Factors Affecting Growth of Ophiostoma ulmi on Elm Callus Tissue

1991 ◽  
Vol 9 (4) ◽  
pp. 211-215
Author(s):  
Subhash C. Domir ◽  
Lawrence R. Schreiber ◽  
Jann M. Ichida
Keyword(s):  
Significant Interaction ◽  
Callus Tissue ◽  
Fungal Growth ◽  
Dutch Elm Disease ◽  
Inoculum Concentration ◽  
Ophiostoma Ulmi ◽  
Factors Affecting ◽  
American Elm ◽  
Intermediate Resistance

Abstract We examined growth of the Dutch elm disease fungus, Ophiostoma ulmi, on callus derived from a susceptible American elm (Ulmus amencana, selection A), an American elm of intermediate resistance (U. americana, selection 8630), and a resistant Siberian elm (Ulmus pumlia) at 16, 22, and 28°C (61,72, and 83°F) and inoculation concentrations of 15 × 106, 2 × 106, or 0.3 × 106 conidia/ml. After 72 hours, the rates of fungal growth for all treatments were most rapid on calli from the American 8630 selection followed by the American A and Sibenan selections. While fungal growth was more rapid over American 8630, it was more dense on American A. Most rapid fungal growth occurred at 22°C (72°F) and was directly proportional to the inoculum concentration. A significant interaction was noted between callus source and temperature.

scholarly journals Effect of Elm Selection, Explant Source and Medium Composition on Growth of Ophiostoma ulmi on Callus Cultures

1992 ◽  
Vol 10 (1) ◽  
pp. 59-62
Author(s):  
Subhash C. Domir ◽  
Lawrence R. Schreiber ◽  
Jann M. Ichida ◽  
Steven M. Eshita
Keyword(s):  
Growth Rate ◽  
High Performance ◽  
Callus Tissue ◽  
Fungal Growth ◽  
Callus Cultures ◽  
Medium Composition ◽  
Dutch Elm Disease ◽  
Ophiostoma Ulmi ◽  
American Elm ◽  
Explant Source

Abstract We examined the effects of elm selection, explant source and media composition on growth of the Dutch elm disease (DED) fungus Ophiostoma ulmi on callus cultures. Calluses were generated from leaf and stem tissue of an American elm (Ulmus Americana L.) seedling (A), susceptible to the disease; an American elm selection 8630, resistant to the disease; and a Siberian elm (U. pumila L.) seedling, also resistant to DED. Calluses were generated on modified Murashige-Skoog (MMS) medium, either with (MMSC) or without coconut milk. Explant source did not affect the fungal growth rate on the callus. Rate of O. ulmi growth on American elm A callus was similar on both media; on Siberian and 8630, fungal growth rate was more rapid on callus cultured on MMS than on MMSC. However, in the absence of callus tissue, O. ulmi growth on MMSC medium was more than five times as rapid as it was on MMS. We observed significant interactions between explant source and selection, and between medium and selection. Fungal growth was always more rapid on American A, and American 8630 then on Siberian. Scanning electron microscopy revealed heavy fungal sporulation on American A, slight on Siberian and none on American 8630. High performance liquid chromatography analysis showed that the secondary metabolic profiles were distinguishable for callus tissue versus explant tissue, but were similar for calli generated from different explant sources.

Accumulation of mansonones in callus cultures of Ulmus americana L. in the absence of a fungal-derived elicitor

1997 ◽  
Vol 75 (3) ◽  
pp. 513-517 ◽  
Author(s):  
F. G. Meier ◽  
W. R. Remphrey
Keyword(s):  
Culture Media ◽  
Fungal Growth ◽  
Callus Cultures ◽  
Dutch Elm Disease ◽  
Ulmus Americana ◽  
Ophiostoma Ulmi ◽  
Medium Components ◽  
Tissue Culture Media ◽  
Wound Reaction ◽  
Accumulation Ability

