on 15-year-old cv. Zinfandel vines were inoculated per isolate using 50 μl of a 5 × 106 conidia per ml suspension. Twenty control pruning wounds were inoculated with the same amount of sterile water. Twelve months after inoculation, all wood inoculated with B. iberica and B. viticola showed internal necrosis extending 35 to 50 and 30 to 35 mm from the point of inoculation, respectively. Necrosis and extent of vascular discoloration in infected wounds was significantly greater (P < 0.05) than in control inoculations (6.5 mm). B. iberica and B. viticola were reisolated from the necrotic region surrounding all inoculation sites. Representative isolates of B. iberica and B. viticola from California were deposited at the American Type Culture Collection (B. iberica: MYA-4110, MYA-4111; B. viticola: MYA-4112 to MYA-4116). Sequences from the studied DNA regions of all isolates were deposited at GenBank. To our knowledge, this is the first report implicating either species as a cause of grapevine decline in California and B. iberica as a pathogen of Vitis vinifera anywhere in the world. References: (1) J. Luque et al. Mycologia 97:1111, 2005. (2) A. J. L. Phillips et al. Mycologia 97:513, 2005. (3) J. R. Úrbez-Torres et al. Plant Dis. 90:1490, 2006.

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First Report of Lasiodiplodia theobromae Causing Dieback of Aquilaria sinensis in Taiwan

Plant Disease ◽

10.1094/pdis-10-12-0998-pdn ◽

2013 ◽

Vol 97 (5) ◽

pp. 690-690 ◽

Cited By ~ 2

Author(s):

M.-C. Fan ◽

H.-C. Yeh ◽

C.-F. Hong

Keyword(s):

Uv Light ◽

Aerial Mycelium ◽

Molecular Characteristics ◽

Width Ratio ◽

Sodium Hypochlorite Solution ◽

Aquilaria Sinensis ◽

Lasiodiplodia Theobromae ◽

First Report ◽

Tree Survival ◽

Pathogenicity Tests

Incense trees (Aquilaria sinensis (Lour.) Gilg) belong to a plant family used for alternative medicine in China and the production of wood. In the summer of 2012, at a nursery in Niaosong district, Kaohsiung City, Taiwan, more than 30% of a total of 400 incense trees had dieback symptoms on twigs with leaves attached, leading to eventual death of the entire plant. Symptomatic twigs and trunk pieces from six trees were collected and discolored tissues were excised, surface sterilized in 0.5% sodium hypochlorite solution, rinsed in sterilized distilled water, dried on sterilized filter paper, and then placed in petri dishes containing 2% water agar (WA). The dishes were incubated at room temperature for 1 to 2 days to obtain fungal strains from diseased tissues. The hyphal tips from developing fungal colonies were transferred to potato dextrose agar (PDA, Difco) dishes and placed under UV light (12 h/day) at 30°C. The purified colonies were used as inoculum in the pathogenicity tests. Pathogenicity tests were performed on 2-month-old A. sinensis seedlings, each treatment had three plants. Each plant was wounded by removing bark of the twigs with a disinfected scalpel enough to place a mycelium plug (about 5 × 10 mm2) of 7-day-old fungal isolate on the wound. The inoculated area was wrapped with a wet paper towel and Parafilm. Control plants were treated with PDA plugs. The symptoms described above were observed on inoculated plants 4 to 8 days after inoculation whereas control plants did not show symptoms. Diseased twigs were cut and placed in a moist chamber 21 days after inoculation and conidia oozing from pycnidia were observed. The same fungal pathogen was reisolated from inoculated plants, but not from the control. To identify the pathogen, the fungus was cultured as described above. The colonies were initially white with green to gray aerial mycelium after 5 to 6 days and eventually turned darker. Immature conidia were hyaline and one-celled, but mature conidia were dark brown, two-celled, thin-walled, and oval-shaped with longitudinal striations. The average size of 100 conidia was 25.23 ± 1.97 × 13.09 ± 0.99 μm with a length/width ratio of 1.92. For the molecular identification, the internal transcribed spacer (ITS) region of ribosomal DNA was PCR amplified with primers ITS1 and ITS4 (2) and sequenced. The sequences were deposited in GenBank (Accession No. JX945583) and showed 99% identity to Lasiodiplodia theobromae (HM346871, GQ469929, and HQ315840). Hence, both morphological and molecular characteristics confirmed the pathogen as L. theobromae (Pat.) Griffon & Maubl (1). To the best of our knowledge, this is the first report of L. theobromae causing dieback on Incense tree. This disease threatens tree survival and may decrease the income of growers. References: (1) W. H. Ko et al. Plant Dis. 88:1383, 2004. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, New York, 1990.

