scholarly journals Description, Distribution, and Relevance of Viruses of the Forest Pathogen Gremmeniella abietina

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 654 ◽  
Author(s):  
Leticia Botella ◽  
Jarkko Hantula
Keyword(s):  
North America ◽  
Growth Rates ◽  
Mycelial Growth ◽  
Stem Canker ◽  
Optimal Temperature ◽  
Phenotypic Changes ◽  
Forest Pathogen ◽  
Shoot Blight ◽  
European Race ◽  
Biotype B

The European race of the ascomycetous species Gremmeniella abietina (Lagerberg) Morelet includes causal agents of shoot blight and stem canker of several conifers in Europe and North America, which are known to host a diverse virome. GaRV6 is the latest and sixth mycovirus species reported within G. abietina. Before its description, one victorivirus and one gammapartitivirus species were described in biotype A, two mitoviruses in both biotypes A and B and a betaendornavirus in biotype B. Possible phenotypic changes produced by mycoviruses on G. abietina mycelial growth have been reported in Spanish mitovirus-free and GaRV6-hosting G. abietina isolates, which had higher growth rates at the optimal temperature of 15 °C, but no other major differences have been observed between partitivirus-like dsRNA and dsRNA-free isolates. In this review, we reappraise the diversity of viruses found in G. abietina so far, and their relevance in clarifying the taxonomy of G. abietina. We also provide evidence for the presence of two new viruses belonging to the families Fusariviridae and Endornaviridae in Spanish isolates.

Herpotrichia coulteri. [Descriptions of Fungi and Bacteria].

1972 ◽  
Author(s):  
A. Sivanesan
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
Mycelial Growth

Abstract A description is provided for Herpotrichia coulteri. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Pinus spp., P. albicaulis, P. contorta, P. engelmannii, P. mugo var.pumilio, P. murrayana and P. nigra var. amasia. DISEASE: Brown felt-blight of pine. GEOGRAPHICAL DISTRIBUTION: North America and Europe (Cyprus, Poland, Rumania, Switzerland). TRANSMISSION: By air-borne ascospores, mycelial growth from adjacent infected leaves.

scholarly journals Shoot Blight Caused by Sirococcus tsugae on Eastern Hemlock (Tsuga canadensis) in Georgia

Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 612-612 ◽  
Author(s):  
G. R. Stanosz ◽  
D. R. Smith ◽  
J. P. Sullivan ◽  
A. M. Mech ◽  
K. J. K. Gandhi ◽  
...  
Keyword(s):  
North America ◽  
Pcr Primers ◽  
Tsuga Canadensis ◽  
Adelges Tsugae ◽  
Early Spring ◽  
Eastern Hemlock ◽  
Growth Chamber ◽  
Sterile Water ◽  
The North ◽  
Shoot Blight

