Variance in flushing among and within stands of seedling white spruce

1979 ◽  
Vol 9 (4) ◽  
pp. 517-521 ◽  
Author(s):  
D. F. W. Pollard ◽  
C. C. Ying

Early, rapid tests are required to ascertain the structure of white spruce Piceaglauca (Moench) Voss populations of southeastern Ontario, where valuable but limited seed sources have been located through field trials. As a significant phenological character associated with growth and hardiness, rate of flushing was monitored under controlled environments in six half-sib families from each of four stands of white spruce located in southeastern Ontario. Whereas no significant variation occurred among stands, highly significant differences occurred among families within stands throughout the flushing period. Results are interpreted as a reflection of coadaption of populations to the timing of environmental hazards. A comparison is made with the minor geographic and pronounced annual variations in occurrence of last spring frost.

2000 ◽  
Vol 80 (2) ◽  
pp. 247-253 ◽  
Author(s):  
K. G. Briggs ◽  
G. J. Dunn

Information is lacking concerning the extent of variability in Canadian six-row barley cultivars for differences in potential field germination vigour and other germination characteristics, and the extent to which these traits can be predicted from laboratory tests. This study was conducted to evaluate the extent to which a genetically diverse range of Western Canadian six-row barley cultivars differ in germination resistance and early seedling vigour or emergence rate under controlled environments and in the field, over a range of temperature stress conditions. Vigour was assessed by measuring germination rate, emergence rate, and dry weight accumulation in young seedlings, in the growth cabinet and in the field. Cultivars studied were selected to represent a wide range of genetic diversity typical of Canadian breeding programs of the early 1980s. Growth cabinet assays were conducted at six temperatures from 2.5 to 20 °C. Field trials were conducted using the same cultivars seeded at three dates per site in 2 yr, to assess cultivar emergence rates and seedling dry weight accumulation over a range of seedbed temperatures, using two seed sources from cultivar increases each grown in different years.Cultivars differed significantly for germination resistance in the growth cabinet, and the performance of cultivars was relatively consistent across assay temperatures and for the two different seed sources. Differences among cultivars in growth for seedling dry weight were also consistent across temperatures, but cultivar performance for seedling dry weight accumulation was not significantly correlated with germination resistance in the cabinet test. In field trials, days to emergence were highly and significantly correlated with germination resistance determined in the growth cabinet. Germination resistance was less strongly correlated with dry weight accumulation in the field at 5 wk. Across cultivars, seedling dry weight estimates in the field were significantly correlated with seedling dry weights assayed in the growth cabinet. Results from this study confirm that genetic variation in potential germination rate and seedling vigour in the field can be identified in six-row barley using the germination resistance assay in the growth cabinet. Germination resistance identified more cultivar differences than were found for the seedling dry weight accumulation tests, which were characterized by high coefficients of variation and low correlation between growth cabinet and field. Key words: Temperature, field seedling vigour, barley cultivars, prediction tests


2017 ◽  
Vol 47 (11) ◽  
pp. 1538-1545 ◽  
Author(s):  
Carolyn C. Pike ◽  
James C. Warren ◽  
Rebecca A. Montgomery

Climate change is expected to increase winter temperatures in boreal climates. White spruce (Picea glauca (Moench) Voss) is vulnerable to spring frost damage due to its habit of early budbreak, which may be exacerbated or lessened with increasingly warm winters at its southern range edge. We tested the effects of episodic warming during the quiescent stage on budbreak time and growth of seven seed sources grown in a common garden setting in Minnesota, USA. Treatment plots were warmed with infrared lamps for 4 days each in February, March, or February and March to simulate a midwinter thaw. Control plots for each treatment and an overall control were included for comparison. Trees warmed in February experienced a slight delay in spring budbreak, but differences in budbreak time were generally not significant. Terminal growth was significantly and negatively correlated with time of budbreak but not with time to growth cessation. Our results suggest that white spruce is relatively resilient to the effects of intermittent warming but that warming early in the season may delay budbreak time, which is expected to reduce terminal growth.