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First Report of Fusarium equiseti Associated on Pecan (Carya illinoinensis) Seeds in Brazil

Plant Disease ◽

10.1094/pdis-09-13-0976-pdn ◽

2014 ◽

Vol 98 (6) ◽

pp. 847-847 ◽

Cited By ~ 7

Author(s):

M. Lazarotto ◽

M. F. B. Muniz ◽

R. F. dos Santos ◽

E. Blume ◽

R. Harakawa ◽

...

Keyword(s):

Dna Sequences ◽

Root Rot ◽

Consensus Sequence ◽

Elongation Factor ◽

Aerial Mycelium ◽

Carya Illinoinensis ◽

Pathogenicity Test ◽

Fusarium Equiseti ◽

Genus Fusarium ◽

Fusarium Sp

Pecan [Carya illinoinensis (Wangenh.) K. Koch] is an important producing nut tree that has been intensively cultivated in the state of Rio Grande do Sul (Brazil) in recent decades. This species is commonly grown in association with other crops and more often with cattle or sheep. An elevated incidence of the fungal genus Fusarium was observed during a quality control seed assay of pecan seeds obtained from orchards in the city of Anta Gorda (28°53′54.7″ S, 52°01′59.9″ W). Concomitantly, seedlings of this species, cultivated in a nursery, showed foliar necrosis, wilt, and root rot. The fungus was thereafter isolated from the seeds (from original seeds lots) and subcultured from single spores. Cultures were purified in order to perform pathogenicity tests. The isolated Fusarium sp. was increased on autoclaved wet corn kernels that were incubated for 14 days (1), and then were mixed with commercial substrate (sphagnum turf, expanded vermiculite, dolomitic limestone, gypsum, and NPK fertilizer) in plastic trays (capacity 7 L), with drainage holes. Twenty seeds were sowed and 90 days later, evaluations were undertaken. Forty percent of the seedlings presented symptoms, i.e., foliar necrosis and wilt owing to root rot. Fusarium sp. was re-isolated from the affected roots by transferring hyphal tips to potato dextrose agar (PDA) and carnation leaf agar (CLA) medium in petri dishes in order to identify the species morphologically. On PDA, the colony pigmentation was yellowish brown and the aerial mycelium was whitish to peach; macroconidia were relatively long and narrow (31.75 × 4.02 μm), with 5 septa on average, and whip-like bent apical cells (2). Chlamydospores were not observed on PDA or CLA. Primer pairs ITS1 and ITS4 (3) and EF1-T and EF1-1567R (4) were employed to amplify the internal transcribed spacer (ITS) and elongation factor-1α (TEF 1-α) regions, respectively. The resulting DNA sequences showed 99% for ITS and 98% for TEF 1-α similarity with Fusarium equiseti (Corda) Sacc. and phylogenetic analysis grouped it with sequences of this species. The consensus sequence was submitted to GenBank and received the accession numbers KC810063 (ITS) and KF601580 (TEF 1-α). The pathogen was re-isolated on PDA and CLA substrate in order to complete Koch's postulates. The pathogenicity test was repeated with the same conditions described before and the results were confirmed. No symptoms were observed on the control seedlings. This species is considered a weak parasite (2); however, it has been reported causing wilt in Coffea arabica in Brazil (5). This pathogen could cause serious damage and high losses to seedling in commercial nurseries. Besides that, it could also carry the disease to the field causing further damage on established plants. To our knowledge, this is the first to report of F. equiseti causing foliar necrosis and wilt on C. illinoinensis in Brazil. References: (1) L. H. Klingelfuss et al. Fitopatol. Brasil. 32:1, 2007. (2) W. Gerlach and H. Nirenberg. The Genus Fusarium – a Pictorial Atlas. Biologische Bundesanstalt für Land- und Forstwirtschaft, Braunschweig, Germany, 1982. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications, Academic Press, San Diego, CA, 1990. (4) S. A. Rehner and E. A. Buckley. Mycologia 97:84, 2005. (5) L. H. Pfenning and M. F. Martins. Page 283 in: Simpósio de Pesquisa dos Cafés do Brasil, 2000.