Eastern hemlock (Tsuga canadensis) is an ecologically and economically important conifer from the north-central United States to the east coast of North America to the southern Appalachian Mountains. In early spring 2010, blighted shoot tips of eastern hemlock were observed at widely separated locations in the Chattahoochee National Forest in north Georgia. Damage did not appear to be directly related to hemlock woolly adelgid (Adelges tsugae) activity, which was sporadic or absent in some areas where symptoms were observed. A preliminary survey in March 2010 revealed that incidence of blighted shoots on individual trees varied, but was as high as 70%. Stems of shoots produced the previous year were frequently necrotic, had lost needles, and bore pycnidia with hyaline, two-celled conidia consistent with those of Sirococcus tsugae (2,3). Later in the spring and summer, shoots of the current year's growth became blighted, with sporulation of S. tsugae also on dead and dying needles. While S. tsugae previously has been reported on T. heterophylla, T. mertensiana, Cedrus atlantica, and C. deodara in western North America, it has only recently been reported on eastern hemlock (1), and its ability to induce shoot blight has not been proven. Pure cultures (2,3) were obtained on streptomycin-amended potato dextrose agar (PDA) and their identity was confirmed by species-specific PCR primers (4). Nuclear rDNA internal transcribed spacer sequence (554 nucleotides) also was obtained for isolate 10-05 and deposited in GenBank (Accession No. HQ256769). This sequence was found to be identical to sequences previously deposited for S. tsugae isolates. Isolate 10-05 and a second isolate (10-06) were used to inoculate potted 2-year-old eastern hemlock seedlings in a growth chamber at 20°C with a 16-h photoperiod. Conidia were collected by flooding 1-month-old colonies on PDA with sterile water. Expanding shoots on one branch of each seedling were wounded using scissors to cut the tips off needles and stems, while another branch remained nonwounded. Ten seedlings per isolate were inoculated by spraying to runoff with a suspension of 5 × 106 conidia ml–1 in sterile water, and five similarly treated control seedlings were sprayed with sterile water. Seedlings were covered with plastic bags to maintain high humidity for 4 days. Germination of conidia of each isolate incubated on water agar in this growth chamber was >80% after 24 h. Symptoms were evaluated and reisolation was attempted on streptomycin-amended PDA 2 months after inoculation. Symptoms of seedlings inoculated with either isolate included chlorotic and necrotic needle spots, browning of cut edges of needles, browning and death of needle tips and entire needles, death of stem tips with retention of dead needles, and needle loss. Symptoms of control seedlings were limited to slight browning of cut edges of needles. The fungus was reisolated from wounded shoots of 17 of 20 inoculated seedlings and nonwounded shoots of 5 of 20 inoculated seedlings and was not cultured from control seedlings. To our knowledge, this is the first report of S. tsugae in Georgia and also the first demonstration of its ability to produce symptoms that have been attributed to it on any tree species. References: (1) M. Miller-Weeks and W. Ostrofsky. USDA. Forest Service. Online publication. NA-PR-01-10, 2010. (2) A. Y. Rossman et al. For. Pathol. 38:47. (3) D. R. Smith et al. For. Pathol. 33:141, 2003. (4) D. R. Smith and G. R. Stanosz. For. Pathol. 38:156, 2008.

scholarly journals Effect of Temperature and Water Potential on Survival and Mycelial Growth of Phaeomoniella chlamydospora and Phaeoacremonium spp.

Plant Disease ◽  
2001 ◽  
Vol 85 (2) ◽  
pp. 195-201 ◽  
Author(s):  
E. C. Whiting ◽  
A. Khan ◽  
W. D. Gubler
Keyword(s):  
Water Treatment ◽  
Water Potential ◽  
Growth Rates ◽  
Mycelial Growth ◽  
Hot Water ◽  
Effect Of Temperature ◽  
Effective Control ◽  
Conidial Suspension ◽  
Hot Water Treatment ◽  
Phaeomoniella Chlamydospora

Phaeomoniella chlamydospora, a species of Phaeomoniella, and two species of Phaeoacremonium, P. inflatipes and P. aleophilum, have been associated with young grapevine decline in major production regions of California. Phaeomoniella chlamydospora has been isolated from healthy vines and inoculated but non-symptomatic vines and rooted cuttings. Effects of temperature and water potential on fungal response in culture were investigated to find effective control strategies for nurseries. Mycelial growth rates at temperatures 5 to 37°C showed a quadratic response with optimum growth rates for Phaeomoniella chlamydospora and P. aleophilum at 25°C and at 30°C for P. inflatipes. Response to water potential varied by isolates within a species, but isolates of Phaeomoniella chlamydospora were not sensitive to decreasing water potential. A conidial suspension and plugs of agar with mycelia were placed in glass vials and incubated in hot water for 15 to 120 min. Conidia were sensitive to hot-water treatment after 15 and 30 min. Nevertheless, mycelia of P. inflatipes from agar plugs grew on potato dextrose agar at 22°C after 120 min incubation at 51°C. Because the fungi were not killed by incubation in glass vials at 51°C, methods other than hot-water treatment may be more effective in eliminating Phaeomoniella chlamydospora and Phaeoacremonium spp. from dormant vine cuttings.

scholarly journals Three-dimensional methane distribution simulated with FLEXPART 8-CTM-1.1 constrained with observation data

2018 ◽  
Author(s):  
Christine D. Groot Zwaaftink ◽  
Stephan Henne ◽  
Rona L. Thompson ◽  
Edward J. Dlugokencky ◽  
Toshinobu Machida ◽  
...  
Keyword(s):  
North America ◽  
Growth Rates ◽  
Three Dimensional ◽  
Convective Transport ◽  
Inverse Modelling ◽  
Accurate Estimation ◽  
Observation Data ◽  
Vertical Profiles ◽  
Mixing Ratios ◽  
Satellite Retrievals