The Dutch elm disease pathogens Ophiostoma ulmi (Buism.) Nannf. and Ophiostoma novo-ulmi Brasier elicit the production of phytoalexins called mansonones in the American elm (Ulmus americana L.). As part of a larger investigation, it was revealed that mansonone elicitation in callus culture does not require the Dutch elm disease pathogens, as has been reported in other studies. The objective of this study was to determine the nature and timing of the nonfungal elicited mansonone accumulation in U. americana callus. Initially, 7-week-old calli were subjected to inoculations with various fungal growth medium components. Mansonone production occurred in all treatments, indicating that it was stimulated prior to the addition of the medium components. Next, cotyledons and calli at various stages of development were analysed for the production of mansonones to determine the timing of its production. Mansonone production appeared to be correlated with the initiation of callus production and may be related to the callus wound reaction. As the callus aged, its colour changed from white–green to brown possibly as a result of phytoalexin accumulation. Additional experiments in which the cotyledon source, agar source, and type of plant tissue culture media were modified resulted in no change to the mansonone accumulation ability of the callus. The discrepancy between our results and those of other researchers could be due to differences in the method of mansonone quantification, namely, that our method is more sensitive and led to the detection of mansonones where previously none had been found. Further research must be done in this area to investigate this mansonone accumulation. Key words: phytoalexin, Dutch elm disease, mansonone, Ulmus americana, callus.

scholarly journals Variation in Response of Selected American Elm Clones to Ophiostoma ulmi

1995 ◽  
Vol 13 (3) ◽  
pp. 126-128 ◽  
Author(s):  
A.M. Townsend ◽  
S.E. Bentz ◽  
G.R. Johnson
Keyword(s):  
Dutch Elm Disease ◽  
Main Trunk ◽  
Ulmus Americana ◽  
Disease Symptoms ◽  
Ophiostoma Ulmi ◽  
American Elm ◽  
Causal Fungus ◽  
One Year ◽  
Crown Dieback ◽  
High Degree

Abstract Ramets of nine American elm (Ulmus americana L.) clones or cultivars were planted with ramets of Ulmus ‘Frontier’, Ulmus ‘Prospector’, and American elm seedlings in a randomized block, split-plot design. When they were three years old, the trees were inoculated in the main trunk on either one of two selected dates in May with a spore suspension of Ophiostoma ulmi, the causal fungus for Dutch elm disease (DED). Analyses of variance showed significant variation among clones and between inoculation dates in disease symptoms four weeks and one year after inoculation. Inoculations made on May 18 generally created significantly more symptoms than inoculations made only nine days later. Four-week symptom expression was influenced also by a significant interaction between clonal or seedling group and inoculation date. When data from both inoculation dates were combined, six American elm clones (‘American Liberty’, ‘Princeton’, 680, R18–2, 180, and 3) showed significantly fewer foliar symptoms after four weeks than the American elm seedlings and three other American elm clones. Five of these same six more tolerant American clones averaged significantly less crown dieback after one year than the other American clones or seedlings tested. One of the American elm clones (clone 3) showed a level of disease tolerance equal statistically to ‘Frontier’ and ‘Prospector’, two cultivars which have shown a high degree of tolerance to DED in other studies.

scholarly journals 041 OPTIMIZATION OF ULMUS SUSPENSION CULTURES FOR ELICITOR/PHYTOALEXIN EXPERIMENTS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 433f-433
Author(s):  
V. M. Gingas ◽  
J. C. Kamalay ◽  
S. C. Domir
Keyword(s):  
Phenolic Compounds ◽  
Cell Cultures ◽  
Callus Tissue ◽  
Suspension Cultures ◽  
Dutch Elm Disease ◽  
Ms Medium ◽  
Ophiostoma Ulmi ◽  
Modified Ms Medium

Suspension cultures of five elm selections (U. americana A, 680, 8630 and Del 2 and U. pumila S) exhibiting a range of susceptibility responses to the Dutch Elm Disease fungus (Ophiostoma ulmi) have been successfully established for future elicitor/phytoalexin studies. Calli initiated from foliar tissues of mature, greenhouse-grown trees cultured on a solid modified MS medium containing 2,4-D and BA were adapted to a liquid modified MS medium containing BA and either IAA or NAA. Cells were grown in either the presence or absence of light with continuous agitation. Uniform, rapidly dividing cell cultures were achieved when friable white or tan calli were grown in the medium containing 1 mg/l each NAA and BA in darkness. Cultures yielding an abundance of phenolic compounds exhibited decreased cell uniformity and proliferation. Increased phenolic production was associated with the presence of phenolics in the initial callus tissue, exposure to light and the use of IAA as the auxin source.

scholarly journals Host-Parasite Relationships of Susceptible and Resistant Elm Callus Cultures Challenged with Ophiostoma ulmi (Buisman) Nannf.