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Two new species of Hygrophorus from temperate Himalayan Oak forests of Pakistan

MycoKeys ◽

10.3897/mycokeys.56.30280 ◽

2019 ◽

Vol 56 ◽

pp. 33-47 ◽

Cited By ~ 2

Author(s):

Arooj Naseer ◽

Abdul Nasir Khalid ◽

Rosanne Healy ◽

Matthew E. Smith

Keyword(s):

New Species ◽

Dna Sequences ◽

Large Subunit ◽

Its Region ◽

Morphological Characters ◽

Nuclear Ribosomal Dna ◽

Oak Forests ◽

Rdna Genes ◽

Two New Species ◽

Dark Green

The genus Hygrophorus is poorly studied from Asia. From Pakistan, only one species has been reported so far. Two new species in the genus have been collected from Himalayan oak forests of Pakistan. Hygrophorusalboflavescens (section Pudorini, subgenus Colorati) is characterised by its pure white, centrally depressed pileus, occurrence of white stipe with yellow patches at lower half and broader (4.98 μm) basidiospores. Hygrophorusscabrellus (section Hygrophorus, subgenus Hygrophorus) is characterised by its yellowish-green stipe with white apex that has fine scales on the entire stipe, an off-white pileus with dark green and greyish fibrils, ovoid to ellipsoid basidiospores and clavate 4-spored basidia. Macro- and micromorphological descriptions have revealed that both these taxa are not yet described. Phylogenetic estimation based on DNA sequences from the internal transcribed spacer (ITS) region and large subunit (LSU) of the nuclear ribosomal DNA (rDNA) genes, is congruent with the morphological characters that help to delimit these as new species of Hygrophorus. Allied taxa are also compared.

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Occurrence of Botryosphaeria obtusa, B. dothidea, and B. parva Associated with Grapevine Trunk Diseases in Castilla y León Region, Spain

Plant Disease ◽

10.1094/pd-90-0835a ◽

2006 ◽

Vol 90 (6) ◽

pp. 835-835 ◽

Cited By ~ 15

Author(s):

J. R. Úrbez-Torres ◽

W. D. Gubler ◽

H. Peláez ◽

Y. Santiago ◽

C. Martín ◽

...

Keyword(s):

