Ecological genetics of Pinuscontorta in the Wasatch and Uinta Mountains of Utah

1985 ◽  
Vol 15 (3) ◽  
pp. 524-530 ◽  
Author(s):  
G. E. Rehfeldt
Keyword(s):  
Regression Models ◽  
Laboratory Tests ◽  
Cold Hardiness ◽  
Geographic Location ◽  
Shoot Elongation ◽  
Ecological Genetics ◽  
Growth Potential ◽  
Uinta Mountains ◽  
Population Means ◽  
Seed Transfer

Genetic differentiation of 45 populations of Pinuscontorta primarily from the Wasatch and Uinta Mountains was studied in field, greenhouse, and laboratory tests. Analyses of variables reflecting growth potential, morphology, cold hardiness, and periodicity of shoot elongation revealed population differentiation for a variety of traits. Regression models related as much as 77% of the variance among population means to the elevation and geographic location of the seed source. For genetic variation to be arranged along relatively steep environmental clines implies pronounced adaptive differentiation. As a result, seed transfer in reforestation should be restricted severely if maladaptation is to be controlled.

A model of genetic variation for Pinus ponderosa in the Inland Northwest (U.S.A.): applications in gene resource management

1991 ◽  
Vol 21 (10) ◽  
pp. 1491-1500 ◽  
Author(s):  
G. E. Rehfeldt
Keyword(s):  
Genetic Variation ◽  
Pinus Ponderosa ◽  
Regression Models ◽  
Common Garden ◽  
Shoot Elongation ◽  
The United States ◽  
Independent Data ◽  
Gene Conservation ◽  
Seed Transfer ◽  
Inland Northwest

Models were developed to describe genetic variation among 201 seedling populations ofPinusponderosa var. ponderosa in the Inland Northwest of the United States. Common-garden studies provided three variables that reflected growth and development in field environments and three principal components of six variables that reflected patterns of shoot elongation. Regression models were developed for describing genetic variation across the landscape. Using functions of latitude, longitude, and elevation as descriptors, these models produced values of R2 that were as large as 0.66, while averaging 0.39. The models described genetic variation as occurring along relatively steep elevational clines and gentle geographic (i.e., latitudinal and longitudinal) clines. An exercise at validating the models with independent data supported their veracity. Predictions made by the models are applied to limiting seed transfer, designing breeding zones, planning gene conservation programs, interpreting phenotypic variation, and predicting the effects of environmental change on the adaptedness of populations.

Ecological adaptations in Douglas-fir (Pseudotsugamenziesii var. glauca) populations. III. Central Idaho

1983 ◽  
Vol 13 (4) ◽  
pp. 626-632 ◽  
Author(s):  
Gerald E. Rehfeldt
Keyword(s):  
Cold Hardiness ◽  
High Growth ◽  
Frost Damage ◽  
Douglas Fir ◽  
Growth Potential ◽  
Bud Burst ◽  
Population Means ◽  
Spring Frost ◽  
Selection For ◽  
Central Idaho

Growth, phenology, and cold hardiness of seedlings from 74 populations of Douglas-fir (Pseudotsugamenziesii var. glauca (Beissn.) Franco) from central Idaho were compared in four contrasting environments. Analyses of 3-year-old seedlings revealed population differentiation for eight variables: bud burst, bud set, multiple flushing, height, deviation from regression of 3-year height on 2-year height, spring frost damage, fall frost damage, and winter injury. These analyses, as well as high intercorrelations among population means, suggested that adaptations result from a balance between selection for a high growth potential in mild environments and selection for cold hardiness in severe environments. Consequently, genetic variation among populations was closely related to the elevation, geography, and climate of the seed source.

Adaptation of Picea engelmannii populations to the heterogeneous environments of the Intermountain West

1994 ◽  
Vol 72 (8) ◽  
pp. 1197-1208 ◽  
Author(s):  
Gerald E. Rehfeldt
Keyword(s):  
Genetic Variation ◽  
Regression Models ◽  
Cold Hardiness ◽  
Ecological Genetics ◽  
Picea Engelmannii ◽  
Heterogeneous Environments ◽  
Intermountain West ◽  
Morphometric Characters ◽  
Blue Spruce ◽  
Engelmann Spruce

Seedlings from 104 natural populations of Engelmann spruce (Picea engelmannii) and 10 blue spruce (Picea pungens) populations from the Intermountain West, U.S.A., were compared in common gardens. Comparisons involved 16 characters that described growth, development, and cold hardiness plus nine monoterpenes. Canonical discriminant analyses detected one population of blue spruce that had been misidentified, readily separated populations of blue and Engelmann spruce, suggested that three Southwest populations differed markedly from Intermountain populations of Engelmann spruce, but identified no Intermountain populations that reflected introgression with blue spruce. Genetic differences were detected among populations of Engelmann spruce for 16 of the morphometric characters, and multiple regression models accounted for as much as 70% of the variance among populations. The regressions described genetic variation occurring along clines that were dominated by elevational and latitudinal effects. The slope of the clines, however, was relatively gentle; populations located within the same physiographic province must be separated by at least 420 m in elevation before genetic differentiation becomes a reasonable possibility. By providing a means for assessing the degree by which similar genotypes recur across the landscape, the regression models have direct practical application in programs ranging from land management to conservation biology. Key words: population differentiation, genetic variation, ecological genetics.