1996 ◽  
Vol 14 (1) ◽  
pp. 33-38
Author(s):  
C. R. Krause ◽  
J. M. Ichida ◽  
L. R. Schreiber ◽  
S. Domir
Keyword(s):  
Callus Tissue ◽  
Hyphal Growth ◽  
Callus Cultures ◽  
Host Cells ◽  
Ulmus Americana ◽  
Ophiostoma Ulmi ◽  
American Elm ◽  
Electron And Light Microscopy ◽  
Host Parasite ◽  
Irregular Growth

Abstract Ultrastructural effects of Ophiostoma ulmi (Buisman) Nannf..(= Ceratocystis ulmi Buisman C. Moreau) on susceptible American elm (Ulmus americana L.) callus tissue consisted of extensive vacuolation, accumulation of cytolytic substances, and plasmolysis when viewed with electron and light microscopy. Infected resistant American elm callus tissue revealed slight cell wall damage with some phenolic-like deposits but adjacent cells, membranes, mitochondria and nuclei were intact. Fungal hyphae that adhered to callus grown from susceptible American elm plants were regularly observed. Sparse hyphal growth was not suspended above resistant American elm callus cells. Callus from nonhost and resistant elms showed reduced hyphal growth between host cells compared to susceptible elm with increased accumulation of extracellular, phenolic-like deposits than in callus of American elm. The fungal structures on resistant tissue showed evidence of irregular growth and morphology. The latter suggest a phytoalexin-like response by the resistant American elm callus tissue.

Studies on the Fungal Pathogen of Dutch Elm Disease

1981 ◽  
Vol 39 ◽  
pp. 400-401
Author(s):  
H.M. Mazzone ◽  
G. Wray ◽  
R. Zerillo
Keyword(s):  
Fungal Pathogen ◽  
Fungal Growth ◽  
Polymyxin B ◽  
The United States ◽  
Dutch Elm Disease ◽  
Effective Control ◽  
Sabouraud Agar ◽  
Total Inhibition ◽  
Zones Of Inhibition ◽  
Control Plate

The fungal pathogen of the Dutch elm disease (DED), Ceratocystis ulmi (Buisman) C. Moreau, has eluded effective control since its introduction in the United States more than sixty years ago. Our studies on DED include establishing biological control agents against C. ulmi. In this report we describe the inhibitory action of the antibiotic polymyxin B on the causal agent of DED.In screening a number of antibiotics against C. ulmi, we observed that filter paper discs containing 300 units (U) of polymyxin B (Difco Laboratories) per disc, produced zones of inhibition to the fungus grown on potato dextrose agar or Sabouraud agar plates (100mm x 15mm), Fig. 1a. Total inhibition of fungal growth on a plate occurred when agar overlays containing fungus and antibiotic (polymyxin B sulfate, ICN Pharmaceuticals, Inc.) were poured on the underlying agar growth medium. The agar overlays consisted of the following: 4.5 ml of 0.7% agar, 0.5 ml of fungus (control plate); 4.0 ml of 0.7% agar, 0.5 ml of fungus, 0.5 ml of polymyxin B sulfate (77,700 U). Fig. 1, b and c, compares a control plate and polymyxin plate after seven days.

The Microscopy of Compatibility and Incompatibility in Ulmus

1985 ◽  
Vol 43 ◽  
pp. 504-505
Author(s):  
B. L. Redmond ◽  
Christopher F. Bob
Keyword(s):  
Dutch Elm Disease ◽  
Economic Losses ◽  
Hybrid Progeny ◽  
Ulmus Pumila ◽  
Ulmus Americana ◽  
American Elm ◽  
Asian Species ◽  
Ulmus Parvifolia ◽  
Initial Appearance ◽  
Chinese Elm

The American Elm (Ulmus americana L.) has been plagued by Dutch Elm Disease (DED), a lethal disease caused by the fungus Ceratocystis ulmi (Buisman) c. Moreau. Since its initial appearance in North America around 1930, DED has wrought inexorable devastation on the American elm population, triggering both environmental and economic losses. In response to the havoc caused by the disease, many attempts have been made to hybridize U. americana with a few ornamentally less desirable, though highly DED resistant, Asian species (mainly the Siberian elm, Ulmus pumila L., and the Chinese elm Ulmus parvifolia Jacq.). The goal is to develop, through breeding efforts, hybrid progeny that display the ornamentally desirable characteristics of U. americana with the disease resistance of the Asian species. Unfortunately, however, all attempts to hybridize U. americana have been prevented by incompatibility. Only through a firm understanding of both compatibility and incompatibility will it be possible to circumvent the incompatibility and hence achieve hybridization.

