B Chromosomes in White Spruce

1977 ◽  
Vol 198 (1133) ◽  
pp. 325-344 ◽  
Keyword(s):  
North America ◽  
Picea Glauca ◽  
Constitutive Heterochromatin ◽  
White Spruce ◽  
B Chromosomes ◽  
Experimental Results ◽  
The Other ◽  
Differential Mortality ◽  
X Chromosomes ◽  
Engelmann Spruce

In Picea glauca , the White Spruce, supernumerary, B chromosomes were found in 48 out of 51 North American populations investigated. The B chromosomes are of two kinds. The more common (B1) is metacentric. The other (B2) has a subterminal centromere. Giemsa staining at metaphase shows no trace of constitutive heterochromatin in B chromosomes, yet at interphase the B chromosomes are heteropycnotic. It is argued that the capacity for heterochromatization of the B chromosomes at interphase may be associated with gene inactivation as in the X chromosomes of female mammals. B2 is found in western regions only, i. e. west of the 95th meridian. B1 is found in both western and eastern regions but its frequency varies substantially among populations. In general there is a reduction in B frequency from east to west in both western and eastern regions of North America. Experimental results support the view that such variation is adaptive and, in part at least, caused by the differential mortality of plants with and without B chromosomes in particular environments. Evidence is presented which indicates that B2 was introduced into White Spruce following hybridization with Engelmann Spruce.

Taxonomy and origin of present-day morphometric variation in Picea glauca (×engelmannii) seed-cone scales in North America

2006 ◽  
Vol 84 (7) ◽  
pp. 1129-1141 ◽  
Author(s):  
W.L Strong ◽  
L.V. Hills
Keyword(s):  
Rocky Mountains ◽  
Picea Glauca ◽  
White Spruce ◽  
Black Hills ◽  
Picea Engelmannii ◽  
Morphometric Variation ◽  
Engelmann Spruce ◽  
Seed Cone ◽  
Northern United States ◽  
Cone Scale

White spruce ( Picea glauca (Moench) Voss) and Engelmann spruce ( Picea engelmannii Parry ex Engelm.) seed-cones from 676 sites in Canada and the northern United States were analyzed to determine the degree and spatial extent of interspecific hybridization. Fifteen cone-scale variables were analyzed, with percent free-scale and scale shape considered best for differentiating these taxa. The results show that putative Engelmann spruce and their hybrids occur mostly in the vicinity of the Rocky Mountains. Putative white spruce occurs across Canada east of the Rocky Mountains, whereas white × Engelmann hybrids occur eastward to Manitoba and northward to 68° latitude in northwest Canada. To explain the occurrence of the latter taxon hundreds of kilometres from an Engelmann spruce pollen source, it is hypothesized that palaeohybridization occurred during the Wisconsinan glacial period, probably in the southern Montana – Wyoming – Black Hills (South Dakota) region, with the resulting hybrids spreading north and northeastward into interior Canada following the retreat of the Laurentide glacier. White and Engelmann spruce have morphologically distinct cone-scales, whereas their hybrids have intermediate characteristics. An emended species ( Picea albertiana ) and two subspecies (P. albertiana subsp. albertiana and P. albertiana subsp. ogilviei) are proposed to account for morphological intermediates between the parent species.

scholarly journals Modeled diameter growth response to intermediate treatments of planted white spruce (Picea glauca) affected by eastern spruce budworm (Choristoneura fumiferana) in Minnesota, U.S.A.

