Development of the shoot apex of blue spruce (Piceapungens)

1977 ◽  
Vol 7 (4) ◽  
pp. 614-620 ◽  
Author(s):  
Eric Young ◽  
James W. Hanover
Keyword(s):  
Shoot Apex ◽  
Continuous Light ◽  
Scale Formation ◽  
Seasonal Development ◽  
Bud Break ◽  
Blue Spruce ◽  
Bud Set ◽  
Significant Difference ◽  
Short Days ◽  
Needle Primordia

Blue spruce (Piceapungens Engelm.) seedlings grown in a nursery for 1 to 5 years and seedlings grown from seed in a greenhouse under continuous light for 2 to 6 months were studied to determine (1) time to bud set on transfer to short days, (2) time to bud-break on subsequent transfer to long days, and (3) the anatomy of the dormant shoot apex. Seasonal development of the shoot apex of a single 50-year-old blue spruce was also monitored.Time to but set on transfer to short days decreased after long periods under continuous light. Time to budbreak on subsequent transfer to long days increased with increasing age in nursery- and greenhouse-grown seedlings. The dormant shoot apex became more highly differentiated as the nursery-grown seedlings aged from 1 to 3 years, then showed no significant difference after 3 years of age.The 50-year-old blue spruce initiated many new needles in the current bud before bud scale formation, which began in mid-May. Needle primordia initiation in the new bud began in late June and slowed down in late August. Apical dome diameter increased and decreased concurrently with the increase and decrease in rate of needle primordia initiation.

Production physiology and morphology of Populus species and their hybrids grown under short rotation. I. Clonal comparisons of 4-year growth and phenology

1992 ◽  
Vol 22 (12) ◽  
pp. 1937-1948 ◽  
Author(s):  
R. Ceulemans ◽  
G. Scarascia-Mugnozza ◽  
B. M. Wiard ◽  
J. H. Braatne ◽  
T. M. Hinckley ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Volume Growth ◽  
Stem Volume ◽  
Clonal Variation ◽  
Diameter Growth ◽  
Bud Break ◽  
Short Rotation ◽  
Hybrid Superiority ◽  
Bud Set ◽  
Number Of Branches

Height and diameter growth, stem volume production, leaf phenology and leaf number, and number of branches of Populustrichocarpa Torr. & Gray, Populusdeltoides Bartr., and their F1 hybrids (P. trichocarpa × P. deltoides) were studied for 4 years in a research plantation in western Washington, United States. Twelve clones (three of each species and six of the hybrids) grew under a short-rotation silviculture regime in monoclonal plots at spacings of 1 × 1 m (10 000 stems/ha). Clones represented a north-south gradient within the geographic distribution of both the two North American poplar species and the parentage of the hybrid material. The results support earlier work by contributing additional evidence for the superiority of the hybrids. However, the relative hybrid superiority in these monoclonal plots was less pronounced than that found earlier in field trials with single-tree plots because of heightened intraclonal competition. After 4 years, mean estimated stem volume of the hybrids was 1.5 times that of P. trichocarpa and 2.3 times that of P. deltoides. Total tree height of the hybrids was 1.1 times that off. trichocarpa and 1.3 times that off. deltoides. Clonal variation was the dominant theme in height and diameter growth, stem volume productivity, time of bud break and bud set, tree mortality, and number of branches. Populustrichocarpa had the highest number of sylleptic branches, P. deltoides had the lowest, and hybrids were intermediate. Significant clone by replicate interactions were observed in height, diameter, and volume growth. Phenological traits, such as the dates of bud break and bud set, and the length of growing period only partly explained the observed differences in growth between the P. trichocarpa × P. deltoides hybrids and the parental species.

scholarly journals Intermittent Short Days and Chilling, and Benzylaminopurine Affect the Growth and Morphology of Fraser fir Seedlings

1992 ◽  
Vol 10 (4) ◽  
pp. 205-207
Author(s):  
Ben H. Cazell ◽  
John R. Seiler
Keyword(s):  
Foliar Application ◽  
Height Growth ◽  
Abies Fraseri ◽  
Fraser Fir ◽  
Accelerate Growth ◽  
Bud Set ◽  
Collar Diameter ◽  
Chilling Period ◽  
Root Collar ◽  
Short Days

