Genetic diversity of yellow birch seedlings in Michigan

1977 ◽  
Vol 55 (22) ◽  
pp. 2778-2788 ◽  
Author(s):  
Kenneth A. Wearstler Jr. ◽  
Burton V. Barnes

The objective of the study was to determine genetic differentiation of populations of yellow birch (Betula alleghaniensis Britton) along ecological gradients in Michigan and the Appalachian Mountains. Seeds were collected from populations in each of six physiographic regions of Michigan and in the northern and southern Appalachian Mountains. Seedlings were grown in a common garden in southeastern Michigan. First-year height of progeny, seed weight, initial germination, and germination percentage for 141 yellow birch trees in 30 populations were determined and compared.Significant differences were found among the six Michigan regions for all characters. Strong south–north clinal trends of decreasing height, increasing seed weight, earlier initial germination, and increasing total germination were revealed. Comparisons between physiographic regions showed that tall seedlings were produced by relatively light, late-germinating seeds. Within each region, however, seedlings from earlier germinating seeds tended to exhibit greater height growth. Significant differences were found among populations within a given region for specific characters. In the Appalachian Mountains, southern populations had taller progeny and lighter and poorer germinating seeds than northern populations.Regressions relating each character to 13 site variables were computed. Variation in total height and initial germination were interpreted as the result of differences in the length of the growing season associated with changes in elevation, terrain type, and aspect. Variation in seed weight was associated with differences in the length of growing season and soil moisture regimes.

1992 ◽  
Vol 70 (3) ◽  
pp. 562-567 ◽  
Author(s):  
Marguerite Kane ◽  
Paul B. Cavers

Three plants from each of 10 populations of the black biotype of proso millet (Panicum miliaceum) were grown in a common garden in London, Ontario. Seeds were collected from individual plants as they ripened. Each seed was identified as to location on the plant and weighed separately. Mean seed weight decreased over the growing season, both on individual inflorescences and on entire plants. Despite this trend, seeds at the upper end of the weight range were produced throughout the season. The decline in the mean resulted from an increasing proportion of smaller seeds. There was also increased variability in seed weight later in the growing season. In subsequent germination tests there was no discernable relationship between total percent viability and date of seed ripening. Total percent viability was above 70% for each sampling date. Key words: seed weight, positional effects, proso millet, germination, seasonal variation.


2010 ◽  
Vol 40 (3) ◽  
pp. 423-435 ◽  
Author(s):  
Charles R. Drever ◽  
James Snider ◽  
Mark C. Drever

Our objective was to assess the relative rarity and representation within protected areas of Standard Forest Units (SFUs) in northeastern Ontario by applying the concepts of geographic range, habitat specificity, and local population size. SFUs are stand type classifications, routinely employed by forest managers, based on tree composition, disturbance history, and prescribed silvicultural system. We identified several SFUs as rare because of a narrow distribution, association with only one landform type, or lack of at least one stand larger than an ecoregion-specific threshold. In the Boreal forest, rare SFUs comprised stands dominated by eastern hemlock ( Tsuga canadensis (L.) Carrière), red oak ( Quercus rubra L.), yellow birch ( Betula alleghaniensis Britt.), or eastern white-cedar ( Thuja occidentalis L.). Rare SFUs also included eastern white pine ( Pinus strobus L.) and (or) red pine ( Pinus resinosa Ait.) leading stands managed by shelterwood or seed tree silviculture as well as low-lying deciduous stands and selection-managed stands of shade-tolerant species. In the Great Lakes – St. Lawrence forest, rare SFUs were yellow birch stands, stands dominated by conifer species abundant in the Boreal, and shelterwood-managed hardwood stands. Several rare SFUs had <12% of their total area in protection, i.e., stands dominated by eastern white pine, yellow birch, eastern white pine – red oak, or eastern white-cedar. These rare stand types require increased protection in reserves and tailored silvicultural practices to maintain their probability of persistence.


