The discovery of three genetic races of the dwarf mistletoe Arceuthobium americanum (Viscaceae) provides insight into the evolution of parasitic angiosperms

2002 ◽  
Vol 11 (3) ◽  
pp. 387-405 ◽  
Author(s):  
Cheryl A. Jerome ◽  
Bruce A. Ford
Keyword(s):  
Dwarf Mistletoe ◽  
Arceuthobium Americanum ◽  
Parasitic Angiosperms ◽  
Insight Into

scholarly journals Effects of Lodgepole Pine Dwarf Mistletoe, Arceuthobium americanum, on Jack Pine, Pinus banksiana, Growth in Manitoba

2004 ◽  
Vol 118 (4) ◽  
pp. 595 ◽  
Author(s):  
Brock Epp ◽  
Jacques C. Tardif
Keyword(s):  
Pinus Banksiana ◽  
Growth Models ◽  
Lodgepole Pine ◽  
Wood Quality ◽  
Basal Area ◽  
Jack Pine ◽  
Dwarf Mistletoe ◽  
Tree Form ◽  
Arceuthobium Americanum ◽  
Pine Trees

The Lodgepole Pine Dwarf Mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is an important pathogen of Jack Pine (Pinus banksiana Lamb.). Dwarf Mistletoe alters tree form, suppresses growth, and reduces volume and overall wood quality of its host. Stem analysis and a 3-parameter logistic regression model were used to compare the growth of heavily and lightly to non infected Jack Pine trees. At the time of sampling, no significant reduction in diameter at breast height and basal area were observed in heavily infected trees. However, a significant reduction in height and volume and an increase in taper were observed in heavily infected trees. Growth models predicted a 21.1% lower basal area, 23.4% lower height and 42.1% lower volume by age 60 for the high infection group.

scholarly journals Callus Culture of Arceuthobium americanum Nutt. ex Englem. and Explant Response to Varying Auxin and Cytokinin Concentrations

2012 ◽  
Vol 21 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Lyssa L. Martin ◽  
Cynthia Ross Friedman ◽  
Ronald G. Smith
Keyword(s):  
North America ◽  
Callus Culture ◽  
Shoot Organogenesis ◽  
Coniferous Forests ◽  
Western North America ◽  
Laboratory Studies ◽  
Dwarf Mistletoe ◽  
Arceuthobium Americanum ◽  
Infected Area

The lodgepole pine dwarf mistletoe Arceuthobium americanum is a severe pest in coniferous forests of western North America.  To facilitate laboratory studies of this obligate parasite, a modified White’s medium was used for in vitro culture; the concentrations of IAA and Kn were varied to determine optimal IAA/Kn ratios.  It was found that explant health was related to the concentration of IAA (p = 0.008), but not Kn (p = 0.937), and that explants were healthiest at an IAA/Kn ratio of 0.1.  Radicular apices were generated at IAA/Kn ratios of 1.0 or greater, but no shoot organogenesis was observed.  These data suggest that A. americanum is more sensitive to auxins than cytokinins.  Parasites of plants are known to secrete high levels of cytokinins, which stimulate the host to shuttle nutrients to the infected area, and so we suspect that A. americanum has reduced cytokinin sensitivity.   Key words: Callus culture, Arceuthobium americanum, Explant, Response, Cytokinin, Insensitivity   D.O.I. 10.3329/ptcb.v21i1.9557   Plant Tissue Cult. & Biotech. 21(1): 1-10, 2011 (June)

Adhesives for seed placement during artificial inoculation of Pinus banksiana seedlings with the dwarf mistletoe Arceuthobium americanum

2003 ◽  
Vol 81 (10) ◽  
pp. 1039-1043 ◽  
Author(s):  
J P Brandt ◽  
Y Hiratsuka ◽  
D J Pluth
Keyword(s):  
Pinus Banksiana ◽  
Polyvinyl Acetate ◽  
Jack Pine ◽  
Artificial Inoculation ◽  
Effect Of Temperature ◽  
Dwarf Mistletoe ◽  
Arceuthobium Americanum ◽  
Randomized Design ◽  
Synthetic Adhesives ◽  
Seed Placement