2019 ◽  
Vol 49 (12) ◽  
pp. 1633-1637 ◽  
Author(s):  
Stephanie R. Patton ◽  
Matthew B. Russell ◽  
Marcella A. Windmuller-Campione ◽  
Christopher B. Edgar
Keyword(s):  
North America ◽  
Picea Glauca ◽  
Growth Response ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Forest Products ◽  
White Spruce ◽  
Diameter Growth ◽  
Native Forest ◽  
Eastern Spruce Budworm

White spruce (Picea glauca (Moench) Voss) plantations have historically been an important source of high-quality forest products in the Great Lakes Region of North America. Thinning in spruce plantations is a common silvicultural practice for reducing competition and promoting resiliency to forest health threats such as eastern spruce budworm (Choristoneura fumiferana Clemens), a native forest pest of eastern North America. Spruce budworm larvae feed on the foliage of trees, which reduces growth and potentially causes mortality during an outbreak. There has been continual spruce budworm defoliation in northern Minnesota, U.S.A., since the mid-1950s, with higher levels of defoliation in the late 1990s. This research modeled the diameter growth response of white spruce 18 years after initial thinning in stands that presently range between 44 and 64 years old. Some stands received a second thinning in recent years. We used generalized nonlinear least squares and nonlinear mixed-effects models to estimate annual diameter growth using common tree and stand metrics. Growth model performance was improved by including thinning and frequency of spruce budworm defoliation as modifiers of diameter growth. Results of this study highlight how thinning in combination with insect disturbance affect diameter growth in white spruce plantations of northern Minnesota.

Windthrow as an important process for white spruce regeneration

2002 ◽  
Vol 78 (5) ◽  
pp. 732-738 ◽  
Author(s):  
Jean-Claude Ruel ◽  
Marius Pineau
Keyword(s):  
Key Words ◽  
Picea Glauca ◽  
Abies Balsamea ◽  
White Spruce ◽  
Balsam Fir ◽  
Differential Mortality ◽  
Important Process ◽  
Mature Stands

White spruce (Picea glauca (Moench.) Voss.) is frequently found in association with balsam fir (Abies balsamea (L.) Mill.) in virgin stands. However, its regeneration is less aggressive than that of balsam fir. The persistance of white spruce in the canopy might be explained by differential mortality and windthrow. Windthrow could play an important role in creating favourable seedbeds and providing increased light. This paper examines the contribution of windthrow for white spruce regeneration in balsam fir-dominated forests. Experimental windthrows were created and regeneration establishment monitored for three seasons. Windthrow greatly modified the availability of seedbeds and enhanced white spruce establishment. Older natural windthrows were sampled to conclude that this effect was still evident more than five years after windthrow occured. We also noticed that white spruce benefited more from the disturbance than did balsam fir. Finally, sampling conducted in mature stands showed that mature white spruce stems were more abundant on the mounds created by old uprootings, indicating that this effect is maintained in the long term. Even though balsam fir also benefited from windthrow, the benefit was proportionally greater for white spruce. Key words: Picea glauca, Abies balsamea, windthrow, microtopography, regeneration

Two species in the Ceratocystis coerulescens complex from conifers in western North America

1997 ◽  
Vol 75 (5) ◽  
pp. 827-834 ◽  
Author(s):  
Michael J. Wingfield ◽  
Thomas C. Harrington ◽  
Halvor Solheim
Keyword(s):  
North America ◽  
Bark Beetle ◽  
Picea Glauca ◽  
Primary Component ◽  
Western North America ◽  
Dendroctonus Rufipennis ◽  
Engelmann Spruce ◽  
The North ◽  
Blue Stain ◽  
High Degree

Two species of Ceratocystis are described from western North America. Ceratocystis rufipenni Wingfield, Harrington, & Solheim is associated with the North American spruce bark beetle Dendroctonus rufipennis infesting both Engelmann spruce (Picea engelmannii Parry) and white spruce (Picea glauca (Moench) Voss) in British Columbia. This fungus is a primary component of the bark beetle mycota and has a relatively high degree of virulence to Engelmann spruce. Ceratocystis douglasii (Davidson) Wingfield & Harrington was previously described as Endoconidiophora coerulescens f. douglasii. It is common on Douglas-fir lumber in western North America where it causes blue stain. Both fungi grow optimally at low temperatures and produce perithecia only after extended incubation under refrigeration. Ceratocystis rufipenni produces conidiophores mostly in association with perithecia, whereas conidia and conidiophores of C. douglasii are produced abundantly on wood and agar. Key words: Ceratocystis, Chalara, Dendroctonus, Ophiostoma, bark beetle – fungus interactions, symbiosis.