2013 ◽  
Vol 89 (04) ◽  
pp. 512-524 ◽  
Author(s):  
Martin Béland ◽  
Bruno Chicoine

We examined applicability of various partial cutting systems in order to regenerate tolerant hardwood stands dominated by sugar maple (Acer saccarhum), American beech (Fagus grandifolia) and yellow birch (Betula alleghaniensis) on northern New Brunswick J.D. Irving Ltd. freehold land. Sampling of 1065 one-m2 plots in 31 stands managed by selection cutting, shelterwood method and strip or patch cutting and in six control stands allowed a 15-year retrospective study of natural regeneration in stands of low residual densities and with minimal soil disturbance and no control of competing vegetation. Beech regeneration was most abundant in the patch cuts, yellow birch in shelterwood stands and sugar maple in the selection system areas. Results suggest that initial stand conditions influence the composition of the regeneration more than the prescribed treatment. At the stand scale (a few hectares), sugar maple recruitment was positively influenced by its proportion in the initial stand, and negatively by the cover of herbs and shrubs. Yellow birch regeneration was mainly affected by shrub competition. At the plot (1 m2) scale, mineral soil and decayed wood substrates and ground-level transmitted light were determinant factors for yellow birch regeneration. Beech-dominated stands were likely to regenerate to beech. A dense beech sucker understory was promoted in harvested patches. Areas with dense understory of American beech, shrubs, or herbs require site preparation to reduce interference either before or at the time of partial cutting. Shelterwood seed cutting and selection cutting should leave a residual of 12 m2/ha and 17 m2/ha respectively in seed trees uniformly distributed.


2021 ◽  
Vol 2 (1) ◽  
pp. 131-140
Author(s):  
Yousif M. Fattah ◽  
Ali H. Omer

Glyphosate is a broad-spectrum herbicide used mostly in crops. This study looked at the genotoxic and Glyphosate has a cytotoxic effect on Allium cepa. As toxicity markers, the Mitotic index, chromosomal aberrations, formations of Micronucleus, germination percentage, root duration, and seed weight were used. Allium cepa seeds were afflicted with distinct concentrations (0.5, 1.0, 2.0 and 4.0 ml/l) of Glyphosate for 24 h treatment periods. The results reveal that pesticide Glyphosateis capable to reduce root growth and causes chromosomal aberrations;consisting of an anaphase bridge, ring chromosome, binucleated cells, multipolarity, Fragment chromosome, vagrant chromosome, chromatid gaps, star anaphase. With increasing Glyphosate concentration, the mitotic index decreased rapidly. In conclusion, our findings indicate that used pesticidemay be toxic to living organism.


2017 ◽  
Vol 9 (8) ◽  
pp. 229 ◽  
Author(s):  
Nigusie Girma ◽  
Asnake Fikre ◽  
Chris O. Ojiewo

Development of irrigation-based chickpea production is considered the most important alternative approach in combating climate change and maximizing productivity, especially in moisture-stress areas and in areas where water and land for irrigation is available. In central Ethiopia, where production of chickpea (especially Kabuli type) is becoming an important part of agriculture, although many superior varieties (both desi and Kabuli types) are available, they have been evaluated and released based on rainfed production. Hence, there is an urgent need for evaluation of varieties suited for irrigation-based production. Towards this goal, during the 2012/13 growing season, 14 Kabuli genotypes (previously introduced) and 24 desi genotypes (nurseries obtained from ICRISAT) were evaluated independently at three and one locations respectively (Kabuli at Debre Zeit, Ambo and Werer; desi at Debre Zeit) for production adaptation under irrigation. The parameters evaluated were date of maturity, 100-seed weight and yield. Overall, while most Kabuli genotypes showed high adaptability to irrigation-based production at all locations, four Kabuli genotypes (X96TH-52-14/2000 = 106.7DAS, FLIP-02-39C = 107DAS, X98TH-51-1-3 = 107.9DAS and ICCV-07313 = 107DAS) were found to be earlier in maturity; two genotypes (ICCV-07313 = 42.5 g and ICCV-04305 = 37.8 g) were identified as having high 100-seed weight and one genotype (ICCV-05309 = 3228.8 kg/ha or 32 quintals/ha) out yielded all genotypes across locations. The result of combined analysis indicated five promising genotypes showing more than 20 kg/ha yield on average. All desi varieties showed maturity dates of under four months; six genotypes showed higher 100-seed weight and eight genotypes showed promising yield responses (> 2000 kg/ha). From these preliminary results, it can be deduced that irrigation can play a significantly complementary role to the rainfed system, provided the genetics by management is optimized through research and innovation.