scholarly journals Muskmelon seed germination and seedling development in response to seed priming

2003 ◽  
Vol 60 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
Seed Germination ◽  
Cucumis Melo ◽  
Germination Rate ◽  
Fungal Growth ◽  
Seed Priming ◽  
Seedling Development ◽  
Factors Affecting ◽  
Total Seed ◽  
Cucumis Melo L ◽  
Osmotic Potentials

Important factors affecting seed priming have not been extensively reported in muskmelon (Cucumis melo L.) studies. The optimization of the seed priming technique becomes very important at the commercial scale. Little information has been reported on seedling development of muskmelon subsequent to seed priming. Seeds of muskmelon were primed in darkness at 25°C in different solutions and three osmotic potentials. Seeds were also primed with and without aeration during different periods. In relation to osmotic solutions, an osmotic potential around -1.30 MPa is most adequate for muskmelon priming. Salt solutions gave better germination rate but were deleterious for seed germination, especially at higher osmotic potentials. Aeration of the soaking salt solution gave faster germination at 17°C, and because of the early germination, these treatments probably presented a better seedling development. Deleterious effect on total seed germination was observed for long soaking periods with aeration. Fungal growth increased on seeds primed in aerated solutions. Seeds from priming treatments had a better germination rate and seedling development under 17 and 25°C.

Factors Affecting Personal Space toward a Group

1977 ◽  
Vol 45 (3) ◽  
pp. 735-743 ◽  
Author(s):  
Darhl M. Pedersen
Keyword(s):  
Group Size ◽  
Significant Interaction ◽  
Personal Space ◽  
Target Person ◽  
Target Groups ◽  
Factors Affecting ◽  
Face To Face ◽  
Main Effect ◽  
Males And Females ◽  
Left Target

The personal space of 160 males and 160 females was measured relative to target groups whose characteristics varied in size (1, 2, 3, 4), type of person (men, women, boy, and girl), and direction of orientation (right, front, left). Two analyses of variance were completed: (a) sex of subject × type of target person × group size × direction of facing and (b) sex of subject × direction of facing of right target × direction of facing of left target person × man-woman composition. Personal space was smaller toward groups not containing a man than for those containing a man, for groups of children than adults when approaching face to face, for groups of females than males when approaching from behind, for groups facing away than for groups facing at right angles than for groups facing toward. Although group size was involved in a significant interaction with type of person and direction of facing, it did not produce a significant main effect. Sex of subject also was not significant, showing that males and females exhibited generic social schemas in personal spacing toward groups.

Analytical electrofocusing and two-dimensional electrophoresis of proteins extracted from the mycelia of aggressive and nonaggressive strains of Ophiostoma ulmi

1986 ◽  
Vol 64 (9) ◽  
pp. 2073-2081 ◽  
Author(s):  
Robert S. Jeng
Keyword(s):  
Dutch Elm Disease ◽  
Two Dimensional ◽  
Polyacrylamide Gels ◽  
Ophiostoma Ulmi ◽  
Two Dimensional Electrophoresis ◽  
Coomassie Blue ◽  
Isoelectric Points ◽  
Additional Protein ◽  
Dimensional Electrophoresis ◽  
Electrophoresis Of Proteins

Soluble mycelial proteins from Ophiostoma ulmi (Buism.) Nannf., the causal agent of Dutch elm disease, were separated by analytical electrofocusing and two-dimensional electrophoresis in polyacrylamide gels. Results showed the aggressive and nonaggressive strains of this pathogen each had about 60 Coomassie blue stained bands having isoelectric points from 3 to 7. Both strains of this fungus had their own characteristic electrofocusing patterns. Nonaggressive isolate S116, for example, lacked two protein bands, one near the anode and one near the cathode, but it had five additional protein bands distributed from pH 4 to 6. Two-dimensional electrophoresis of total soluble proteins depicted that there were 36 proteins found to be specific for the nonaggressive isolate S116 and 12 proteins for the aggressive isolate RR2.

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