Abstract. A Lagrangian particle dispersion model (FLEXPART CTM) is used to simulate global three-dimensional fields of trace gas abundance. These fields are constrained with surface observation data through nudging, a data assimilation method which relaxes model fields to observed values. Such fields are of interest to a variety of applications, such as inverse modelling, satellite retrievals and estimating global growth rates of greenhouse gases. Here, we apply this method to methane using 6 million model particles filling the global model domain. For each particle methane mass tendencies due to emissions based on several inventories, loss by reaction with OH, Cl, and O(1D), as well as observation data nudging were calculated. Model particles were transported by mean, turbulent and convective transport driven by 1° × 1° ERA Interim meteorology. Nudging is applied at 79 surface stations, which are mostly included in the WDCGG database or JR-STATION network in Siberia. For simulations of one year (2013), we perform a sensitivity analysis to show how nudging settings affect modelled concentration fields. These are evaluated with a set of independent surface observations and with vertical profiles in North America (NOAA/ESRL) and Siberia (YAK-AEROSIB and NIES). FLEXPART CTM results are also compared to simulations from the global Eulerian model, TM5, based on optimized fluxes. Results show that nudging strongly improves modelled methane near the surface, not only at the nudging locations, but also at independent stations. Mean bias at all surface locations could be reduced from over 20 ppb to less than 5 ppb through nudging. Near the surface, FLEXPART CTM, including nudging, appears better able to capture methane molar mixing ratios than TM5 with optimized fluxes, based on a larger bias of over 13 ppb in TM5 simulations. The vertical profiles indicate that nudging affects model methane at high altitudes, yet leads to very little improvement in the model results there. Averaged from 19 aircraft profile locations in North America and Siberia, root-mean square error (RMSE) changes only from 16.3 to 15.7 ppb through nudging, while the mean absolute bias increases from 5.3 to 8.2 ppb. The performance for vertical profiles is thereby similar to TM5 simulations based on TM5 optimized fluxes where we found a bias of 5 ppb and RMSE of 15.9 ppb. With this rather simple model setup, we thus provide three-dimensional methane fields suitable for use as boundary conditions in regional inverse modelling, as prior information for satellite retrievals, and for more accurate estimation of mean mixing ratios and growth rates. The method should also be applicable to other long-lived trace gases.

scholarly journals Three-dimensional methane distribution simulated with FLEXPART 8-CTM-1.1 constrained with observation data

2018 ◽  
Vol 11 (11) ◽  
pp. 4469-4487 ◽  
Author(s):  
Christine D. Groot Zwaaftink ◽  
Stephan Henne ◽  
Rona L. Thompson ◽  
Edward J. Dlugokencky ◽  
Toshinobu Machida ◽  
...  
Keyword(s):  
North America ◽  
Greenhouse Gases ◽  
Growth Rates ◽  
Transport Model ◽  
Three Dimensional ◽  
Particle Dispersion ◽  
Observation Data ◽  
Vertical Profiles ◽  
Mixing Ratios ◽  
Satellite Retrievals

Abstract. A Lagrangian particle dispersion model, the FLEXible PARTicle dispersion chemical transport model (FLEXPART CTM), is used to simulate global three-dimensional fields of trace gas abundance. These fields are constrained with surface observation data through nudging, a data assimilation method, which relaxes model fields to observed values. Such fields are of interest to a variety of applications, such as inverse modelling, satellite retrievals, radiative forcing models and estimating global growth rates of greenhouse gases. Here, we apply this method to methane using 6 million model particles filling the global model domain. For each particle, methane mass tendencies due to emissions (based on several inventories) and loss by reaction with OH, Cl and O(1D), as well as observation data nudging were calculated. Model particles were transported by mean, turbulent and convective transport driven by 1∘×1∘ ERA-Interim meteorology. Nudging is applied at 79 surface stations, which are mostly included in the World Data Centre for Greenhouse Gases (WDCGG) database or the Japan–Russia Siberian Tall Tower Inland Observation Network (JR-STATION) in Siberia. For simulations of 1 year (2013), we perform a sensitivity analysis to show how nudging settings affect modelled concentration fields. These are evaluated with a set of independent surface observations and with vertical profiles in North America from the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ESRL), and in Siberia from the Airborne Extensive Regional Observations in SIBeria (YAK-AEROSIB) and the National Institute for Environmental Studies (NIES). FLEXPART CTM results are also compared to simulations from the global Eulerian chemistry Transport Model version 5 (TM5) based on optimized fluxes. Results show that nudging strongly improves modelled methane near the surface, not only at the nudging locations but also at independent stations. Mean bias at all surface locations could be reduced from over 20 to less than 5 ppb through nudging. Near the surface, FLEXPART CTM, including nudging, appears better able to capture methane molar mixing ratios than TM5 with optimized fluxes, based on a larger bias of over 13 ppb in TM5 simulations. The vertical profiles indicate that nudging affects model methane at high altitudes, yet leads to little improvement in the model results there. Averaged from 19 aircraft profile locations in North America and Siberia, root mean square error (RMSE) changes only from 16.3 to 15.7 ppb through nudging, while the mean absolute bias increases from 5.3 to 8.2 ppb. The performance for vertical profiles is thereby similar to TM5 simulations based on TM5 optimized fluxes where we found a bias of 5 ppb and RMSE of 15.9 ppb. With this rather simple model setup, we thus provide three-dimensional methane fields suitable for use as boundary conditions in regional inverse modelling as a priori information for satellite retrievals and for more accurate estimation of mean mixing ratios and growth rates. The method is also applicable to other long-lived trace gases.