Morphological Characteristics ◽

Aerial Mycelium ◽

Common Disease ◽

Internal Transcribed Spacer Region ◽

Grapevine Trunk Diseases ◽

Eutypa Dieback ◽

Castilla Y Leon ◽

Pure Cultures ◽

Dark Green ◽

Production Areas

Between 2000 and 2004, 176 vineyards were surveyed for disease symptoms throughout the main grapevine-production areas of Bierzo, Cigales, Ribera del Duero, Rueda, and Toro in the Castilla y León region of Spain. Symptoms resembling Eutypa dieback, such as stunted chlorotic shoots, deformed leaves with necrotic areas, and typical wedge-shaped cankers in the wood, were observed in 80% of surveyed vineyards. The second most common disease observed was esca. The mild form of esca, interveinal chlorosis or reddened patterns on the leaves, was observed in 35% of surveyed vineyards. Severe esca symptoms that include sudden defoliation of some or all parts of the vine followed by shriveling of fruit clusters were observed in vineyards during very hot and dry summer periods. Wood from vines with esca was yellowish, soft, and often partially or completely surrounded by necrotic wood. Black vascular streaking in the wood was also observed in some vines with esca. Samples of wood from vines with symptoms of Eutypa dieback or esca were collected from different cultivars (Tempranillo, Cabernet Sauvignon, Mencía, Garnacha, Viura, and Verdejo). Small pieces of symptomatic wood were placed on 4% potato dextrose agar amended with tetracycline hydrochloride (0.01%) (PDA-tet) and incubated at room temperature. Pure cultures were obtained by excising hyphal tips and transferring to PDA-tet. Species of Botryosphaeria were most frequently isolated from wedge-shaped cankers as well as from wood with necrosis or black vascular streaking. Botryosphaeria spp. also were isolated from the soft yellowish wood, however, Fomitiporia punctata, Stereum hirsutum, and Phaeoacremonium spp. were the most common fungi associated with this symptom. On the basis of morphological characteristics in culture (1), three species were isolated (B. obtusa, B. dothidea, and B. parva). Colonies of B. obtusa were green to dark green with moderate aerial mycelium. Pycnidia developed after 6 days and conidia (n = 50) measured 19 to 27 × 9 to 17 μm and were hyaline and light brown, becoming dark brown when mature, mostly aseptate, and rounded in shape. Colonies of B. dothidea were white, becoming dark green with age and with copious aerial mycelium. Pycnidia started to develop after 10 days, and conidia measured 17 to 31 × 4 to 8 μm, were hyaline, aseptate, and fusiform in shape. Colonies of B. parva were similar in appearance to those of B. dothidea but pycnidia developed after 5 weeks. Conidia measured 11 to 21 × 4 to 9 μm, were hyaline when immature, becoming light brown with two septa with age, and ellipsoidal in shape. Identity of the three Botryosphaeria species was confirmed by comparing morphology with growth of the following identified California isolates: B. obtusa (UCD352Mo and UCD666Na), B. dothidea (UCD1066So), and B. parva (UCD642So) and by comparing sequences of the internal transcribed spacer region (ITSI-5.8S-ITS2) rDNA, and a partial sequence of the β-tubulin gene (BT2) of our isolates with those of previously identified and sequenced isolates deposited in GenBank. Sequences of B. obtusa (UCD343Spa, UCD461Spa, UCD468Spa, and UCD621Spa), B. dothidea (UCD303Spa), and B. parva (UCD577Spa and UCD578Spa) were deposited in GenBank. To our knowledge, this is the first report of B. obtusa, B. dothidea, and B. parva on grapevines in the Castilla y León region in Spain. Reference: (1) A. J. L. Phillips. Phytopathol. Mediterr. 41:3, 2002.

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First Report of Dieback on Hybrid Rhododendrons Caused by Neofusicoccum luteum and N. parvum in Spain

Plant Disease ◽

10.1094/pdis-10-10-0723 ◽

2011 ◽

Vol 95 (2) ◽

pp. 221-221 ◽

Cited By ~ 6

Author(s):

C. Pintos Varela ◽

V. Redondo Fernández ◽

J. P. Mansilla Vázquez ◽

O. Aguín Casal

Keyword(s):