Mapping genetic variation and seed zones for Bromus carinatus in the Blue Mountains of eastern Oregon, USAIn this article, mention of companies or trade names does not constitute an endorsement of any product or procedure.

Botany ◽  
2010 ◽  
Vol 88 (8) ◽  
pp. 725-736 ◽  
Author(s):  
R. C. Johnson ◽  
Vicky J. Erickson ◽  
Nancy L. Mandel ◽  
J. Bradley St Clair ◽  
Kenneth W. Vance-Borland
Keyword(s):  
Environmental Variables ◽  
Regression Models ◽  
Plant Traits ◽  
Seed Source ◽  
Maximum Temperature ◽  
Blue Mountains ◽  
Seed Transfer ◽  
Bromus Carinatus ◽  
Seed Zones ◽  
Transfer Zones

Seed transfer zones ensure that germplasm selected for restoration is suitable and sustainable in diverse environments. In this study, seed zones were developed for mountain brome ( Bromus carinatus Hook. & Arn.) in the Blue Mountains of northeastern Oregon and adjoining Washington. Plants from 148 Blue Mountain seed source locations were evaluated in common-garden studies at two contrasting test sites. Data on phenology, morphology, and production were collected over two growing seasons. Plant traits varied significantly and were frequently correlated with annual precipitation and annual maximum temperature at seed source locations (P < 0.05). Plants from warmer locations generally had higher dry matter production, longer leaves, wider crowns, denser foliage, and greater plant height than those from cooler locations. Regression models of environmental variables with the first two principal components (PC 1 and PC 2) explained 46% and 40% of the total variation, respectively. Maps of PC 1 and PC 2 generally corresponded to elevation, temperature, and precipitation gradients. The regression models developed from PC 1 and PC 2 and environmental variables were used to map seed transfer zones. These maps will be useful in selecting mountain brome seed sources for habitat restoration in the Blue Mountains.

scholarly journals A case of severe frost damage prior to budbreak in young conifers in Northeastern Ontario: Consequence of climate change?

2009 ◽  
Vol 85 (3) ◽  
pp. 453-462 ◽  
Author(s):  
Rongzhou Man ◽  
Gordon J Kayahara ◽  
Qing-Lai Dang ◽  
James A Rice
Keyword(s):  
Climate Change ◽  
Cold Hardiness ◽  
Shoot Elongation ◽  
Frost Damage ◽  
Weather Data ◽  
Climatic Warming ◽  
Closed Canopy ◽  
Time Requirements ◽  
Spring Frosts ◽  
Understory Trees

In spring 2007, young planted and natural conifers suffered extensive needle and bud injury near Hearst and Kapuskasing in northeastern Ontario. Damage was observed on all species of conifers up to 20 years old and 8 m in height. Taller trees, especially those in the overstory, and young understory trees protected by a closed canopy had less damage. The damage was caused by earlier than normal loss of cold hardiness followed by late spring frosts according to damage observations, weather station data, and calculated thermal time requirements for budbreak and cold hardiness of conifers. During May 19 to 21, 2007, minimum temperatures were recorded between -8°C and -9°C, and before this period, temperatures were warm enough to induce early dehardening and loss of trees' cold hardiness. According to the historical weather data for Kapuskasing, estimated budbreak time has become earlier since 1918 and freezing temperatures during budbreak and shoot elongation (between growing degree days 100 and June 15) have become more frequent since 1980. If the trend towards earlier budbreak is due to climate change, then the type of frost damage we observed in northeastern Ontario in 2007 could become more common. We discuss implications of such events and suggest research needed to understand the risk of frost damage with climatic warming and to reduce damage. Key words: conifer frost damage, mature needle and bud (or needle/bud) mortality, early dehardening and budbreak (or dehardening/budbreak), climatic warming

Shoot morphology and shoot growth potential in 1-year-old Scots pine seedlings

1981 ◽  
Vol 11 (4) ◽  
pp. 789-795 ◽  
Author(s):  
S. Thompson
Keyword(s):  
Scots Pine ◽  
Shoot Growth ◽  
Growing Season ◽  
Shoot Elongation ◽  
Growth Potential ◽  
Shoot Morphology ◽  
Growing Seasons ◽  
Pine Seedlings

