scholarly journals Evaluation of 19 American Elm Clones for Tolerance to Dutch Elm Disease

2005 ◽  
Vol 23 (1) ◽  
pp. 21-24 ◽  
Author(s):  
A. M. Townsend ◽  
S. E. Bentz ◽  
L. W. Douglass
Keyword(s):  
Block Design ◽  
Dutch Elm Disease ◽  
Stem Cuttings ◽  
Ulmus Americana ◽  
American Elm ◽  
Foliar Symptoms ◽  
Randomized Block Design ◽  
New Harmony ◽  
Crown Dieback ◽  
Valley Forge

Abstract Rooted stem cuttings of 19 American elm (Ulmus americana L.) cultivars and selections, and rooted cuttings of two non-American elm selections, U. carpinifolia Gleditsch 51 and 970 (U. glabra Huds. x (U. wallichiana Planch. x U. carpinifolia)), along with a group of American elm seedlings, were planted in a randomized block design. When the trees were nine years old, they were inoculated with a mixed spore suspension of Ophiostoma ulmi (Buisman) C. Nannf. and Ophiostoma novo-ulmi Brasier, the causal fungi for Dutch elm disease (DED). Analyses of variance showed highly significant variation among clones in foliar symptoms 4 weeks after inoculation and in crown dieback one and two years after inoculation. After two years, 13 of the American clones showed significantly less dieback than the American elm seedlings, and 18 American clones showed significantly less injury than a randomly chosen, unselected American elm clone, 57845. The American clones with the most DED-tolerance were cultivars ‘Valley Forge,’ ‘Princeton,’ ‘Delaware,’ and ‘New Harmony,’ and selections N3487, R18-2, 290, 190, and GDH. The non-American selections 51 and 970 also exhibited high levels of disease tolerance. Most susceptible were American clones 57845, ‘Augustine,’ Crandall, W590, and the American elm seedlings. The most disease-tolerant American elm selections identified in this study are being evaluated further for possible naming and release to the nursery industry.

scholarly journals Variation among American Elm Clones in Long-term Dieback, Growth, and Survival following Ophiostoma Inoculation

2001 ◽  
Vol 19 (2) ◽  
pp. 100-103 ◽  
Author(s):  
A.M. Townsend ◽  
L.W. Douglass
Keyword(s):  
Height Growth ◽  
Dutch Elm Disease ◽  
Stem Cuttings ◽  
Ulmus Americana ◽  
Growth And Survival ◽  
American Elm ◽  
New Harmony ◽  
Crown Dieback ◽  
Valley Forge

Abstract Rooted stem cuttings of eight American elm (Ulmus americana L.) cultivars or selections, in addition to rooted stem cuttings of two non-American elm cultivars, ‘Prospector’ (U. wilsoniana Schneid.) and ‘Frontier’ (U. carpinifolia Gleditsch x U. parvifolia Jacq.), all planted in a randomized block, split-plot design, were inoculated on either one of two dates in May 1992 with a mixed spore suspension of Ophiostoma ulmi (Buisman) C. Nannf. and Ophiostoma novo-ulmi Brasier, the causal fungi for Dutch elm disease (DED). Crown dieback and survival were recorded once yearly for 7 years following inoculations, and height growth was measured after the sixth growing season. Analyses of variance and regression showed significant differences in disease severity among all clones tested. Among the American elms, crown dieback and mortality over time were least for ‘Valley Forge,’ ‘Princeton,’ and ‘New Harmony; ’ intermediate for ‘Delaware’ and selection R18-2; and greatest for selections 57845 and 11 and the cultivar American Liberty. Dieback and survival of ‘Prospector’ and ‘Frontier,’ the non-American elms, were comparable to that of the more disease-tolerant American elm clones. Height growth on surviving American elms for six years after inoculation was greatest for ‘Valley Forge’ and ‘Princeton’ and least for 57845, 11, and ‘American Liberty.’ Results demonstrate the ability of certain American elm cultivars and selections to respond and then recover from heavy doses of the two fungi which cause DED.

scholarly journals Elm Yellows Phytoplasma Lethal to Dutch Elm Disease-Resistant Ulmus americana Cultivars