Abstract Fraser fir (Abies fraseri (Pursh.) Poir.) seedlings were either grown continuously under long days (16 hr) or intermittently exposed to short days (8 hr) to induce bud set followed by a chilling period. Additionally, half the seedlings in each treatment received a foliar application of 444 uM benzylaminopurine (BAP). Seedlings that were allowed to set buds, followed by chilling, obtained the greatest height, but this treatment in combination with BAP reduced seedling height. BAP applied to seedlings grown continuously under long days stimulated height growth and prevented long dormant periods typical for non-chilled seedlings. Continuously grown, BAP-treated seedlings had 1.3 times larger root collar diameter, and 1.7 times more biomass, compared to other treatments. Root/shoot ratios for continuously grown, BAP-treated seedlings were comparable to intermittently chilled, non-BAP treated seedlings. These results suggest that either intermittent short days followed by chilling, or foliar BAP applications can be used to accelerate growth of containerized Fraser fir seedlings. However, the combination of chilling and BAP resulted in poorer development than either treatment alone.

scholarly journals 030 GENOTYPIC AND PHENOTYPIC FIELD GROWTH CORRELATIONS OF MICROPROPAGATED SILVER MAPLE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 432a-432
Author(s):  
John E. Preece ◽  
Carl A. Huetteman ◽  
W. Clark Ashby ◽  
Paul L. Roth ◽  
Richard G. Adams
Keyword(s):  
Growth Parameters ◽  
Tree Height ◽  
Bud Break ◽  
Silver Maple ◽  
Crown Volume ◽  
In Vitro Micropropagation ◽  
Bud Set ◽  
Genotypic And Phenotypic Correlations ◽  
Growth Correlations

Sixty clones (four clones from each of 15 provenances) were micropropagated and planted in replicated plots in lowland and upland sites in Carbondale, IL in 1991. Data were collected on tree growth, including basal caliper, height, branching, crown volume, dates of bud break, bud set, and leaf fall. There were significant and strong positive genotypic and phenotypic correlations between tree height and basal caliper throughout the three years of growth. During 1993, bud break was not significantly correlated with any growth parameters. After three years in the field, tree height was significantly negatively correlated with the amount of callus that had formed after one month during the in vitro micropropagation phase. However, all shoots that formed in vitro were of axillary origin.

scholarly journals Echinacea purpurea `Magnus': Is It an Intermediate-day or a Short-day/Long-day Plant?

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1100D-1100
Author(s):  
Ki Sun Kim ◽  
Art Cameron ◽  
Erik S. Runkle
Keyword(s):  
Developmental Stage ◽  
Continuous Light ◽  
Echinacea Purpurea ◽  
Flower Induction ◽  
Research Groups ◽  
Short Day ◽  
Purple Coneflower ◽  
Long Day ◽  
Primary Induction ◽  
Short Days

Echinacea purpurea Moench., or purple coneflower, has been classified both as an intermediate-day plant and a short-day/long-day plant by different research groups. We performed experiments to determine at what developmental stage Echinacea`Magnus' became sensitive to inductive photoperiods, and identified photoperiods that induced the most rapid flowering. Seedlings were raised under continuous light in 128-cell plug trays, then were transplanted into 11.4-cm plastic pots. Plants were transferred to 10-hour short days (sd) once seedlings developed 3, 4, 5, 6, 7, or 8 true leaves. After 4 or 6 weeks of sd treatment (primary induction), plants were moved to 16- or 24-hour photoperiods until flowering (secondary induction). Plants were also grown under continuous 10-, 14-, and 24-hour photoperiods to serve as controls. At least 4 leaves were required for flower induction; flowering was delayed and the percentage was low when plants had 3 leaves at the beginning of primary induction. Plants under continuous 14-hour photoperiods had the highest flower percentage (100%) and flowered earliest (87 days). Plants under continuous 10- and 24-hour photoperiods did not flower. Four weeks of sd followed by 16-hour photoperiods induced complete flowering and in an average of 95 days. However, 6 weeks sd was required for 100% flowering when the final photoperiod was 24 hours.

Natural Variation Among Seedlings from Colorado Sources of Blue Spruce

1988 ◽  
Vol 3 (4) ◽  
pp. 106-109
Author(s):  
Kenneth E. Diebel ◽  
Gilbert H. Fechner
Keyword(s):  
Seed Weight ◽  
Natural Variation ◽  
Height Growth ◽  
Blue Spruce ◽  
Picea Pungens ◽  
Single Tree ◽  
Bud Set ◽  
Seed Zone ◽  
Nested Analysis ◽  
Germination Value

Abstract Germination value, seed weight, cotyledon number, cone length, date of bud set, and height growth were examined on 75 single-tree Colorado sources of blue spruce (Picea pungens Engelm.) grown under accelerated conditions in a greenhouse. The 75 sources were grouped according to seed zone of origin; and nested analysis of variance indicated significant differences between zones for all traits except cotyledon number and date of bud set. No differences were found among families (grouped according to subregions) within seed zones. Trees in families from low elevations and southern latitudes set bud later than trees of other origins. Variation in date of bud set conformed to local altitudinal clinal patterns. West. J. Appl. For. 2(4):106-109, October 1988.