Dna Sequences ◽

Uv Light ◽

Morphological Characteristics ◽

Phytophthora Ramorum ◽

Malt Extract ◽

First Report ◽

Agar Plug ◽

Thin Walled ◽

Neofusicoccum Luteum

During the conducting of Phytophthora ramorum surveys at Galician public parks (northwestern Spain) in 2010, established Rhododendron spp. plants were observed to be exhibiting leaf spots and necrosis, shoot blight, and cankers and dieback of shoots and branches. Branches and leaves of affected rhododendrons contained pseudothecia with bitunicate asci and hyaline pseudoparaphyses, and pycnidia were observed within the same stromatic masses. Symptomatic samples were disinfested in 0.5% sodium hypochlorite for 3 min. Tissues were cut from the margin of lesions, placed onto malt extract agar amended with streptomycin (25 μg ml–1), and incubated at 25°C in the dark. Cultures displaying morphological characteristics associated with Botryosphaeriaceae species were subcultured on 2% water agar with sterilized Pinus pinaster needles as a substrate and incubated at 25°C under near-UV light to encourage pycnidial production (1). Single conidial cultures gave rise to two distinct colonies on potato dextrose agar (PDA) at 25°C. In type 1, isolates produced a sparse, aerial mycelium and a characteristic yellow pigment that was more intense after 3 days, thereafter becoming violaceous and gradually turning dark gray. Growth occurred in the range of 4 to 38°C with an optimum at 29°C. Conidia were hyaline, fusiform, aseptate, thin walled, and averaged 21.1 (14.3 to 25.0) × 5.7 (4.3 to 6.8) μm with a length/width (L/W) ratio of 3.7 ± 0.4 (n = 100). On the basis of these characteristics, isolates were identified as Neofusicoccum luteum (1,3). Colonies of type 2 produced a dense, white-to-yellowish mycelium that rapidly became gray followed by marked diurnal zonation. Mycelial growth occurred in the range of 6 to 38°C with an optimum at 29 to 30°C. Conidia were hyaline, elliptical or fusiform, aseptate, thin walled, and averaging 18.3 (14.1 to 20.7) × 5.8 (4.6 to 7.0) μm with a L/W ratio of 3.2 ± 0.4 (n = 100). These isolates were identified as N. parvum (1,2). Identity was confirmed by DNA sequences analysis of internal transcribed spacer (ITS) regions. Comparison of the sequences of type 1 and 2 showed 100% homology with N. luteum and N. parvum (GenBank Accession Nos. EU673311 and GU251146, respectively). Representative sequences were deposited at GenBank (Accession Nos. HQ197352 and HQ197351). Pathogenicity of each isolate of N. luteum and N. parvum was confirmed by inoculating four 3-year-old Rhododendron spp. seedlings grown in pots. Shallow cuts were made in three branches of each plant. A colonized 6-mm agar plug, removed from the margin of an actively growing colony, was inserted beneath the flap and sealed with Parafilm. Four control seedlings received only sterile PDA agar plugs. Plants were maintained at 26°C and 70% humidity for 21 days. Inoculated plants began showing symptoms after 3 days. Necrosis progressed quickly and bidirectionally from the wound, resulting in death of leaves and wilting of shoots. N. luteum and N. parvum were reisolated from all inoculated plants but not from the controls. To our knowledge, this is the first report of N. luteum and N. parvum on Rhododendron spp. in Spain. References: (1) P. W. Crous et al. Stud. Mycol. 55:235, 2006. (2) S. R. Pennycook et al. Mycotaxon 24:445, 1985. (3) A .J. L. Phillips et al. Sydowia 54:59, 2002.

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First Report of Fusarium oxysporum f. sp. lactucae Race 1 Causing Fusarium Wilt of Lettuce in Norway

Plant Disease ◽

10.1094/pdis-01-21-0134-pdn ◽

2021 ◽

Author(s):

Maria Luz Herrero ◽

Nina Elisabeth Nagy ◽

Halvor Solheim

Keyword(s):