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 560-560 ◽  
Author(s):  
W. A. Sinclair ◽  
A. M. Townsend ◽  
J. L. Sherald
Keyword(s):  
Fungal Pathogen ◽  
Methyl Salicylate ◽  
Dutch Elm Disease ◽  
Putative Hybrid ◽  
Field Plot ◽  
Ulmus Americana ◽  
New Harmony ◽  
Elm Yellows ◽  
Valley Forge ◽  
Hybrid Cultivar

Ulmus americana (American elm) clonal cultivars Independence, New Harmony, and Valley Forge, together with the triploid putative hybrid cultivar Jefferson, were tested for reaction to the elm yellows (EY) phytoplasma. These cultivars all possess resistance to the fungal pathogen Ophiostoma novo-ulmi (1,4) but had not been screened for EY resistance or tolerance. Procedures and conditions of the test were similar to those used previously for assessing EY tolerance of Eurasian elm cultivars (3). In brief, 9 to 15 saplings of each cultivar and of U. americana raised from seed (susceptible controls), growing in a field plot at Ithaca, NY, were challenged by grafting their mainstems with bark patches from U. americana naturally affected by EY. Six to nine additional trees of each clone and of the seedling group were left untreated as controls. Inoculations were performed in July 1999, and trees were evaluated for symptoms in early September 2000. Multiple individuals in every inoculated group developed the syndrome typical of EY in U. americana: epinasty, foliar yellowing, yellow discoloration and necrosis of root and stem phloem, odor of methyl salicylate from moist discolored phloem on first exposure to air, defoliation or sudden permanent wilting, and death (2). The numbers of trees with these symptoms, of those inoculated, were: 9 of 9 Independence, 7 of 11 New Harmony, 10 of 14 Valley Forge, 3 of 13 Jefferson, and 12 of 15 trees grown from seed. Untreated controls remained asymptomatic, except for one tree of Valley Forge and two trees grown from seed that became infected naturally and had symptoms like those in the grafted trees. Based on these results, the elm cultivars named above are typical of U. americana in susceptibility to, and intolerance of, EY phytoplasmal infection. Effective EY resistance or tolerance in this species, although once thought to occur in rare individuals (2), remains undocumented. References: (1) J. L. Sherald et al. Can. J. For. Res. 24:647, 1994. (2) W. A. Sinclair. 2000. Page 121 in: The Elms. C. P. Dunn, ed. Kluwer Academic Publishers, Norwell, MA. (3) W. A. Sinclair et al. Plant Dis. 84:1266–1270, 2000. (4) A. M. Townsend. 2000. Page 271 in: The Elms. C. P. Dunn, ed. Kluwer Academic Publishers, Norwell, MA.

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 Vegetative Propagation of American Elm (Ulmus Americana) Varieties from Softwood Cuttings

2012 ◽  
Vol 30 (2) ◽  
pp. 73-76
Author(s):  
Allison D. Oakes ◽  
Nicholas A. Kazcmar ◽  
Charles A. Maynard ◽  
William A. Powell
Keyword(s):  
Vegetative Propagation ◽  
The Other ◽  
Small Scale ◽  
Rooted Cuttings ◽  
Ulmus Americana ◽  
American Elm ◽  
Additional Testing ◽  
Control Clone ◽  
New Harmony ◽  
Valley Forge

Softwood cuttings of American elm varieties ‘Jefferson’, ‘New Harmony’, ‘Princeton’, ‘R18-2’, ‘Valley Forge’, and a tissue-cultured non-transformed control clone (BP-NT) were rooted using three different treatments to determine which method would be most suitable for small-scale propagation. The treatments included aeroponic chambers, an intermittent-mist bench in a greenhouse, and Grodan rootplugs soaked in a nutrient solution. The rootplug treatment had the highest percentage of rooted shoots (44%) followed by the intermittent-mist bench treatment (20%) and lastly by the aeroponics chambers (10%). The rooted cuttings from the rootplug treatment also looked substantially healthier and had more fresh growth four weeks after potting than the other two treatments. The Grodan rootplug treatment is recommended, but additional testing can be useful to improve the overall rooting percentage.