When seedlings of a single seed source of Scots pine (Pinussylvestris L.) were raised for 26 weeks in a naturally lit, heated greenhouse, two types of shoot morphology were observed. Type 1 was that normally found in 1-year-old seedlings. Type 2 had a shoot morphology similar to that of seedlings raised outdoors for two growing seasons. When compared with type 1 plants, type 2 plants had an earlier start to shoot elongation, set their buds earlier, and stopped shoot elongation sooner. After one growing season, type 2 plants were shorter, had fewer stem units for shoot elongation in the second season, but carried a greater foliage biomass than 1-year-old type plants. After two seasons they remained shorter. Thus, plant rearing practices which result in the production of seedlings with this type of shoot morphology arc undesirable.The relationship between early "budsct," shoot morphology, and plant height suggests that the proportion of seedlings with a 2-year-old shoot morphology after one growing season in a heated greenhouse may be used as an early test for height growth potential in seed origins and possibly in progenies of north temperate pine species.

Intake of milk and pasture and growth rate of calves reared by cows with high or low potential for milk production

2018 ◽  
Vol 58 (3) ◽  
pp. 523 ◽  
Author(s):  
F. J. Roca Fraga ◽  
N. Lopez-Villalobos ◽  
N. P. Martin ◽  
P. R. Kenyon ◽  
S. T. Morris ◽  
...  
Keyword(s):  
Growth Rate ◽  
Total Energy ◽  
Energy Intake ◽  
Milk Production ◽  
Regression Models ◽  
Milk Intake ◽  
Growth Potential ◽  
Random Regression ◽  
Economic Return ◽  
Holstein Friesian

Milk production of cows influences calf weaning weight, which is the major driver for economic return in a cow–calf operation. The growth trajectory of 64 steer calves resulting from a terminal cross between Angus or Simmental bulls with Angus, Angus cross Holstein Friesian, Angus cross Jersey and Angus cross KiwiCross cows was examined during the pre-weaning period from birth (D0) to weaning (D148) and during the post-weaning period until a year of age (D365). Random regression models were used to model milk intake and liveweight of calves throughout lactation. These models were a good fit to the data (r2 = 0.77 for milk intake and r2 = 0.99 for liveweight). Total energy intake from milk was greater (P < 0.05) for the Angus cross Holstein Friesian-, Angus cross Jersey- and Angus cross KiwiCross-reared steers than for those reared by Angus dams. Additional milk intake increased liveweight of steers from D90 to D365, but the magnitude of the effect decreased as the calves aged. Simmental-sired steers had a greater liveweight response to additional milk intake than Angus-sired steers at D120 and D148, probably reflecting greater growth potential from out-crossed calves.

Utilizing regression models to find functions for determining ripping production based on laboratory tests

Measurement ◽  
2017 ◽  
Vol 111 ◽  
pp. 216-225 ◽  
Author(s):  
Edy Tonnizam Mohamad ◽  
Danial Jahed Armaghani ◽  
Amir Mahdyar ◽  
Ibrahim Komoo ◽  
Khairul Anuar Kassim ◽  
...  
Keyword(s):  
Regression Models ◽  
Laboratory Tests ◽  
Ripping Production

scholarly journals Development of a scientific study for accessing the criteria under Commission Regulation (EC) 2073/2005 on traditional Slovak sheep cheese "bryndza"

2011 ◽  
Vol 29 (No. 1) ◽  
pp. 31-34
Author(s):  
L. Cabanová ◽  
O. Škuntová ◽  
D. Matisová ◽  
M. Pipová
Keyword(s):  
Listeria Monocytogenes ◽  
Shelf Life ◽  
Laboratory Tests ◽  
Growth Potential ◽  
Life Study ◽  
Physico Chemical ◽  
Commission Regulation ◽  
The Difference ◽  
Microbiological Analyses ◽  
Positive Results

A scientific shelf-life study for Listeria monocytogenes in the typical Slovak cheese "bryndza" was performed in accordance with the requirements of the Commission Regulation (EC) 2073/2005. Based on the previous positive findings of L. monocytogenes in the final products, the producer decided to perform laboratory tests, the results of which would allow him a different evaluation of these positive results. Both the physico-chemical (pH, a<sub>w)</sub> and microbiological examinations of "bryndza" cheese stored at 5.8&ndash;6.2&deg;C were performed every two days till the end of the product shelf-life (7 days). Microbiological analyses were performed after artificial contamination of the final product with a mixture of three L. monocytogenes strains. The growth potential of L. monocytogenes was calculated as the difference in the counts of this bacterium between the last day and the first day of the test. The Slovak traditional "bryndza" cheese has been found not to support the growth of L. monocytogenes. Thus, the counts of L. monocytogenes must not exceed 50 CFU/g at the beginning and 20 CFU/g at the end of the product shelf-life in order to ensure its safety for the consumer.

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