Costa Rica ◽

Fusarium Oxysporum ◽

Vascular Tissue ◽

Uv Light ◽

Elongation Factor ◽

Aerial Mycelium ◽

Light Cycle ◽

Single Spore ◽

Fungal Isolates ◽

Race 1

Lettuce (Lactuca sativa L.) is produced in Norway both in field and greenhouses. In Norway, greenhouse lettuce is one of the most important vegetables grown year-round. In winter 2018, wilting symptoms were observed on soil-grown lettuce of the cultivar Frillice in a greenhouse in south east Norway (Buskerud county). Affected plants showed stunted growth, wilting of outer leaves, and brownish discoloration of vascular tissues of taproots and crowns. According to the producer, the disease led to an estimated 10% of yield losses. Fungal isolates were obtained from crowns and roots of diseased plants collected from the greenhouse in 2018 and 2019. Two single spore isolates, 231274 from 2018 and 231725 from 2019, were used in further studies. The isolates were incubated on synthetic nutrient-poor agar (SNA) at 18-20 ⁰C, and a 12 hours dark, 12 hours UV light cycle. Isolate 231274 produced abundant macro- and microconidia characteristics of Fusarium oxysporum while macroconidia were never observed in isolate 231725. On potato dextrose agar (PDA), colonies of isolate 231274 were purple in color and colonies of isolate 231725 were pinkish with abundant aerial mycelium. For PCR-assay, DNA from mycelia was extracted using Easy-DNA kit (Invitrogen). A portion of the translation elongation factor 1-α (EF1-α) gene was amplified using primers F-728F (Carbone and Kohn. 1999) and EF2 (O'Donnell et al. 1998) as described by Aas et al. 2018. Blast analysis of both sequences (accession no. MW316853 for 231274 and MW316854 for 231275) obtained a 99% homology with the sequence of Fusarium oxysporum f.sp. lactucae (FOL) race 1 strain S1 (accession no. DQ837657)(Mbofung et al. 2007). Both isolates were identified as race 1 by using specific primers Hani3’ and Hanilatt3rev (Pasquali et al. 2007) as described by Cabral et al. 2014. To complete Koch’s postulate, lettuce plants of the cultivar Frillice were used. Race identity was confirmed using the differential lettuce cultivars Costa Rica No.4 (resistant to FOL race 1), Banchu Red Fire (resistant to FOL races 2 and 4) and Romana Romabella (resistant to FOL races 1 and 2) (Gilardi et al. 2017) provided by the breeding company Rijk Zwaan (De Lier, The Netherlands). For inoculation, roots of six 2-weeks old seedlings per cultivar were dipped in a spore suspension (1 x 106 CFU/ml) for 1 min, while controls were dipped in distilled water. Seedlings were planted in 250 ml pots containing fertilized potting substrate, and were placed in a greenhouse with temperature ranging from 15 to 35 ⁰C and an average of 23 ⁰C. After 10 days reduced growth was observed in cultivars Frillice and Banchu Red Fire for both fungal isolates. After 25 days wilting was observed in both cultivars. Affected plants presented discoloration of vascular tissue. No difference in growth was observed between cultivars Romana Romabella and Costa Rica No. 4 and their respective controls. FOL was re-isolated from all inoculated cultivars but not from controls. The colony patterns of the recovered isolates were the same than those of the isolates used for inoculation. These results confirm that the isolate belongs to race 1. Greenhouse lettuce in Norway is mainly produced in hydroponics. FOL is here reported to cause damages in soil- grown lettuce. Nevertheless FOL in hydroponic systems has been reported in Japan (Fujinaga et al. 2003) and Thailand (Thongkamngam and Jaenaksorn 2017). Thus, the possibility of infections in hydroponics remain a big concern for lettuce production in Norway.

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Preliminary Quantification of Phytochemicals in Methanolic Extract of Rosmarinus officinalis L Using HPTLC

International Journal of Pharmaceutical Sciences Review and Research ◽

10.47583/ijpsrr.2021.v70i01.030 ◽

2021 ◽

Vol 70 (1) ◽

Author(s):

Pathania Singh Mamta ◽

Singh Hitender ◽

Guleria Puspha ◽

Sapna Sapna ◽

Bhardwaj Payal ◽

...