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 PATTERNS OF STORAGE AND FIBROUS ROOT DEVELOPMENT IN SEVERAL SWEETPOTATO CULTIVARS AND THEIR PROGENIES

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1172c-1172
Author(s):  
N. Bidiaka ◽  
V.A. Khan ◽  
C.K. Bonsi ◽  
C. Stevens ◽  
E. G. Rhoden ◽  
...  
Keyword(s):  
Field Trial ◽  
Inverse Relationship ◽  
Block Design ◽  
Soil Surface ◽  
Maximum Level ◽  
Regression Equations ◽  
Stem Cuttings ◽  
Fibrous Root ◽  
Storage Roots ◽  
Randomized Block Design

In 1991 leafless stem cuttings 7 nodes long from 4 maternal parents (`Carver', Carver ii', `TU-1892' and `Georgia-Jet') and their progenies (MP/P) were planted 3 nodes deep in greenhouse benches filled with Jiffy-Mix to determine if any similarity in storage (SR) or fibrous root (FR) patterns could be used to identify high yielding cultivars in a breeding program. The experiment was planted in a complete randomized block design with 7 replications for each treatment and the total number of SR and FR data were collected over a 9 wk period with weekly sampling. The results indicated that SR initiation was a continuos process and took from 5-9 wk before reaching a maximum level for some MP/P. There was a significant inverse relationship between SR and FR numbers, as SR increased FR decreased. SR for most MP/P were initiated at the underground node closest to the soil surface and FR at the lower two nodes. When regression equations were used on the greenhouse data to predict total number of SR that would be produced in a field trial, no significant differences were found between the number of SR initiated in the greenhouse and field trial 80 days after transplanting by some of these MP/P. However, cultivars with the highest number of storage roots in the field trial did not have the highest number of marketable roots or yield and this was probably due to differences among MP/P in the rate of root enlargement.

scholarly journals The Effect Cuttings Part and Planting Media Composition to The Growth Seeds Dragon Fruit (Hylocereus costaricensis (Web) Britton & Rose)

1970 ◽  
Vol 6 (2) ◽  
pp. 294-299
Author(s):  
Adli Rifqi Alka Siregar ◽  
Lisa Mawarni ◽  
Chairani Hanum
Keyword(s):  
Block Design ◽  
Stem Cuttings ◽  
Media Composition ◽  
Palm Fruit ◽  
Randomized Block Design ◽  
Dragon Fruit ◽  
Two Factors ◽  
Planting Materials ◽  
North Sumatra ◽  
Range Test

The factors affect the success of cuttings is composition of planting media and position of planting materials. The experiment aims to determine response growth dragon fruit seeds on various composition of planting media. It was conducted in the field of research Agriculture Faculty, North Sumatra University, Medan with the height about 32 meters above sea level on April to August 2016. The design used factorial randomized block design with two factors and three repetitions. The first factor is part of the stem cuttings with three variety i.e. bottom stem, center stem, top stem and the second factor is planting media with four variety i.e. sand 100%, sand 50% + sludge 50%, sand 50% + empty palm fruit bunches (EPFB) 50%, sand 50% + sludge 25% + EPFB 25%. Data were analyzed using analysis of variance followed by Duncan’s multiple range test (DMRT). The results showed that part of the stem cuttings hasn’t effect to all observation parameters.The best planting media composition is present in the treatment sand 50% + sludge 25% + EPFB 25%. Interaction about both of factors hasn’t effect to all observation parameters.

Preliminary assessments of shoot cold tolerance for American elm bred for enhanced tolerance to Dutch elm disease

2021 ◽  
Author(s):  
Paul Schaberg ◽  
Paula Murakami ◽  
Christopher F. Hansen ◽  
Gary J. Hawley ◽  
Christian O. Marks ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Cold Tolerance ◽  
Dutch Elm Disease ◽  
Freezing Injury ◽  
Ulmus Americana ◽  
American Elm ◽  
The North ◽  
Cold Tolerant ◽  
Using Data ◽  
Plant Hardiness

Although Dutch elm disease (DED) is the primary threat to American elm (Ulmus americana L.), we hypothesized that shoot freezing injury may also limit tree productivity and survival in the north. We assessed shoot cold tolerance and field winter injury of American elm bred for DED tolerance planted in Lemington, VT. We tested for differences in cold tolerance associated with date, maternal DED tolerance source, paternal sources from plant hardiness zones 5a, 6a and 6b (determined using data from 1996-2005), and the interactions of these. Cold tolerance was greatest in the winter, followed by fall and then spring. For all dates, cold tolerance never differed between maternal DED tolerance sources. However, in mid-winter, paternal sources from zone 5a (coldest zone) were significantly more cold tolerant than sources from zone 6b (warmest zone), and sources from zone 6a were intermediate. Field freezing injury confirmed that shoots were only marginally cold tolerant relative to ambient temperature lows.