scholarly journals Resistance to Thiophanate-Methyl in Botrytis cinerea Isolates From Californian Vineyards and Pistachio and Pomegranate Orchards

Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1069-1075
Author(s):  
Hervé F. Avenot ◽  
David P. Morgan ◽  
Joel Quattrini ◽  
Themis J. Michailides
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Gray Mold ◽  
Fitness Components ◽  
Thiophanate Methyl ◽  
Significant Difference ◽  
Shoot Blight ◽  
Growth Assay ◽  
Free Media ◽  
Weak Resistance

In this study, a mycelial growth assay was used to evaluate the sensitivity to thiophanate-methyl of 144 Botrytis cinerea isolates (collection A) from Californian vineyards and pistachio and pomegranate orchards. Based on the effective concentration that inhibits 50% of growth (EC50) values for mycelial growth inhibition on fungicide-amended media, 3, 28, 10, and 58% of the isolates showed sensitivity (SS; EC50 < 1 µg/ml), low resistance (LR; 1 < EC50 < 10 µg/ml), weak resistance (WR; 10 < EC50 < 50 µg/ml), and high resistance (HR; EC50 > 100 µg/ml) toward thiophanate-methyl, respectively. The LR and HR phenotypes were observed in pistachio and pomegranate orchards, even though pomegranate was not sprayed with thiophanate-methyl. Sensitivity to thiophanate-methyl of a historical collection of 257 B. cinerea isolates (collection B) isolated from pistachio orchards in 1992, 2005, and 2006 was assessed on potato dextrose agar amended with thiophanate-methyl at the discriminatory concentration of 10 µg/ml. Average percentages of thiophanate-methyl–resistant isolates were 50, 72, and 64% in the orchards in 1992, 2005, and 2006, respectively. A study of fitness components of selected thiophanate-methyl–resistant (LR, WR, and HR) and –sensitive (SS) isolates from collection A did not reveal any significant difference between them with respect to mycelial growth on fungicide-free media and pathogenicity on cultivar Crimson Seedless berries. Comparison of β-tubulin sequences from resistant and sensitive phenotypes revealed that a glutamic acid at position 198 was changed to alanine in all HR isolates and three LR isolates. The occurrence of thiophanate-methyl resistance in B. cinerea populations should be considered when designing spray programs against blossom and shoot blight of pistachio and gray mold of grape.

LEAF AND SHOOT BLIGHT OF POPLARS (SECTION TACAMAHACA SPACH) CAUSED BY VENTURIA POPULINA (VUILL.) FABRIC

1961 ◽  
Vol 39 (4) ◽  
pp. 875-890 ◽  
Author(s):  
B. W. Dance
Keyword(s):  
North America ◽  
Experimental Evidence ◽  
Populus Balsamifera ◽  
Balsam Poplar ◽  
Shoot Blight ◽  
Twig Blight