Keyword(s):

Uv Light ◽

Chemical Constituents ◽

Natural Habitat ◽

Rosmarinus Officinalis ◽

Perennial Herb ◽

Food Preservative ◽

The Family ◽

Botanical Description ◽

Rosmarinus Officinalis L ◽

Dark Green

Rosmarinus officinalis L. commonly known as Rosemary belong to the family Lamiaceae. It is an aromatic herb which is hardy, dense and evergreen in natural habitat. It is one of the medicinal plants which is cultivated around the world for its medicinal, therapeutic purpose and is used as condiment and food preservative. It is one of the oldest Mediterranean shrub having strong, pungent aroma having dark green and elongated leaves with white or purple flowers. It is a perennial herb reaching 100 to 210 cm in height having pointed and hairy, resinous dark green leaves with lower white surface. The present study review about macroscopical/botanical description of Rosmarinus officinalis L. and its methanolic extraction analysis for preliminary quantification of chemical constituents by visualizing TLC plate under different wavelength of UV light i.e., 255nm, 366nm and 566nm to get chromatograph by HPTLC.

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Ottelia fengshanensis, a new bisexual species of Ottelia (Hydrocharitaceae) from southwestern China

PhytoKeys ◽

10.3897/phytokeys.135.38531 ◽

2019 ◽

Vol 135 ◽

pp. 1-10

Author(s):

Zhi-Zhong Li ◽

Shuang Wu ◽

Chun-Yu Zhou ◽

Yan Liu ◽

Guang-Wan Hu ◽

...

Keyword(s):

New Species ◽

Dna Sequences ◽

Species Delimitation ◽

Southwest China ◽

Morphological Features ◽

Bisexual Species ◽

Molecular Phylogenetic ◽

Dark Green ◽

Close Relatives ◽

A New Species

Ottelia fengshanensis, a new species (Hydrocharitaceae) from southwest China is here described and illustrated. Comparing its morphological features to putative close relatives O. guanyangensis, it has 3–4 flowers (vs. 2–5) each spathe, hexagonal-cylindric fruit, white styles (vs. yellow), green leaves (vs. dark green) and fruit tiny winged (vs. winged obviously). Molecular phylogenetic investigation of four DNA sequences (ITS, rbcL, trnK5’ intron and trnS-trnG) and the Poisson Tree Processes model for species delimitation (PTP) analysis, further resolves O. fengshanensis as a new species that is close to O. guanyangensis with distinct support.

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Predisposition of Melaleuca (Melaleuca quinquenervia) to Invasion by the Potential Biological Control Agent Botryosphaeria ribis

Weed Science ◽

10.1017/s0043174500094418 ◽

1996 ◽

Vol 44 (3) ◽

pp. 603-608 ◽

Cited By ~ 4

Author(s):

Min B. Rayachhetry ◽

George M. Blakeslee ◽

Ted D. Center

Keyword(s):

Biological Control ◽

Low Temperature ◽

Tree Mortality ◽

Biological Control Agent ◽

Control Agent ◽

Melaleuca Quinquenervia ◽

Xylem Water Potential ◽

Simulated Drought ◽

Canker Development ◽

Low Temperature Treatments

Enhancement of the canker causing ability of Botryosphaeria ribis on melaleuca was studied with respect to stress from simulated drought, low temperature, and defoliation treatments. Low xylem water potential was related to increased level of canker development and subsequent tree mortality. Canker development was enhanced by low temperature treatments with alternating exposure to 6 C for 3 d followed by 4 d at 30 (±5) C for 8 wk. Partial defoliation did not affect canker development but complete defoliation of B. ribis-inoculated ramets resulted in tree mortality within 4 wk. Callusing of melaleuca wounds was either reduced or prevented in stressed trees. These observations suggest that stress induced on the tree enhances the tree-killing efficacy of this fungus.

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