Author(s):  
Anna Langstroff ◽  
Marc C. Heuermann ◽  
Andreas Stahl ◽  
Astrid Junker

AbstractRising temperatures and changing precipitation patterns will affect agricultural production substantially, exposing crops to extended and more intense periods of stress. Therefore, breeding of varieties adapted to the constantly changing conditions is pivotal to enable a quantitatively and qualitatively adequate crop production despite the negative effects of climate change. As it is not yet possible to select for adaptation to future climate scenarios in the field, simulations of future conditions in controlled-environment (CE) phenotyping facilities contribute to the understanding of the plant response to special stress conditions and help breeders to select ideal genotypes which cope with future conditions. CE phenotyping facilities enable the collection of traits that are not easy to measure under field conditions and the assessment of a plant‘s phenotype under repeatable, clearly defined environmental conditions using automated, non-invasive, high-throughput methods. However, extrapolation and translation of results obtained under controlled environments to field environments is ambiguous. This review outlines the opportunities and challenges of phenotyping approaches under controlled environments complementary to conventional field trials. It gives an overview on general principles and introduces existing phenotyping facilities that take up the challenge of obtaining reliable and robust phenotypic data on climate response traits to support breeding of climate-adapted crops.


2010 ◽  
Vol 86 (3) ◽  
pp. 348-353 ◽  
Author(s):  
Ali A Rahi ◽  
Colin Bowling ◽  
Dale Simpson

Survival, total height and diameter at breast height (DBH) were measured in the fall of 2005 in a 48-year-old red pine (Pinus resinosa Ait.) provenance trial growing in northwestern Ontario. There was significant variation in both height and diameter among the 23 provenances. Generally, westerly provenances performed well while those from the Maritime Provinces exhibited relatively poor growth. Considering that the plantation is at the northern biological range of red pine, survival was high, averaging 96% after 48 years. Provenances with the best growth rates exceeded a volume of 420 m3 ha-1. Some provenances from Minnesota and Wisconsin as well as Fort Frances, Ontario exhibited superior growth and should be considered as seed sources for future planting programs in northwestern Ontario. Key words: red pine, provenance test, survival, diameter, height, volume, Northwestern Ontario


1979 ◽  
Vol 9 (4) ◽  
pp. 443-448 ◽  
Author(s):  
D. F. W. Pollard ◽  
C. C. Ying

Newly germinated seedlings of 66 open-pollinated white spruce Piceaglauca (Moench) Voss families from 11 native stands in southeastern Ontario were investigated for responses to declining photoperiod under controlled environments. Amount of height increment (free growth) during a period of declining photoperiod was studied. Variation in duration of free growth was found mostly associated with the family-within-stand component. The stand effect was negligible and decreased as seedlings aged. Lack of stand differentiation suggests that white spruce stands in. southeastern Ontario may have originated from the same base population. High genetic variation at the family level may reflect an adaptive strategy to cope with the extremely variable local climate.


1972 ◽  
Vol 2 (1) ◽  
pp. 62-63 ◽  
Author(s):  
J. R. Clements ◽  
J. W. Fraser ◽  
C. W. Yeatman

Unopened buds of white spruce (Piceaglauca (Moench) Voss) were damaged by late spring frost. At time of death of the apical meristem the buds were not ready for flushing. As expected on the basis of ground frosts, there was more damage among shorter trees than among taller trees, and more damage among open-grown trees than among understory trees.


1994 ◽  
Vol 24 (11) ◽  
pp. 2222-2234 ◽  
Author(s):  
Marek J. Krasowski ◽  
John N. Owens

The daytime pattern of mitotic index (MI) (percent of apical cells undergoing mitosis) in the shoot apex of Piceaglauca (Moench) Voss (white spruce) containerized seedlings was examined and compared for five cultural treatments. From sowing in March until mid-July, all seedlings were grown under an extended, 23-h photoperiod in a common nursery culture. In mid-July, an array of photoperiod treatments was created, ranging from ambient photoperiod and temperature to different levels of short day length and ambient or controlled, constant temperature. Consistency of MI comparisons among the treatments at different specimen collection times was emphasized rather than treatment effects on MI. Specimens were collected four times a day on two dates: when most seedlings in all treatments were initiating bud scales and when most seedlings were initiating leaf primordia. Patterns of MI were different on each of these dates. It is shown that conclusions about treatment effects on MI can be influenced by the sampling protocol and analytical approach. End of the growing season studies of white spruce and P. glauca × Piceasitchensis (Bong.) Carr. (white × Sitka spruce hybrid) seedlings grown in a greenhouse culture showed that MI below 1% was well correlated with low (<25%) foliage damage, reasonably correlated with stem tissue damage, and not correlated with bud damage resulting from controlled freezer tests to −18 °C. It is concluded that the MI technique could be useful in lifting-date determination, but different MI thresholds must be established for southern, northern, or coastal seed sources. Monitoring MI was not a good alternative to using days to bud break (testing under forcing conditions) to determine bud dormancy status. However, mitotic reactivation of the apical meristem in seedlings overwintering in a nursery bed occurred earlier in the spring than visible signs of growth reactivation (bud swelling and bud break). Studies of growth resumption of western red cedar (Thujaplicata Donn) seedlings in winter revealed that this species would be considered quiescent if tested under a long photoperiod, while under a short photoperiod growth resumption was much slower in early than in mid- and late winter.