This study is concerned with the recognition, pathology, and taxonomy of Venturia populina (Vuill.) Fabric. (= Didymosphaeria populina Vuill.), and its imperfect stage Pollaccia elegans Serv., which is shown to cause a leaf and twig blight of balsam poplar (Populus balsamifera L.) in North America. Venturia populina may be confined to hosts of the section Tacamahaca Spach of the genus Populus, although experimental evidence presented here suggests that poplars of the section Aigeiros Duby also may be susceptible, as they are in Europe. The binomial Fusicladium radiosum (Lib.) Lind, which was listed by Servazzi as a pro parte synonym of P. elegans, is shown to have been commonly applied in North America to the fungus representing Pollaccia radiosa (Lib.) Bald. & Cif., a pathogen which is confined to poplars of the section Leuce Duby in both Europe and North America. Fusicladium radiosum (Lib.) Lind var. balsamiferae J. J. Davis, however, is shown to be a synonym of P. elegans.

Irrigating seedling tea in Southern Tanzania: effects on total yields, distribution of yield and water use

1974 ◽  
Vol 83 (2) ◽  
pp. 363-378 ◽  
Author(s):  
M. K. V. Carr
Keyword(s):  
Water Use ◽  
Growth Rates ◽  
Low Temperatures ◽  
Rainy Season ◽  
Field Capacity ◽  
Stem Canker ◽  
Dry Season ◽  
External Factors ◽  
Limited Growth ◽  
Tea Industry

SUMMARYIn a dry area of Southern Tanzania with a single rainy season irrigation during the six-month-long dry season (May-November) doubled the total annual yield of tea and at the same time evened its distribution over the year to some extent. Other factors including low temperatures limited growth rates during the period June-September despite irrigation, whilst a lull in production in November appeared to be unrelated to external factors. Roots were traced to depths of about 4·3 m and by the end of the dry season unirrigated bushes were drying the soil below 3m. In general total yields decreased with decreasing frequency of irrigation and quantity of water applied but because these plants were deep rooting they could withstand deficits up to 100 mm without a reduction in yield, equivalent to a loss of about 25% of the total available water in the profile. There was some evidence that the most economical use of water occurred when the soil was not rewetted to field capacity at each irrigation, although yields were then less. Irrigation also reduced the incidence of a stem canker, Phomopsis theae. The implications of these results to the tea industry of East Africa are discussed.

Growth and spore production of Plectosporium tabacinum

2001 ◽  
Vol 79 (11) ◽  
pp. 1297-1306 ◽  
Author(s):  
Wenming Zhang ◽  
Michelle Sulz ◽  
Karen L Bailey
Keyword(s):  
Carbon Source ◽  
Carbon Concentration ◽  
Mycelial Growth ◽  
Liquid Culture ◽  
C:N Ratio ◽  
Spore Production ◽  
Optimal Temperature ◽  
Agar Media ◽  
Galium Spurium ◽  
Optimal Ph

Plectosporium tabacinum (van Beyma) M.E. Palm, W. Gams, et Nirenberg has been evaluated as a bioherbicide for the control of Galium spurium L. (false cleavers). Little is known, however, about the specific culture and sporulation requirements of this fungus on standard agar media. In addition, information on submerged liquid culture spore production is not available. This information is important for the successful culture and further development of this fungus as a biocontrol agent. This study characterized mycelial growth and sporulation of Plectosporium tabacinum on 14 different standard agar media over a range of light regimes, pH, and temperatures. Conditions required for submerged liquid culture spore production and resulting weed control efficacy were also assessed. This included the effect of liquid culture medium and pH and the effect of carbon source, nitrogen source, carbon concentration, and carbon–nitrogen (C:N) ratio. Potato dextrose agar is the best agar medium for growth and spore production. On standard agar media, growth and spore production was not influenced by light regime. Medium pH did not affect mycelial growth and spore germination but the optimal pH for spore production was 7.0. The optimal temperature for the mycelial growth was between 22 and 25°C, but the optimal temperature for spore production was at either 20 or 30°C, depending upon the nutrient medium. Temperatures above 20°C were required to achieve greater than 90% spore germination. For submerged liquid culture spore production, Richard's solution (RS) is the best liquid medium for spore production. The optimal pH was 7.0 for RS but varied with culture media. Potassium nitrate and corn starch were the best nitrogen source and carbon source, respectively. A medium with a carbon concentration of 12.6 g/L and a C:N ratio of 7.5:1 is optimum for spore production and weed control efficacy.Key words: Plectosporium tabacinum, bioherbicide, mass production, fermentation, false cleavers, Galium spurium.

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