Lodgepole pine dwarf mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is a serious pest of jack pine (Pinus banksiana Lamb.). Research investigating factors such as host resistance, influence of host nutrition on infection rates, and effect of temperature and humidity on the life cycle of the pathogen is limited by our ability to consistently infect the host through artificial means. A greenhouse experiment utilizing a completely randomized design with four replicates was conducted to test the effectiveness of three chemical compounds and the natural viscin of the dwarf mistletoe seed to act as adhesives during artificial inoculation of jack pine seedlings. Synthetic adhesives used were anhydrous lanolin (LAN), hydroxypropylcellulose (HPC), and polyvinyl acetate (PVA). The percentage of infected seedlings was significantly higher with HPC compared with that of PVA, LAN, and the seed's viscin. HPC, as the superior adhesive, and the techniques described should allow consistent production of seedlings infected with dwarf mistletoe for research, regardless of the dwarf mistletoe species involved. Problems encountered during the testing of the adhesives are discussed in relation to the nature of the adhesives and their application.Key words: anhydrous lanolin, hydroxypropylcellulose, polyvinyl acetate, viscin.

Vegetative and floral development in the pistillate plant of Arceuthobium americanum (lodgepole pine dwarf mistletoe): an environmental scanning electron microscopy study of its phenology and shoot organization

Botany ◽  
2017 ◽  
Vol 95 (3) ◽  
pp. 337-346
Author(s):  
Dylan J. Ziegler ◽  
Cynthia Ross Friedman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lodgepole Pine ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Dwarf Mistletoe ◽  
Three Generations ◽  
Arceuthobium Americanum ◽  
Female Flowers ◽  
Scanning Electron

Dwarf mistletoes (DM), genus Arceuthobium, are dioecious parasitic flowering plants having prolonged life cycles lasting six years, culminating with explosive discharge of the single seed from the fruit. Arceuthobium americanum Nutt. ex Engelm., the lodgepole pine dwarf mistletoe, infects lodgepole pine (Pinus contorta subsp. latifolia (Engelm.) Critchfield) in western North America, compromising the forest economy. Highly reduced flowers appear no later than two years following shoot development, with female flowers appearing and persisting for over two years. Development of the pistillate plant, including initiation of floral growth, has not been fully explored. Here, we used environmental scanning electron microscopy to demark phenological waypoints throughout the pistillate plant’s development. As successive crops of female flowers emerged every year, up to three generations of flowers/fruit could be found on a single shoot in late summer; we used these three generations to delineate specific developmental stages. Vegetative shoots could initiate growth at any time within the growing season, could assume a terminal position, could also adopt sympodial branching, but were never whorled or adventitious. Floral branches, however, could initiate adventitiously from older nodes in a whorled pattern, and could house flowers/fruits of any generation. Vegetative and floral units were structurally homogeneous, suggesting shared developmental pathways.

Extreme cold temperatures and survival of overwintering and germinated Arceuthobium americanum seeds

2004 ◽  
Vol 34 (1) ◽  
pp. 174-183 ◽  
Author(s):  
J P Brandt ◽  
Y Hiratsuka ◽  
D J Pluth
Keyword(s):  
Pinus Banksiana ◽  
Exposure Period ◽  
Jack Pine ◽  
Western Canada ◽  
Dwarf Mistletoe ◽  
Cold Temperatures ◽  
Arceuthobium Americanum ◽  
Northern Areas ◽  
Jack Pine Forests ◽  
Extreme Cold

Lodgepole pine dwarf mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is one of the most damaging pathogens of jack pine (Pinus banksiana Lamb.) in western Canada. Jack pine forests in the colder, more northerly areas, however, are free of dwarf mistletoe, suggesting that the pathogen is limited by low temperature. The effect of extreme cold temperatures on germination rates of overwintering dwarf mistletoe seeds and survival of dwarf mistletoe germinants was evaluated. Germinative ability of overwintering seeds increased with increasing temperatures between –39 and –35 °C, regardless of seed source. Exposure period also strongly influenced germination rates. Exposure to temperatures near –38, –46, or –53 °C for 96 or 144 h was almost always lethal. At –37 °C, germination was greater after 48 h than after 96 h, although it was still significantly lower than in the controls. Temperatures down to –6 °C in late spring did not reduce germinant survival. Overall, these results may explain the absence of dwarf mistletoe from northern areas commonly exposed to periods in winter with minimum temperatures below about –40 °C. These areas are potentially at risk from the pathogen if the climate of Canada's northern interior continues to warm as it has over the last several decades.

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