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.

Hardening and dehardening of shoots and roots of containerized black spruce and white spruce seedlings under short and long days

1992 ◽  
Vol 22 (3) ◽  
pp. 388-396 ◽  
Author(s):  
Francine J. Blgras ◽  
André L. D'aoust
Keyword(s):  
Mineral Content ◽  
Black Spruce ◽  
Day Treatment ◽  
White Spruce ◽  
Bud Break ◽  
Temperature Changes ◽  
Short Day ◽  
Long Day ◽  
Significant Difference ◽  
Response To Temperature

Containerized black spruce (Piceamariana (Mill.) B.S.P.) and white spruce (Piceaglauca (Moench) Voss) seedlings that were 120 days old were acclimated under short-day (8-h photoperiod) and long-day (16-h photoperiod) conditions at 10 °C for 12 h and 5 °C for 12 h for 28 days. Afterwards, they were exposed to 3 °C (8-h photoperiod) for 21 days and to 0 °C (without light) for 28 days. Finally, seedlings were dehardened at 10 °C (14-h photoperiod) for 21 days. Hardening of needles, excised stem parts, and whole seedlings was increased by short-day treatment, whereas roots hardened only in response to lowering of temperature. Whole seedlings and needles exposed to the short-day treatment dehardened earlier, whereas roots dehardened only in response to temperature changes. Bud formation was not influenced by photoperiod treatment, but seedlings exposed to the short-day treatment had an earlier bud break. No significant difference was observed between photoperiod treatments for water, sugar, and mineral content of shoots and roots prior to or during dehardening.

The apparent behaviour of maize and sorghum stomata during and after drought

1959 ◽  
Vol 53 (3) ◽  
pp. 412-416 ◽  
Author(s):  
J. Glover
Keyword(s):  
Water Supply ◽  
The Other ◽  
Severe Drought ◽  
Young Plant ◽  
Normal Behaviour ◽  
Other Hand ◽  
Grain Crop

Maize stomata are shown to be markedly affected by severe drought lasting about a week or more, in that they do not recover their apparent pattern of normal behaviour after the water supply to the plant is restored, although the leaves regain their turgidity and seem normal. On the other hand, sorghum stomata recover well from severe drought lasting 14 days and their recovery follows fairly closely behind the restoration of turgidity to the leaves. It is suggested that this difference in ability of stomata to recover from severe drought in some measure accounts for the superiority of sorghum as a grain crop in dry regions.Severe drought in maize is shown to be less damaging to the young plant than to the old, because the stomata of the unopened leaves behave normally when unfolded after the drought is broken.

Frost hardiness, height, and dormancy of 15 short-day, nursery-treated interior spruce seed lots

2000 ◽  
Vol 30 (7) ◽  
pp. 1096-1105 ◽  
Author(s):  
C DB Hawkins ◽  
K B Shewan
Keyword(s):  
Picea Glauca ◽  
Day Treatment ◽  
Field Performance ◽  
Seed Orchard ◽  
Frost Hardiness ◽  
Control Treatment ◽  
Short Day ◽  
Physiological Processes ◽  
Interior Spruce ◽  
Day Nursery

Fifteen seed lots, five each from natural-stand, seed-orchard, and full-sib collections, of interior spruce (Picea glauca (Moench) Voss, Picea engelmannii Parry ex Engelm., and their naturally occurring hybrids) were sown in February 1993. One half of each seed lot received an ambient photoperiod (control) treatment, while the other half got a blackout (short-day) treatment. All seedlings were grown under ambient photoperiod except during the 17 days of blackout. Frost hardiness assessments were done between July and May. Blackout treatment was effective in regulating height and promoting frost hardiness in all seed lots, particularly vigorous ones. Seed lots originating from high latitude or elevation were more frost hardy both at fall lift and spring planting. Full-sib seed lots from similar latitude displayed no elevational frost-hardiness trend. Blackout treatment promoted seedling dormancy (estimated with days to bud break) at lift, but it had little or no effect on dormancy at planting. Seedling dormancy and frost hardiness were acquired and lost differently, suggesting that they are independent physiological processes. Blackout treatment significantly reduced new roots at planting in all lots. This could retard early field performance and negate the apparent utility of blackout treatment.

scholarly journals Photoperiodic Response of Peanut Species1

1983 ◽  
Vol 10 (2) ◽  
pp. 59-62 ◽  
Author(s):  
H. T. Stalker ◽  
J. C. Wynne
Keyword(s):  
North Carolina ◽  
Day Treatment ◽  
Photoperiodic Response ◽  
Reproductive Capacity ◽  
Arachis Species ◽  
Short Day ◽  
The North ◽  
Long Day ◽  
Wild Peanut ◽  
Short Days