Population genetic variation, structure, and evolution in Engelmann spruce, white spruce, and their natural hybrid complex in Alberta

2000 ◽  
Vol 78 (6) ◽  
pp. 768-780 ◽  
Author(s):  
Om P Rajora ◽  
Bruce P Dancik
Keyword(s):  
Genetic Variation ◽  
Picea Glauca ◽  
White Spruce ◽  
Natural Hybridization ◽  
Putative Hybrid ◽  
Species Differentiation ◽  
Engelmann Spruce ◽  
Hybrid Complex ◽  
Allozyme Loci ◽  
Putative Hybrids

Genetic variation, structure, and evolution of 12 populations of putative Engelmann spruce (Picea engelmanii Parry), white spruce (Picea glauca (Moench) Voss), and Engelmann - white spruce natural hybrids from the sympatric areas and two populations of white spruce from the allopatric areas in Alberta were examined using 23 allozyme loci coding for 13 enzymes in needles. Although most of the alleles were widespread, unique alleles were found in 9 of the 14 populations. No species-specific allele was observed. However, allele frequency differences were observed between the putative Engelmann and white spruce populations at a number of loci. Frequencies of 13 alleles showed significant correlation with altitude, those of 11 alleles showed correlation with latitude, and those of 3 alleles showed correlation with longitude. On average, 66.2% (99% criterion) of the loci were polymorphic, the number of alleles per locus was 1.88, the number of alleles per polymorphic locus was 2.88, and the observed and expected heterozygosities were 0.063 and 0.184, respectively. Genetic variability of allopatric white spruce, putative Engelmann, sympatric white spruce, and hybrid populations was quite comparable. The mean FST estimate was 0.123 for the total populations. Canonical discriminant functions separated four putative Engelmann spruce populations from the fifth putative Engelmann spruce population and from the allopatric and sympatric white spruce and sympatric putative hybrid populations. A cluster analysis from genetic distances generally separated allopatric and sympatric white spruce populations from the putative Engelmann spruce and hybrid populations. A Wagner tree of the 14 populations produced two main branches; one branch consisting of two allopatric and two sympatric white spruce and one putative hybrid populations, and another branch consisting of the remaining nine spruce populations representing putative Engelmann spruce, putative hybrids, and sympatric white spruce. Putative hybrids showed lower distances to white spruce from the canonical discriminant analysis, whereas they showed lower distances to putative Engelmann spruce from the genetic distance analysis. High allozyme genetic identities between putative Engelmann and white spruce and allelic differentiation related to altitude in Alberta suggest that Engelmann spruce could at best be considered as a subspecies of Picea glauca, with white spruce named as Picea glauca ssp. glauca and Engelmann spruce named as Picea glauca ssp. engelmannii.Key words: Picea glauca, Picea engelmannii, biosystematics, natural hybridization, species differentiation, genetic divergence.

EFFECT OF PHOTOPERIOD ON DROUGHT RESISTANCE OF WHITE SPRUCE SEEDLINGS

1960 ◽  
Vol 38 (4) ◽  
pp. 597-599 ◽  
Author(s):  
O. Vaartaja
Keyword(s):  
Drought Resistance ◽  
Picea Glauca ◽  
Day Treatment ◽  
White Spruce ◽  
The Other ◽  
Severe Drought ◽  
Drought Treatment ◽  
Short Day ◽  
Long Day ◽  
Other Hand

Seedlings of Picea glauca were grown for 2 months under three photoperiodic treatments. Short day treatment induced early terminal dormancy and resistance to severe drought treatment. Long day treatments, on the other hand, allowed prolonged growth of most seedlings and made them susceptible to drought.