Stunting in 'Gigas' Wheat as Influenced by Temperature and Daylength

1986 ◽  
Vol 13 (3) ◽  
pp. 381 ◽  
Author(s):  
D Atsmon ◽  
MG Bush ◽  
LT Evans
Keyword(s):  
Shoot Apex ◽  
Wheat Line ◽  
Temperature Regimes ◽  
Pass Through ◽  
Short Days ◽  
Double Ridge

When plants of the uniculm 'gigas' wheat line 492 were grown at 15/ 10°C, all plants were severely stunted in long days (LD) but normal in short days (SD). The results of reciprocal transfers between SD and LD indicate that line 492 plants pass through a stage which is very sensitive to LD at 15/ 10°C, between about 14 and 27 days after sowing, just before double ridge formation at the shoot apex. LD during that interval caused stunting in most plants whereas SD at that stage allowed all plants to develop normally. Transfers between temperature regimes of 15/10°C and 24/19°C under LD also indicated that the period just prior to double ridge formation was critical for stunting. In the uniculm line 492 stunting in LD was caused by temperature regimes cooler than 21 /16°C;, whereas in the oligoculm line 380 the main shoots of most plants were normal even at 15/ 10°C.

Ethylene and ethane evolution during cold acclimation and deacclimation of ponderosa pine

1991 ◽  
Vol 21 (5) ◽  
pp. 601-605 ◽  
Author(s):  
Karen E. Burr ◽  
Stephen J. Wallner ◽  
Richard W. Tinus
Keyword(s):  
Cold Acclimation ◽  
Ponderosa Pine ◽  
Cold Hardiness ◽  
Sharp Decrease ◽  
Standard Errors ◽  
Bud Break ◽  
Ethylene Evolution ◽  
Bud Set ◽  
Growth Chambers ◽  
Over Time

Greenhouse container-grown ponderosa pine (Pinusponderosa var. scopulorum Engelm.) were cold acclimated and deacclimated in growth chambers during a 19-week regime. Seedling cold hardiness, bud dormancy, and ethylene and ethane evolution from excised needles were measured weekly. Ethylene and ethane evolution and the ethane/ethylene ratio declined from bud set to bud break and did not parallel changes in cold hardiness. Large standard errors of the ethylene evolution means made detecting statistical differences over time difficult. Significant deviations in the ethane evolution means were observed, however, and indicated a sharp decrease and recovery at the start of cold acclimation and a peak at the start of deacclimation. The ethane/ethylene ratio accentuated the declining trend from bud set to bud break and the two sharp deviations in the trend at the start of acclimation and deacclimation.

Relative attractiveness of colour traps to pear psylla in relation to seasonal changes in pear phenology

2010 ◽  
Vol 142 (2) ◽  
pp. 188-191 ◽  
Author(s):  
W.R. Cooper ◽  
G.J. Puterka ◽  
D.M. Glenn
Keyword(s):  
Seasonal Changes ◽  
The United States ◽  
Bud Break ◽  
Phenological Stages ◽  
Proactive Management ◽  
Pear Psylla ◽  
Significant Difference ◽  
Yellow Traps ◽  
Relative Attractiveness ◽  
Gender Based

AbstractMonitoring of pear psylla (Cacopsylla pyricola (Förster), Hemiptera: Psyllidae) prior to spring bud break could aid in predicting the size of subsequent spring populations and lead to improved proactive management decisions. Yellow traps are commonly used to monitor hemipteran pests including pear psylla, but very little is known regarding seasonal changes in attractiveness of yellow traps or relative attractiveness of colours other than yellow. This study presents seasonal colour-trap preferences of pear psyllas based on pear (Pyrus communis L., Rosaceae) phenological stages in the mid-Atlantic region of the United States of America. Black, blue, brown, clear (colourless), green, orange, red, white, and yellow traps were assayed against wild adult psylla populations over a 2-year period. Pear psyllas had a strong preference for yellow and orange when green leaves were present; however, we found no statistically significant difference between traps of different colours prior to spring bud break. Significantly more female psyllas were caught overall, but there was no gender-based colour bias. None of our colour traps caught significantly fewer psyllas than did clear (background hue) traps, suggesting that no traps were repellent.

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