Abstract Many Arachis species collections do not produce pegs in North Carolina even though they flower profusely. To investigate reasons for the failure of fruiting, nine wild peanut species of section Arachis and three A. hypogaea cultivars representing spanish, valencia and virginia types were evaluated for response to short and long-day treatments in the North Carolina State Phytotron Unit of the Southeastern Environmental Laboratories. The objective of this investigation was to determine the flowering and fruiting responses of Arachis species to short and long-day photoperiods. Plant collections grown under a 9-hour short-day treatment were generally less vigorous, but produced more pegs than corresponding plants grown in long-day treatments which were produced by 9 hours of light plus a 3-hour interruption of the dark period. Annual species produced significantly more flowers and pegs than perennial species during both long and short days. The total number of flowers produced ranged from 0 during short days for A. correntina to more than 300 for A. cardenasii in long-day treatments. Only one plant of each species A. chacoense and A. villosa, and no plants of A. correntina, flowered in short days. Total numbers of pegs produced in short-day treatments were generally greater than in long-day treatments and the ratio of total number of pegs/total number of flowers was consistently greater during short-day treatments. A general trend was observed for more flowers produced in long-day treatments, but more pegs produced in short days. This study indicated that photoperiod can be manipulated to increase the seed set of some species and the success rate of obtaining certain interspecific hybrids. Furthermore, introgression from wild to cultivated species may possibly alter the reproductive capacity of A. hypogaea to photoperiod.

Differential drought resistance strategies of co-existing woodland species enduring the long rainless Eastern Mediterranean summer

2019 ◽  
Vol 40 (3) ◽  
pp. 305-320 ◽  
Author(s):  
Päivi J Väänänen ◽  
Yagil Osem ◽  
Shabtai Cohen ◽  
José M Grünzweig
Keyword(s):  
Drought Resistance ◽  
Tree Mortality ◽  
Eastern Mediterranean ◽  
Stomatal Closure ◽  
Woody Species ◽  
The Other ◽  
Severe Drought ◽  
Resistance Strategies ◽  
Safety Margins ◽  
Species Specific

Abstract In anticipation of a drier climate and to project future changes in forest dynamics, it is imperative to understand species-specific differences in drought resistance. The objectives of this study were to form a comprehensive understanding of the drought resistance strategies adopted by Eastern Mediterranean woodland species, and to elaborate specific ecophysiological traits that can explain the observed variation in survival among these species. We examined leaf water potential (𝛹), gas exchange and stem hydraulics during 2–3 years in mature individuals of the key woody species Phillyrea latifolia L., Pistacia lentiscus L. and Quercus calliprinos Webb that co-exist in a dry woodland experiencing ~ 6 rainless summer months. As compared with the other two similarly functioning species, Phillyrea displayed considerably lower 𝛹 (minimum 𝛹 of −8.7 MPa in Phillyrea vs −4.2 MPa in Pistacia and Quercus), lower 𝛹 at stomatal closure and lower leaf turgor loss point (𝛹TLP ), but reduced hydraulic vulnerability and wider safety margins. Notably, Phillyrea allowed 𝛹 to drop below 𝛹TLP under severe drought, whereas the other two species maintained positive turgor. These results indicate that Phillyrea adopted a more anisohydric drought resistance strategy, while Pistacia and Quercus exhibited a more isohydric strategy and probably relied on deeper water reserves. Unlike the two relatively isohydric species, Phillyrea reached complete stomatal closure at the end of the dry summer. Despite assessing a large number of physiological traits, none of them could be directly related to tree mortality. Higher mortality was observed for Quercus than for the other two species, which may result from higher water consumption due to its 2.5–10 times larger crown volume. The observed patterns suggest that similar levels of drought resistance in terms of survival can be achieved via different drought resistance strategies. Conversely, similar resistance strategies in terms of isohydricity can lead to different levels of vulnerability to extreme drought.

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.

scholarly journals Chrysanthemum Cultivars Differ in Response to Photoperiod when Grown under Far-red Absorbing Filters

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 437A-437
Author(s):  
M.J. McMahon
Keyword(s):  
Acetic Acid ◽  
Ethyl Alcohol ◽  
The Other ◽  
Short Day ◽  
Long Day ◽  
Floral Primordia ◽  
Lateral Branches ◽  
And Control ◽  
Short Days

Two chrysanthemum [Dendranthema × grandiflorum (Ramat) Kitamura] cultivars, Bright Golden Anne and Spears, were grown in unfiltered sunlight (control) or under filters that removed far-red (FR) light under long- or short-day photoperiods for a total of four treatments. Eight plants from each cultivar were exposed to each treatment. Tips of lateral branches were harvested every 3 days and preserved in formalin, acetic acid, 70% ethyl alcohol (5:5:90 by volume), then observed and photographed under a dissecting microscope. In `Spears', all short-day treatments developed floral primoridia at the same time and rate and the development was normal. Under long days and under FR-absorbing filters, floral primordia initiated and developed normally, but was delayed several days compared to short days. Plants under long days and control filters also developed normal primoridia, but at a slower rate than any of the other treatments. In `Bright Golden Anne', only short-day treatments developed normal floral primordia. Development was the same regardless of filter. Under long days, plants under FR-absorbing filters eventually initiated floral primordia, but development was abnormal. No floral primordia developed under long-day and control filter conditions. In all cases, `Spears' primoridia development was much more rapid than `Bright Golden Anne'.