1976 ◽  
Vol 56 (3) ◽  
pp. 487-491 ◽  
Author(s):  
S. SMOLIAK ◽  
A. JOHNSTON

Forage and seed yield, percentage seed germination, speed of germination index, and 1,000-seed weight were determined for a population of 170 plants selected from Oxley cicer milkvetch (Astragalus cicer L.). Seedlings from open-pollinated seed from the selected plants were measured for leaf weight and leaf area, and specific leaf weight was calculated. Most of the characters studied were asymmetrical in distribution. The correlation coefficient between forage and seed yields of mature plants was positive and highly significant. Seedling leaf weight was positively and closely related to seedling leaf area, but seedling leaf area was a more reliable indicator of photosynthetic efficiency. The variability in the characters studied in the selected population suggests that further improvement in forage yield, germination percentage, speed of germination, and seedling vigor may be obtained through a breeding program.


1964 ◽  
Vol 42 (6) ◽  
pp. 1270-1281 ◽  
Author(s):  
A. J. Nanassy

Electric polarization spectra of oven-dry yellow birch (Betula alleghaniensis Britt.) were measured over the range of frequencies from 50 kc/s to 50 Mc/s and temperatures from 20° to 100 °C. These observations, which provide only a section of the total dispersion and relaxation absorption spectra of the material, give information on the general variation of the dispersion curve with frequency, temperature, and grain orientation to the electric field, and indicate that the total spectra spread over a wide frequency range, probably from 0 c/s to a few Gc/s and include several absorption peaks and dispersion curves.


2008 ◽  
Vol 38 (3) ◽  
pp. 488-497 ◽  
Author(s):  
Marie-Lou Lefrançois ◽  
Marilou Beaudet ◽  
Christian Messier

Crown openness (CO) of mature trees influences light transmission within the forest canopy. However, in modeling, this variable is often considered constant within species, and its potential regional variability is ignored. The objective of this study was to evaluate if CO values of yellow birch ( Betula alleghaniensis Britt.), sugar maple ( Acer saccharum Marsh.), and eastern hemlock ( Tsuga canadensis (L.) Carrière) vary according to the following factors: (i) species, (ii) regional actual evapotranspiration (AET), (iii) tree size (i.e., diameter at breast height, DBH), and (iv) angle of transmission from zenith. To achieve this, CO was evaluated for 136 yellow birches, 109 sugar maples, and 68 hemlocks from different regions of western Quebec, southern Ontario, and northern Michigan. Results showed that all of the studied factors affected CO. While dominant trees can intercept light laterally as well as vertically, smaller trees are more efficient at intercepting light vertically. Increasing AET is associated with more open crowns. Given its importance in light transmission in the understory, a better understanding of how CO varies between individuals, species, and regions is needed.


Holzforschung ◽  
2006 ◽  
Vol 60 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Jean-Michel Lavoie ◽  
Tatjana Stevanovic

Abstract The lipophylic extracts of yellow birch (Betula alleghaniensis) have been investigated to detect the effect of tree age and wood storage time on extract composition. A total of 17 wood disks were cut from trees belonging to different age groups at 1 m above ground and the wood was milled as usual for extraction (laboratory samples). In addition, 49 sawdust samples were collected in a lumber mill to study the effect of industrial processing on the extractives (industrial samples). All laboratory and industrial samples were extracted with dichloromethane under sonication. The chemical composition of the lipophilic extracts obtained was analyzed by GC-MS. A systematic (quasi-linear) relationship was found between the lipophilic extract yield and specimen age. A total of 30 constituents from yellow birch extracts have been identified, 26 of which have never been previously reported for B. alleghaniensis wood.


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