scholarly journals The Effect of Iba and Cutting Diameter on Inducing Roots of Cotinus Coggygria Scop. and Rhus Coriaria L. (Anacardiaceae)

2017 ◽  
Vol 5 (2) ◽  
pp. 193
Author(s):  
Hassan Najman Muhamed ◽  
Nasser Abdusalam Dawod
Keyword(s):  
Vegetative Propagation ◽  
Block Design ◽  
Natural Populations ◽  
Stem Cutting ◽  
Stem Cuttings ◽  
Survival Percentage ◽  
Randomized Block Design ◽  
Short Period ◽  
Rhus Coriaria ◽  
Cotinus Coggygria

Because of the difficulty in their vegetative propagation, both Rhus coriaria L. and Cotinus coggygria Scop.  (Ancardaceae) are rarely introduced into the forest nursery trade. Vegetative propagation is practiced in forestry to produce seedlings of desired genetic properties within a short period and when seeds displaying a status of complex dormancy. In the present study, the possibility of the multiplication by stem cuttings was studied for Sumac, the high ethnobotanical shrub value and for Cotinus, the endangered shrub, to give more insight into their propagation technique. Between January-July 2014, using complete randomized block design (C.R.B.D) in four replicates, we evaluated the effectiveness of applying four different Indole-3-Butyric Acid (IBA) concentration to two stems cutting diameters in producing C. coggygria and R. coriaria. However, the former species due to the poor survival percentage (lower 5%) excluded from the analysis. Optimum results of C. coggygria were obtained with IBA 20000 mg.l -1 and cutting diameter more than 1 cm. (rooting % 60, number of roots 17.33, number of branches  3.75 and the number of leaves 19.33 while nonsignificant increase was recorded in root length. 16.33 cm.). The results indicated that Cotinus is relatively easy to propagate by stem cutting in comparing with Sumac with rootability increases significantly with increasing of IBA concentration and stem cutting diameter. Further studies are needed for more reasonable rooting results to meet the large quantity demand of elite seedling material that could be later used to restore the natural populations of C. coggygria and R. coriaria.

In vitro conservation of American elm (Ulmus americana): potential role of auxin metabolism in sustained plant proliferation

2012 ◽  
Vol 42 (4) ◽  
pp. 686-697 ◽  
Author(s):  
Mukund R. Shukla ◽  
A. Maxwell P. Jones ◽  
J. Alan Sullivan ◽  
Chunzhao Liu ◽  
Susan Gosling ◽  
...  
Keyword(s):  
Dutch Elm Disease ◽  
Multiplication Rate ◽  
Mature Trees ◽  
Endangered Tree ◽  
In Vitro Proliferation ◽  
Ulmus Americana ◽  
Auxin Metabolism ◽  
American Elm

An efficient procedure for the conservation of mature American elm ( Ulmus americana L.) trees that have survived the epidemics of Dutch elm disease and are potential sources of disease resistance is reported. The model utilizes in vitro proliferation of fresh and dormant buds from mature trees for cloning nearly 100 year old American elm trees. The key factors that influenced sustained growth and multiplication included optimization of culture process and auxin metabolism in the source tissue. Blocking the action of endogenous auxins through the addition of antiauxin in the proliferation medium was crucial for high multiplication rate and optimum shoot development. Addition of antiauxin also mitigated the decline in productivity observed with multiple subcultures, which will enable long-term conservation of selected germplasm. The most effective medium for long-term proliferation contained 5.0 µmol/L p-chlorophenoxyisobutyric acid with 2.2 µmol/L benzylaminopurine and 0.29 µmol/L gibberellic acid. Medium with 2.5 µmol/L indole-3-butyric acid was the best for rooting microshoots (89%). Rooted plantlets were readily acclimatized to the greenhouse environment with a 90% survival rate. The strategy developed for American elm will aid in increasing multiplication of resistant clones, facilitate long-term conservation of elite genotypes, and also provide an approach to improve conservation of other endangered tree species.

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