Short day—long day treatment of acyclic mares

2000 ◽  
Vol 20 (10) ◽  
pp. 634
Keyword(s):  
Day Treatment ◽  
Short Day ◽  
Long Day

Influence of photoperiod on shoot and root frost tolerance and bud phenology of white spruce seedlings (Piceaglauca)

1993 ◽  
Vol 23 (2) ◽  
pp. 219-228 ◽  
Author(s):  
Francine J. Bigras ◽  
André L. D'Aoust
Keyword(s):  
Day Treatment ◽  
Frost Damage ◽  
Frost Tolerance ◽  
Dry Mass ◽  
Bud Break ◽  
Treatment Delays ◽  
Short Day ◽  
Apical Buds ◽  
Long Day ◽  
Dead Tissue

To determine frost tolerance of shoots and roots and the phenology of apical buds under different photoperiods during hardening and dehardening, 16-week-old white spruce seedlings (Piceaglauca (Moench) Voss) were hardened in growth chambers under 8-, 10-, 12-, and 14-h photoperiods for 14 d at 15:10 °C, followed by 14 d at each of the day:night temperatures of 12:8 °C, 10:5 °C, 5:2 °C under 13-h photoperiod, and finally, stored for 35 d at 0:0 °C in darkness. Afterwards, deacclimation conditions consisted of 14 d at 10:5 °C and 17 d at 15:10 °C with 15-h photoperiod. Frost tolerance was assessed at intervals, and phenology of apical buds was monitored by visual examination. The root dry mass remaining after removal of dead tissue was weighed 30 d after the freezing test to estimate frost damage to the root system. Results showed that hardening of shoots was influenced by photoperiod, whereas hardening of roots responded only to temperature. Frost tolerance of shoots was enhanced and bud formation accelerated under 8-h photoperiod. After 56 d of acclimation, frost tolerance of shoots reached −30, −17, −17, and −12 °C under photoperiods of 8, 10, 12, and 14 h, respectively. Bud break occurred earlier, in a similar fashion for plants treated with 8- and 10-h photoperiods. The root dry mass remaining after removal of dead tissue provided a reliable estimate of frost damage to root systems. Finally, we propose that short-day treatment accelerates and long-day treatment delays the dormancy development, thus causing all developmental processes to be affected. Consequently, hardiness development can also be accelerated by short-day treatment or delayed by long-day treatment, resulting in faster rates of hardening, dehardening, and bud break for seedlings of the short-day treatment, whereas long-day treatment delays those processes. These results complement the analysis of dehardening and bud break in the degree growth stage model described by L.H. Fuchigami and coworkers.

scholarly journals Creating boreal mixedwoods by planting spruce under aspen: successful establishment in uncertain future climates

2016 ◽  
Vol 46 (10) ◽  
pp. 1217-1223 ◽  
Author(s):  
Richard Kabzems ◽  
Philip G. Comeau ◽  
Cosmin N. Filipescu ◽  
Bruce Rogers ◽  
Amanda F. Linnell Nemec
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Basal Area ◽  
Cost Effective ◽  
White Spruce ◽  
Understory Vegetation ◽  
Severe Drought ◽  
Boreal Mixedwoods ◽  
Uncertain Future ◽  
Canadian Boreal Forest

Planting white spruce (Picea glauca (Moench) Voss) under established aspen (Populus tremuloides Michx.) stands has substantial potential for regenerating mixedwood ecosystems in the western Canadian boreal forest. The presence of an aspen overstory serves to ameliorate frost and winter injury problems and suppresses understory vegetation that may compete with white spruce. Under future climatic regimes with more frequent and severe drought episodes, underplanting may be a cost-effective strategy for lowering the risk of mortality in mixedwood regeneration. We examine the growth of white spruce during the first 18 years after being planted beneath a 39-year-old stand of trembling aspen. Treatments included thinning from over 6000 stems·ha−1 to 3000, 2000, and 1000 stems·ha−1 and fertilization. Initial stimulation of understory vegetation by fertilization had no measureable effect on spruce heights or diameters at year 18. Aspen thinning treatments did not have a significant effect on spruce height growth rates after spruce crowns had emerged above the understory shrub layer due to rapid aspen basal area increases after thinning. Small, but significant, increases for spruce height and diameter were present in the 1000 and 2000 stem·ha−1 aspen thinnings. A much wider range of aspen stand conditions may be suitable for planting spruce to create mixedwood ecosystems than has been previously considered.

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