The Biology of Adelges cooleyi (Gill.) (Homoptera: Phylloxeridae)

1959 ◽  
Vol 91 (10) ◽  
pp. 601-617 ◽  
Author(s):  
Margaret E. P. Gumming
Keyword(s):  
North America ◽  
Pseudotsuga Menziesii ◽  
Tree Species ◽  
Picea Glauca ◽  
Douglas Fir ◽  
Alternate Host ◽  
Shade Tree ◽  
Engelmann Spruce ◽  
Shelter Belt ◽  
Adelges Cooleyi

Adelges cooleyi (Gill.) causes galls on spruce in the forests and on shelter-belt and shade-tree plantings in Alberta. The alternate host is Douglas fir, on which the injury is less conspicuous. The tree species affected are white spruce, Picea glauca (Moench) Voss, Engelmann spruce, P. engelmanni Parry, and blue Douglas fir, Pseudotsuga menziesii (Mirb.) Franco. A. cooleyi is indigenous to North America.

Tree recruitment from burn edges

2000 ◽  
Vol 30 (8) ◽  
pp. 1264-1274 ◽  
Author(s):  
D F Greene ◽  
E A Johnson
Keyword(s):  
Picea Glauca ◽  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Basal Area ◽  
White Spruce ◽  
Picea Engelmannii ◽  
Larix Laricina ◽  
Tree Recruitment ◽  
Engelmann Spruce ◽  
Large Fires

We developed and tested a wind-dispersal model of tree recruitment into burns from living sources at the fire edge or from small unburned residual stands. The model was also tested on recruitment of serotinous Pinus banksiana Lamb. within a burn. The model assumed that source strength is proportional to basal area density and that an individual (point source) recruitment curve can be expressed as a lognormal distribution. The model made significant predictions of the recruitment curves of Engelmann spruce (Picea engelmannii Parry ex Engelm.), white spruce (Picea glauca (Moench) Voss), and balsam fir (Abies balsamea (L.) Mill.) to distances as great as 2.0 km, although it tended to underpredict Abies and overpredict Picea. The model gave significant prediction of recruitment for jack pine (Pinus banksiana) within burns with seeds derived from aerial seed banks, and of white spruce and tamarck (Larix laricina (Du Roi) K. Koch) up to 100 m from residual stands. By forestry standards, burns are poorly stocked by those species that must obligately recruit from edges. In large fires, adequate stocking by a species such as white spruce that had 5 m2/ha of basal area would be limited to about 70 m from the edge. Small residual stands are expected to supply about half of all the recruits of white spruce or fir at distances exceeding about 800 m from a nominal burn edge.

SPRUCE CONE INSECTS IN BRITISH COLUMBIA AND THEIR CONTROL

1973 ◽  
Vol 105 (1) ◽  
pp. 113-122 ◽  
Author(s):  
A. F. Hedlin
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Black Spruce ◽  
Gall Midge ◽  
White Spruce ◽  
Important Species ◽  
Systemic Insecticides ◽  
Engelmann Spruce ◽  
Cone Axis ◽  
Considerable Loss

AbstractInsects cause considerable loss of seed in white spruce, Picea glauca (Moench) Voss, and Engelmann spruce, P. engelmannii Parry, in British Columbia. The most important species are a maggot, Hylemya anthracina (Cz.), and a seed moth, Laspeyresia youngana (Kit.). Other insects are: a seed chalcid, Megastigmus piceae Roh., a cone axis midge, Dasineura rachiphaga Tripp, a gall midge, D. canadensis Felt, a seed midge, Mayetiola carpophaga Tripp, and a scale-feeding midge. These insects also occur in cones of Sitka spruce, P. sitchensis (Bong.) Carr., and black spruce, P. mariana (Mill.) BSP.The systemic insecticides dimethoate and formothion proved to be effective against these insects when applied as sprays following pollination in mid-June.

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