1989 ◽  
Vol 19 (7) ◽  
pp. 832-841 ◽  
Author(s):  
C. C. Ying ◽  
C. Thompson ◽  
L. Herring

Thirty provenances of lodgepole pine (Pinuscontorta Dougl.) test stock raised at two nurseries, Cowichan Lake (coastal British Columbia) and Red Rock (interior British Columbia), were assessed in two 15-year field trials. Analyses indicated three broad geographic regions of genetic differentiation in British Columbia: coast, coast–interior transition, and central and southern interior. Provenance elevation was found to have a strong influence on growth. The results suggest that the present seed transfer guidelines for lodgepole pine in the interior region of this province are conservative enough to prevent the use of maladapted seed sources. Nursery effect declined over a period of 15 years, while provenance differences increased with the age of the trials. Interactions between provenances and sites also increased after age 9. This suggests that the effect due to seedling culture and environment in the nursery is short-term relative to the influence of the genetic component. Nursery growth was generally not a good predictor of provenance field performance.


1991 ◽  
Vol 21 (5) ◽  
pp. 707-712 ◽  
Author(s):  
Glenn R. Furnier ◽  
Michael Stine ◽  
Carl A. Mohn ◽  
Merlise A. Clyde

Variation in height at ages 9 and 19 years and at six polymorphic allozyme loci was examined for 22 seed sources (populations) in a range-wide white spruce (Piceaglauca (Moench) Voss) provenance test planted in Minnesota. There were strong differences among populations for height, with 48.0 and 54.1 % of the genetic variation for height at ages 9 and 19, respectively, due to differences among populations. Mean observed and expected estimates of allozyme heterozygosity were 0.306 and 0.290, respectively, with little deviation from genotype frequencies expected under a Hardy–Weinberg equilibrium. In contrast with the height data, an average of only 3.8% of this variation was due to differences among populations. Geographic trends were apparent in the height data, with northern and western sources performing the poorest. Neither univariate nor multivariate analyses revealed any geographic trends in the allozyme data. The very different distributions for height and allozyme variation suggest that evolutionary forces are acting in different ways on the genes controlling these traits, and that allozyme data will have limited value in developing sampling strategies for gene conservation programs, where the preservation of germ plasm adapted to many sites throughout a species range is important.


1992 ◽  
Vol 70 (11) ◽  
pp. 2132-2138 ◽  
Author(s):  
D. T. Quiring

Field studies were carried out over 2 years to determine the effect of age of white spruce (Picea glauca) leaves on the development of the spruce bud moth, Zeiraphera canadensis Mut. &Free. (Lepidoptera: Tortricidae). In both years developing buds remained suitable for first-instar larvae for only 4–5 days after bud burst, after which survivorship decreased significantly. Individuals that survived on flaring shoots were smaller than those placed on newly burst buds. Although leaf contents of water, nitrogen, and several minerals were inversely related to leafage, only declines in N and P content were associated with the rapid change in host suitability. Differences in N and P contents were small, however, suggesting that the rapid decline in host suitability was also due to the influence of other, unmeasured factors. When larvae were placed on foliage of the same age, their survival was similar on trees in half-sib families with high or low susceptibility to Z. canadensis. Thus, variations in susceptibility of white spruce to Z. canadensis might be associated with differences in host-plant phenology but are not due to differences in nutritional quality. This study demonstrates that the phenological window for establishment of newly emerged folivores may be shorter than is commonly thought.


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